Merge branch 'master' into clear_all_environments_log_by_default

132 files changed, 1253 insertions, 981 deletions

diff --git a/actionpack/CHANGELOG.md b/actionpack/CHANGELOG.md
index eef3db8f24..2f0c677ad1 100644
--- a/actionpack/CHANGELOG.md
+++ b/actionpack/CHANGELOG.md
@@ -1,3 +1,51 @@
+*   Use accept header in integration tests with `as: :json`
+
+    Instead of appending the `format` to the request path, Rails will figure
+    out the format from the header instead.
+
+    This allows devs to use `:as` on routes that don't have a format.
+
+    Fixes #27144.
+
+    *Kasper Timm Hansen*
+
+*   Reset a new session directly after its creation in `ActionDispatch::IntegrationTest#open_session`.
+
+    Fixes #22742.
+
+    *Tawan Sierek*
+
+*   Fixes incorrect output from rails routes when using singular resources.
+
+    Fixes #26606.
+
+    *Erick Reyna*
+
+*   Fixes multiple calls to `logger.fatal` instead of a single call,
+    for every line in an exception backtrace, when printing trace
+    from `DebugExceptions` middleware.
+
+    Fixes #26134.
+
+    *Vipul A M*
+
+*   Add support for arbitrary hashes in strong parameters:
+
+    ```ruby
+    params.permit(preferences: {})
+    ```
+
+    *Xavier Noria*
+
+*   Add `ActionController::Parameters#merge!`, which behaves the same as `Hash#merge!`.
+
+    *Yuji Yaginuma*
+
+*   Allow keys not found in `RACK_KEY_TRANSLATION` for setting the environment when rendering
+    arbitrary templates.
+
+    *Sammy Larbi*
+
 *   Remove deprecated support to non-keyword arguments in `ActionDispatch::IntegrationTest#process`,
     `#get`, `#post`, `#patch`, `#put`, `#delete`, and `#head`.
 
diff --git a/actionpack/bin/test b/actionpack/bin/test
index 84a05bba08..a7beb14b27 100755
--- a/actionpack/bin/test
+++ b/actionpack/bin/test
@@ -2,5 +2,3 @@
 
 COMPONENT_ROOT = File.expand_path("..", __dir__)
 require File.expand_path("../tools/test", COMPONENT_ROOT)
-
-exit Minitest.run(ARGV)
diff --git a/actionpack/lib/abstract_controller/base.rb b/actionpack/lib/abstract_controller/base.rb
index 8e588812f8..603c2e9ea7 100644
--- a/actionpack/lib/abstract_controller/base.rb
+++ b/actionpack/lib/abstract_controller/base.rb
@@ -215,7 +215,7 @@ module AbstractController
       # ==== Returns
       # * <tt>string</tt> - The name of the method that handles the action
       # * false           - No valid method name could be found.
-      # Raise AbstractController::ActionNotFound.
+      # Raise +AbstractController::ActionNotFound+.
       def _find_action_name(action_name)
         _valid_action_name?(action_name) && method_for_action(action_name)
       end
@@ -231,11 +231,11 @@ module AbstractController
       # with a template matching the action name is considered to exist.
       #
       # If you override this method to handle additional cases, you may
-      # also provide a method (like _handle_method_missing) to handle
+      # also provide a method (like +_handle_method_missing+) to handle
       # the case.
       #
-      # If none of these conditions are true, and method_for_action
-      # returns nil, an AbstractController::ActionNotFound exception will be raised.
+      # If none of these conditions are true, and +method_for_action+
+      # returns +nil+, an +AbstractController::ActionNotFound+ exception will be raised.
       #
       # ==== Parameters
       # * <tt>action_name</tt> - An action name to find a method name for
diff --git a/actionpack/lib/abstract_controller/caching.rb b/actionpack/lib/abstract_controller/caching.rb
index d222880922..26e3f08bc1 100644
--- a/actionpack/lib/abstract_controller/caching.rb
+++ b/actionpack/lib/abstract_controller/caching.rb
@@ -52,9 +52,9 @@ module AbstractController
       self.class._view_cache_dependencies.map { |dep| instance_exec(&dep) }.compact
     end
 
-    protected
+    private
       # Convenience accessor.
-      def cache(key, options = {}, &block)
+      def cache(key, options = {}, &block) # :doc:
         if cache_configured?
           cache_store.fetch(ActiveSupport::Cache.expand_cache_key(key, :controller), options, &block)
         else
diff --git a/actionpack/lib/abstract_controller/collector.rb b/actionpack/lib/abstract_controller/collector.rb
index 57714b0588..40ae5aa1ca 100644
--- a/actionpack/lib/abstract_controller/collector.rb
+++ b/actionpack/lib/abstract_controller/collector.rb
@@ -19,7 +19,7 @@ module AbstractController
       generate_method_for_mime(mime) unless instance_methods.include?(mime.to_sym)
     end
 
-  protected
+  private
 
     def method_missing(symbol, &block)
       unless mime_constant = Mime[symbol]
diff --git a/actionpack/lib/abstract_controller/rendering.rb b/actionpack/lib/abstract_controller/rendering.rb
index 2cb22cb53d..d339580435 100644
--- a/actionpack/lib/abstract_controller/rendering.rb
+++ b/actionpack/lib/abstract_controller/rendering.rb
@@ -1,6 +1,4 @@
 require "abstract_controller/error"
-require "active_support/concern"
-require "active_support/core_ext/class/attribute"
 require "action_view"
 require "action_view/view_paths"
 require "set"
@@ -80,7 +78,7 @@ module AbstractController
     # <tt>render :action => "foo"</tt> and <tt>render "foo/bar"</tt> to
     # <tt>render :file => "foo/bar"</tt>.
     # :api: plugin
-    def _normalize_args(action=nil, options={})
+    def _normalize_args(action = nil, options = {})
       if action.respond_to?(:permitted?)
         if action.permitted?
           action
diff --git a/actionpack/lib/action_controller/metal.rb b/actionpack/lib/action_controller/metal.rb
index ed93a2f09c..9dab7aeef4 100644
--- a/actionpack/lib/action_controller/metal.rb
+++ b/actionpack/lib/action_controller/metal.rb
@@ -139,8 +139,8 @@ module ActionController
       end
     end
 
-    def self.encoding_for_param(action, param) # :nodoc:
-      ::Encoding::UTF_8
+    def self.binary_params_for?(action) # :nodoc:
+      false
     end
 
     # Delegates to the class' <tt>controller_name</tt>
diff --git a/actionpack/lib/action_controller/metal/conditional_get.rb b/actionpack/lib/action_controller/metal/conditional_get.rb
index 89bf60a0bb..eb636fa3f6 100644
--- a/actionpack/lib/action_controller/metal/conditional_get.rb
+++ b/actionpack/lib/action_controller/metal/conditional_get.rb
@@ -238,7 +238,7 @@ module ActionController
       )
       options.delete(:private)
 
-      response.cache_control[:extras] = options.map { |k,v| "#{k}=#{v}" }
+      response.cache_control[:extras] = options.map { |k, v| "#{k}=#{v}" }
       response.date = Time.now unless response.date?
     end
 
diff --git a/actionpack/lib/action_controller/metal/data_streaming.rb b/actionpack/lib/action_controller/metal/data_streaming.rb
index f089c8423b..731e03e2fc 100644
--- a/actionpack/lib/action_controller/metal/data_streaming.rb
+++ b/actionpack/lib/action_controller/metal/data_streaming.rb
@@ -11,7 +11,7 @@ module ActionController #:nodoc:
     DEFAULT_SEND_FILE_TYPE        = "application/octet-stream".freeze #:nodoc:
     DEFAULT_SEND_FILE_DISPOSITION = "attachment".freeze #:nodoc:
 
-    protected
+    private
       # Sends the file. This uses a server-appropriate method (such as X-Sendfile)
       # via the Rack::Sendfile middleware. The header to use is set via
       # +config.action_dispatch.x_sendfile_header+.
@@ -70,7 +70,6 @@ module ActionController #:nodoc:
         send_file_headers! options
 
         self.status = options[:status] || 200
-        self.content_type = options[:type] if options.key?(:type)
         self.content_type = options[:content_type] if options.key?(:content_type)
         response.send_file path
       end
@@ -109,10 +108,12 @@ module ActionController #:nodoc:
         render options.slice(:status, :content_type).merge(body: data)
       end
 
-    private
       def send_file_headers!(options)
         type_provided = options.has_key?(:type)
 
+        self.content_type = DEFAULT_SEND_FILE_TYPE
+        response.sending_file = true
+
         content_type = options.fetch(:type, DEFAULT_SEND_FILE_TYPE)
         raise ArgumentError, ":type option required" if content_type.nil?
 
@@ -137,8 +138,6 @@ module ActionController #:nodoc:
 
         headers["Content-Transfer-Encoding"] = "binary"
 
-        response.sending_file = true
-
         # Fix a problem with IE 6.0 on opening downloaded files:
         # If Cache-Control: no-cache is set (which Rails does by default),
         # IE removes the file it just downloaded from its cache immediately
diff --git a/actionpack/lib/action_controller/metal/etag_with_template_digest.rb b/actionpack/lib/action_controller/metal/etag_with_template_digest.rb
index 6c103bb042..798564db96 100644
--- a/actionpack/lib/action_controller/metal/etag_with_template_digest.rb
+++ b/actionpack/lib/action_controller/metal/etag_with_template_digest.rb
@@ -40,7 +40,7 @@ module ActionController
       end
 
       # Pick the template digest to include in the ETag. If the +:template+ option
-      # is present, use the named template. If +:template+ is nil or absent, use
+      # is present, use the named template. If +:template+ is +nil+ or absent, use
       # the default controller/action template. If +:template+ is false, omit the
       # template digest from the ETag.
       def pick_template_for_etag(options)
diff --git a/actionpack/lib/action_controller/metal/exceptions.rb b/actionpack/lib/action_controller/metal/exceptions.rb
index 3761e6172b..175dd9eb9e 100644
--- a/actionpack/lib/action_controller/metal/exceptions.rb
+++ b/actionpack/lib/action_controller/metal/exceptions.rb
@@ -14,7 +14,7 @@ module ActionController
 
   class RoutingError < ActionControllerError #:nodoc:
     attr_reader :failures
-    def initialize(message, failures=[])
+    def initialize(message, failures = [])
       super(message)
       @failures = failures
     end
diff --git a/actionpack/lib/action_controller/metal/flash.rb b/actionpack/lib/action_controller/metal/flash.rb
index 65351284b9..347fbf0e74 100644
--- a/actionpack/lib/action_controller/metal/flash.rb
+++ b/actionpack/lib/action_controller/metal/flash.rb
@@ -42,7 +42,7 @@ module ActionController #:nodoc:
       end
     end
 
-    protected
+    private
       def redirect_to(options = {}, response_status_and_flash = {}) #:doc:
         self.class._flash_types.each do |flash_type|
           if type = response_status_and_flash.delete(flash_type)
diff --git a/actionpack/lib/action_controller/metal/force_ssl.rb b/actionpack/lib/action_controller/metal/force_ssl.rb
index b8976497a4..9d43e752ac 100644
--- a/actionpack/lib/action_controller/metal/force_ssl.rb
+++ b/actionpack/lib/action_controller/metal/force_ssl.rb
@@ -89,7 +89,7 @@ module ActionController
         end
 
         secure_url = ActionDispatch::Http::URL.url_for(options.slice(*URL_OPTIONS))
-        flash.keep if respond_to?(:flash)
+        flash.keep if respond_to?(:flash) && request.respond_to?(:flash)
         redirect_to secure_url, options.slice(*REDIRECT_OPTIONS)
       end
     end
diff --git a/actionpack/lib/action_controller/metal/http_authentication.rb b/actionpack/lib/action_controller/metal/http_authentication.rb
index a335bf109e..0575360068 100644
--- a/actionpack/lib/action_controller/metal/http_authentication.rb
+++ b/actionpack/lib/action_controller/metal/http_authentication.rb
@@ -28,7 +28,7 @@ module ActionController
     #   class ApplicationController < ActionController::Base
     #     before_action :set_account, :authenticate
     #
-    #     protected
+    #     private
     #       def set_account
     #         @account = Account.find_by(url_name: request.subdomains.first)
     #       end
@@ -224,7 +224,7 @@ module ActionController
       # Returns the expected response for a request of +http_method+ to +uri+ with the decoded +credentials+ and the expected +password+
       # Optional parameter +password_is_ha1+ is set to +true+ by default, since best practice is to store ha1 digest instead
       # of a plain-text password.
-      def expected_response(http_method, uri, credentials, password, password_is_ha1=true)
+      def expected_response(http_method, uri, credentials, password, password_is_ha1 = true)
         ha1 = password_is_ha1 ? password : ha1(credentials, password)
         ha2 = ::Digest::MD5.hexdigest([http_method.to_s.upcase, uri].join(":"))
         ::Digest::MD5.hexdigest([ha1, credentials[:nonce], credentials[:nc], credentials[:cnonce], credentials[:qop], ha2].join(":"))
@@ -246,7 +246,7 @@ module ActionController
       def decode_credentials(header)
         ActiveSupport::HashWithIndifferentAccess[header.to_s.gsub(/^Digest\s+/, "").split(",").map do |pair|
           key, value = pair.split("=", 2)
-          [key.strip, value.to_s.gsub(/^"|"$/,"").delete('\'')]
+          [key.strip, value.to_s.gsub(/^"|"$/, "").delete('\'')]
         end]
       end
 
@@ -314,7 +314,7 @@ module ActionController
       # Can be much shorter if the Stale directive is implemented. This would
       # allow a user to use new nonce without prompting the user again for their
       # username and password.
-      def validate_nonce(secret_key, request, value, seconds_to_timeout=5*60)
+      def validate_nonce(secret_key, request, value, seconds_to_timeout = 5 * 60)
         return false if value.nil?
         t = ::Base64.decode64(value).split(":").first.to_i
         nonce(secret_key, t) == value && (t - Time.now.to_i).abs <= seconds_to_timeout
@@ -363,7 +363,7 @@ module ActionController
     #   class ApplicationController < ActionController::Base
     #     before_action :set_account, :authenticate
     #
-    #     protected
+    #     private
     #       def set_account
     #         @account = Account.find_by(url_name: request.subdomains.first)
     #       end
diff --git a/actionpack/lib/action_controller/metal/instrumentation.rb b/actionpack/lib/action_controller/metal/instrumentation.rb
index 2ede96c667..924686218f 100644
--- a/actionpack/lib/action_controller/metal/instrumentation.rb
+++ b/actionpack/lib/action_controller/metal/instrumentation.rb
@@ -46,7 +46,7 @@ module ActionController
       render_output
     end
 
-    def send_file(path, options={})
+    def send_file(path, options = {})
       ActiveSupport::Notifications.instrument("send_file.action_controller",
         options.merge(path: path)) do
         super
@@ -83,14 +83,14 @@ module ActionController
     #   end
     #
     # :api: plugin
-    def cleanup_view_runtime #:nodoc:
+    def cleanup_view_runtime
       yield
     end
 
     # Every time after an action is processed, this method is invoked
     # with the payload, so you can add more information.
     # :api: plugin
-    def append_info_to_payload(payload) #:nodoc:
+    def append_info_to_payload(payload)
       payload[:view_runtime] = view_runtime
     end
 
diff --git a/actionpack/lib/action_controller/metal/live.rb b/actionpack/lib/action_controller/metal/live.rb
index 26a16104db..fed99e6c82 100644
--- a/actionpack/lib/action_controller/metal/live.rb
+++ b/actionpack/lib/action_controller/metal/live.rb
@@ -247,7 +247,7 @@ module ActionController
 
           # Since we're processing the view in a different thread, copy the
           # thread locals from the main thread to the child thread. :'(
-          locals.each { |k,v| t2[k] = v }
+          locals.each { |k, v| t2[k] = v }
 
           begin
             super(name)
diff --git a/actionpack/lib/action_controller/metal/parameter_encoding.rb b/actionpack/lib/action_controller/metal/parameter_encoding.rb
index c457fd0d06..962532ff09 100644
--- a/actionpack/lib/action_controller/metal/parameter_encoding.rb
+++ b/actionpack/lib/action_controller/metal/parameter_encoding.rb
@@ -1,5 +1,5 @@
 module ActionController
-  # Allows encoding to be specified per parameter per action.
+  # Specify binary encoding for parameters for a given action.
   module ParameterEncoding
     extend ActiveSupport::Concern
 
@@ -13,17 +13,36 @@ module ActionController
         @_parameter_encodings = {}
       end
 
-      def encoding_for_param(action, param) # :nodoc:
-        if @_parameter_encodings[action.to_s] && @_parameter_encodings[action.to_s][param.to_s]
-          @_parameter_encodings[action.to_s][param.to_s]
-        else
-          super
-        end
+      def binary_params_for?(action) # :nodoc:
+        @_parameter_encodings[action.to_s]
       end
 
-      def parameter_encoding(action, param_name, encoding)
-        @_parameter_encodings[action.to_s] ||= {}
-        @_parameter_encodings[action.to_s][param_name.to_s] = encoding
+      # Specify that a given action's parameters should all be encoded as
+      # ASCII-8BIT (it "skips" the encoding default of UTF-8).
+      #
+      # For example, a controller would use it like this:
+      #
+      #   class RepositoryController < ActionController::Base
+      #     skip_parameter_encoding :show
+      #
+      #     def show
+      #       @repo = Repository.find_by_filesystem_path params[:file_path]
+      #
+      #       # `repo_name` is guaranteed to be UTF-8, but was ASCII-8BIT, so
+      #       # tag it as such
+      #       @repo_name = params[:repo_name].force_encoding 'UTF-8'
+      #     end
+      #
+      #     def index
+      #       @repositories = Repository.all
+      #     end
+      #   end
+      #
+      # The show action in the above controller would have all parameter values
+      # encoded as ASCII-8BIT.  This is useful in the case where an application
+      # must handle data but encoding of the data is unknown, like file system data.
+      def skip_parameter_encoding(action)
+        @_parameter_encodings[action.to_s] = true
       end
     end
   end
diff --git a/actionpack/lib/action_controller/metal/params_wrapper.rb b/actionpack/lib/action_controller/metal/params_wrapper.rb
index 9d1b740025..7fc898f034 100644
--- a/actionpack/lib/action_controller/metal/params_wrapper.rb
+++ b/actionpack/lib/action_controller/metal/params_wrapper.rb
@@ -135,7 +135,7 @@ module ActionController
         #
         # This method also does namespace lookup. Foo::Bar::UsersController will
         # try to find Foo::Bar::User, Foo::User and finally User.
-        def _default_wrap_model #:nodoc:
+        def _default_wrap_model
           return nil if klass.anonymous?
           model_name = klass.name.sub(/Controller$/, "").classify
 
@@ -205,7 +205,7 @@ module ActionController
           model = name_or_model_or_options
         end
 
-        opts   = Options.from_hash _wrapper_options.to_h.slice(:format).merge(options)
+        opts = Options.from_hash _wrapper_options.to_h.slice(:format).merge(options)
         opts.model = model
         opts.klass = self
 
diff --git a/actionpack/lib/action_controller/metal/redirecting.rb b/actionpack/lib/action_controller/metal/redirecting.rb
index 2b060e3698..30798c1d99 100644
--- a/actionpack/lib/action_controller/metal/redirecting.rb
+++ b/actionpack/lib/action_controller/metal/redirecting.rb
@@ -1,12 +1,4 @@
 module ActionController
-  class RedirectBackError < AbstractController::Error #:nodoc:
-    DEFAULT_MESSAGE = 'No HTTP_REFERER was set in the request to this action, so redirect_to :back could not be called successfully. If this is a test, make sure to specify request.env["HTTP_REFERER"].'
-
-    def initialize(message = nil)
-      super(message || DEFAULT_MESSAGE)
-    end
-  end
-
   module Redirecting
     extend ActiveSupport::Concern
 
diff --git a/actionpack/lib/action_controller/metal/renderers.rb b/actionpack/lib/action_controller/metal/renderers.rb
index f8a037189c..733aca195d 100644
--- a/actionpack/lib/action_controller/metal/renderers.rb
+++ b/actionpack/lib/action_controller/metal/renderers.rb
@@ -104,7 +104,7 @@ module ActionController
       #
       # Since <tt>ActionController::Metal</tt> controllers cannot render, the controller
       # must include <tt>AbstractController::Rendering</tt>, <tt>ActionController::Rendering</tt>,
-      # and <tt>ActionController::Renderers</tt>, and have at lest one renderer.
+      # and <tt>ActionController::Renderers</tt>, and have at least one renderer.
       #
       # Rather than including <tt>ActionController::Renderers::All</tt> and including all renderers,
       # you may specify which renderers to include by passing the renderer name or names to
diff --git a/actionpack/lib/action_controller/metal/rendering.rb b/actionpack/lib/action_controller/metal/rendering.rb
index 67365a143e..cdd09e832b 100644
--- a/actionpack/lib/action_controller/metal/rendering.rb
+++ b/actionpack/lib/action_controller/metal/rendering.rb
@@ -67,20 +67,20 @@ module ActionController
       end
 
       def _set_rendered_content_type(format)
-        unless response.content_type
+        if format && !response.content_type
           self.content_type = format.to_s
         end
       end
 
       # Normalize arguments by catching blocks and setting them on :update.
-      def _normalize_args(action=nil, options={}, &blk) #:nodoc:
+      def _normalize_args(action = nil, options = {}, &blk)
         options = super
         options[:update] = blk if block_given?
         options
       end
 
       # Normalize both text and status options.
-      def _normalize_options(options) #:nodoc:
+      def _normalize_options(options)
         _normalize_text(options)
 
         if options[:html]
@@ -103,7 +103,7 @@ module ActionController
       end
 
       # Process controller specific options, as status, content-type and location.
-      def _process_options(options) #:nodoc:
+      def _process_options(options)
         status, content_type, location = options.values_at(:status, :content_type, :location)
 
         self.status = status if status
diff --git a/actionpack/lib/action_controller/metal/request_forgery_protection.rb b/actionpack/lib/action_controller/metal/request_forgery_protection.rb
index 3d3c121280..e8965a6561 100644
--- a/actionpack/lib/action_controller/metal/request_forgery_protection.rb
+++ b/actionpack/lib/action_controller/metal/request_forgery_protection.rb
@@ -152,7 +152,7 @@ module ActionController #:nodoc:
           request.cookie_jar = NullCookieJar.build(request, {})
         end
 
-        protected
+        private
 
           class NullSessionHash < Rack::Session::Abstract::SessionHash #:nodoc:
             def initialize(req)
@@ -197,7 +197,7 @@ module ActionController #:nodoc:
       end
     end
 
-    protected
+    private
       # The actual before_action that is used to verify the CSRF token.
       # Don't override this directly. Provide your own forgery protection
       # strategy instead. If you override, you'll disable same-origin
@@ -208,7 +208,7 @@ module ActionController #:nodoc:
       # enabled on an action, this before_action flags its after_action to
       # verify that JavaScript responses are for XHR requests, ensuring they
       # follow the browser's same-origin policy.
-      def verify_authenticity_token
+      def verify_authenticity_token # :doc:
         mark_for_same_origin_verification!
 
         if !verified_request?
@@ -219,7 +219,7 @@ module ActionController #:nodoc:
         end
       end
 
-      def handle_unverified_request
+      def handle_unverified_request # :doc:
         forgery_protection_strategy.new(self).handle_unverified_request
       end
 
@@ -233,7 +233,7 @@ module ActionController #:nodoc:
       # If `verify_authenticity_token` was run (indicating that we have
       # forgery protection enabled for this request) then also verify that
       # we aren't serving an unauthorized cross-origin response.
-      def verify_same_origin_request
+      def verify_same_origin_request # :doc:
         if marked_for_same_origin_verification? && non_xhr_javascript_response?
           if logger && log_warning_on_csrf_failure
             logger.warn CROSS_ORIGIN_JAVASCRIPT_WARNING
@@ -243,18 +243,18 @@ module ActionController #:nodoc:
       end
 
       # GET requests are checked for cross-origin JavaScript after rendering.
-      def mark_for_same_origin_verification!
+      def mark_for_same_origin_verification! # :doc:
         @marked_for_same_origin_verification = request.get?
       end
 
       # If the `verify_authenticity_token` before_action ran, verify that
       # JavaScript responses are only served to same-origin GET requests.
-      def marked_for_same_origin_verification?
+      def marked_for_same_origin_verification? # :doc:
         @marked_for_same_origin_verification ||= false
       end
 
       # Check for cross-origin JavaScript responses.
-      def non_xhr_javascript_response?
+      def non_xhr_javascript_response? # :doc:
         content_type =~ %r(\Atext/javascript) && !request.xhr?
       end
 
@@ -265,20 +265,20 @@ module ActionController #:nodoc:
       # * Is it a GET or HEAD request?  Gets should be safe and idempotent
       # * Does the form_authenticity_token match the given token value from the params?
       # * Does the X-CSRF-Token header match the form_authenticity_token
-      def verified_request?
+      def verified_request? # :doc:
         !protect_against_forgery? || request.get? || request.head? ||
           (valid_request_origin? && any_authenticity_token_valid?)
       end
 
       # Checks if any of the authenticity tokens from the request are valid.
-      def any_authenticity_token_valid?
+      def any_authenticity_token_valid? # :doc:
         request_authenticity_tokens.any? do |token|
           valid_authenticity_token?(session, token)
         end
       end
 
       # Possible authenticity tokens sent in the request.
-      def request_authenticity_tokens
+      def request_authenticity_tokens # :doc:
         [form_authenticity_param, request.x_csrf_token]
       end
 
@@ -290,7 +290,7 @@ module ActionController #:nodoc:
       # Creates a masked version of the authenticity token that varies
       # on each request. The masking is used to mitigate SSL attacks
       # like BREACH.
-      def masked_authenticity_token(session, form_options: {})
+      def masked_authenticity_token(session, form_options: {}) # :doc:
         action, method = form_options.values_at(:action, :method)
 
         raw_token = if per_form_csrf_tokens && action && method
@@ -309,7 +309,7 @@ module ActionController #:nodoc:
       # Checks the client's masked token to see if it matches the
       # session token. Essentially the inverse of
       # +masked_authenticity_token+.
-      def valid_authenticity_token?(session, encoded_masked_token)
+      def valid_authenticity_token?(session, encoded_masked_token) # :doc:
         if encoded_masked_token.nil? || encoded_masked_token.empty? || !encoded_masked_token.is_a?(String)
           return false
         end
@@ -340,7 +340,7 @@ module ActionController #:nodoc:
         end
       end
 
-      def unmask_token(masked_token)
+      def unmask_token(masked_token) # :doc:
         # Split the token into the one-time pad and the encrypted
         # value and decrypt it
         one_time_pad = masked_token[0...AUTHENTICITY_TOKEN_LENGTH]
@@ -348,11 +348,11 @@ module ActionController #:nodoc:
         xor_byte_strings(one_time_pad, encrypted_csrf_token)
       end
 
-      def compare_with_real_token(token, session)
+      def compare_with_real_token(token, session) # :doc:
         ActiveSupport::SecurityUtils.secure_compare(token, real_csrf_token(session))
       end
 
-      def valid_per_form_csrf_token?(token, session)
+      def valid_per_form_csrf_token?(token, session) # :doc:
         if per_form_csrf_tokens
           correct_token = per_form_csrf_token(
             session,
@@ -366,12 +366,12 @@ module ActionController #:nodoc:
         end
       end
 
-      def real_csrf_token(session)
+      def real_csrf_token(session) # :doc:
         session[:_csrf_token] ||= SecureRandom.base64(AUTHENTICITY_TOKEN_LENGTH)
         Base64.strict_decode64(session[:_csrf_token])
       end
 
-      def per_form_csrf_token(session, action_path, method)
+      def per_form_csrf_token(session, action_path, method) # :doc:
         OpenSSL::HMAC.digest(
           OpenSSL::Digest::SHA256.new,
           real_csrf_token(session),
@@ -379,25 +379,25 @@ module ActionController #:nodoc:
         )
       end
 
-      def xor_byte_strings(s1, s2)
+      def xor_byte_strings(s1, s2) # :doc:
         s2_bytes = s2.bytes
         s1.each_byte.with_index { |c1, i| s2_bytes[i] ^= c1 }
         s2_bytes.pack("C*")
       end
 
       # The form's authenticity parameter. Override to provide your own.
-      def form_authenticity_param
+      def form_authenticity_param # :doc:
         params[request_forgery_protection_token]
       end
 
       # Checks if the controller allows forgery protection.
-      def protect_against_forgery?
+      def protect_against_forgery? # :doc:
         allow_forgery_protection
       end
 
       # Checks if the request originated from the same origin by looking at the
       # Origin header.
-      def valid_request_origin?
+      def valid_request_origin? # :doc:
         if forgery_protection_origin_check
           # We accept blank origin headers because some user agents don't send it.
           request.origin.nil? || request.origin == request.base_url
@@ -406,7 +406,7 @@ module ActionController #:nodoc:
         end
       end
 
-      def normalize_action_path(action_path)
+      def normalize_action_path(action_path) # :doc:
         uri = URI.parse(action_path)
         uri.path.chomp("/")
       end
diff --git a/actionpack/lib/action_controller/metal/streaming.rb b/actionpack/lib/action_controller/metal/streaming.rb
index 481f19f1ef..877a08b222 100644
--- a/actionpack/lib/action_controller/metal/streaming.rb
+++ b/actionpack/lib/action_controller/metal/streaming.rb
@@ -193,10 +193,10 @@ module ActionController #:nodoc:
   module Streaming
     extend ActiveSupport::Concern
 
-    protected
+    private
 
       # Set proper cache control and transfer encoding when streaming
-      def _process_options(options) #:nodoc:
+      def _process_options(options)
         super
         if options[:stream]
           if request.version == "HTTP/1.0"
@@ -210,7 +210,7 @@ module ActionController #:nodoc:
       end
 
       # Call render_body if we are streaming instead of usual +render+.
-      def _render_template(options) #:nodoc:
+      def _render_template(options)
         if options.delete(:stream)
           Rack::Chunked::Body.new view_renderer.render_body(view_context, options)
         else
diff --git a/actionpack/lib/action_controller/metal/strong_parameters.rb b/actionpack/lib/action_controller/metal/strong_parameters.rb
index b64617d084..acfeca1fcb 100644
--- a/actionpack/lib/action_controller/metal/strong_parameters.rb
+++ b/actionpack/lib/action_controller/metal/strong_parameters.rb
@@ -71,8 +71,8 @@ module ActionController
   # * +permit_all_parameters+ - If it's +true+, all the parameters will be
   #   permitted by default. The default is +false+.
   # * +action_on_unpermitted_parameters+ - Allow to control the behavior when parameters
-  #   that are not explicitly permitted are found. The values can be <tt>:log</tt> to
-  #   write a message on the logger or <tt>:raise</tt> to raise
+  #   that are not explicitly permitted are found. The values can be +false+ to just filter them
+  #   out, <tt>:log</tt> to additionally write a message on the logger, or <tt>:raise</tt> to raise
   #   ActionController::UnpermittedParameters exception. The default value is <tt>:log</tt>
   #   in test and development environments, +false+ otherwise.
   #
@@ -334,6 +334,15 @@ module ActionController
     #   params = ActionController::Parameters.new(tags: ['rails', 'parameters'])
     #   params.permit(tags: [])
     #
+    # Sometimes it is not possible or convenient to declare the valid keys of
+    # a hash parameter or its internal structure. Just map to an empty hash:
+    #
+    #   params.permit(preferences: {})
+    #
+    # but be careful because this opens the door to arbitrary input. In this
+    # case, +permit+ ensures values in the returned structure are permitted
+    # scalars and filters out anything else.
+    #
     # You can also use +permit+ on nested parameters, like:
     #
     #   params = ActionController::Parameters.new({
@@ -382,14 +391,15 @@ module ActionController
         case filter
         when Symbol, String
           permitted_scalar_filter(params, filter)
-        when Hash then
+        when Hash
           hash_filter(params, filter)
         end
       end
 
       unpermitted_parameters!(params) if self.class.action_on_unpermitted_parameters
 
-      params.permit!
+      params.permitted = true
+      params
     end
 
     # Returns a parameter for the given +key+. If not found,
@@ -539,7 +549,7 @@ module ActionController
       new_instance_with_inherited_permitted_status(@parameters.select(&block))
     end
 
-    # Equivalent to Hash#keep_if, but returns nil if no changes were made.
+    # Equivalent to Hash#keep_if, but returns +nil+ if no changes were made.
     def select!(&block)
       @parameters.select!(&block)
       self
@@ -573,6 +583,13 @@ module ActionController
       )
     end
 
+    # Returns current <tt>ActionController::Parameters</tt> instance which
+    # +other_hash+ merges into current hash.
+    def merge!(other_hash)
+      @parameters.merge!(other_hash.to_h)
+      self
+    end
+
     # This is required by ActiveModel attribute assignment, so that user can
     # pass +Parameters+ to a mass assignment methods in a model. It should not
     # matter as we are using +HashWithIndifferentAccess+ internally.
@@ -680,7 +697,7 @@ module ActionController
         when Parameters
           if object.fields_for_style?
             hash = object.class.new
-            object.each { |k,v| hash[k] = yield v }
+            object.each { |k, v| hash[k] = yield v }
             hash
           else
             yield object
@@ -759,6 +776,7 @@ module ActionController
       end
 
       EMPTY_ARRAY = []
+      EMPTY_HASH  = {}
       def hash_filter(params, filter)
         filter = filter.with_indifferent_access
 
@@ -772,6 +790,11 @@ module ActionController
             array_of_permitted_scalars?(self[key]) do |val|
               params[key] = val
             end
+          elsif filter[key] == EMPTY_HASH
+            # Declaration { preferences: {} }.
+            if value.is_a?(Parameters)
+              params[key] = permit_any_in_parameters(value)
+            end
           elsif non_scalar?(value)
             # Declaration { user: :name } or { user: [:name, :age, { address: ... }] }.
             params[key] = each_element(value) do |element|
@@ -781,6 +804,39 @@ module ActionController
         end
       end
 
+      def permit_any_in_parameters(params)
+        self.class.new.tap do |sanitized|
+          params.each do |key, value|
+            case value
+            when ->(v) { permitted_scalar?(v) }
+              sanitized[key] = value
+            when Array
+              sanitized[key] = permit_any_in_array(value)
+            when Parameters
+              sanitized[key] = permit_any_in_parameters(value)
+            else
+              # Filter this one out.
+            end
+          end
+          sanitized.permitted = true
+        end
+      end
+
+      def permit_any_in_array(array)
+        [].tap do |sanitized|
+          array.each do |element|
+            case element
+            when ->(e) { permitted_scalar?(e) }
+              sanitized << element
+            when Parameters
+              sanitized << permit_any_in_parameters(element)
+            else
+              # Filter this one out.
+            end
+          end
+        end
+      end
+
       def initialize_copy(source)
         super
         @parameters = @parameters.dup
diff --git a/actionpack/lib/action_controller/railtie.rb b/actionpack/lib/action_controller/railtie.rb
index 6513a556ee..a7cdfe6a98 100644
--- a/actionpack/lib/action_controller/railtie.rb
+++ b/actionpack/lib/action_controller/railtie.rb
@@ -51,7 +51,7 @@ module ActionController
         extend ::AbstractController::Railties::RoutesHelpers.with(app.routes)
         extend ::ActionController::Railties::Helpers
 
-        options.each do |k,v|
+        options.each do |k, v|
           k = "#{k}="
           if respond_to?(k)
             send(k, v)
diff --git a/actionpack/lib/action_controller/renderer.rb b/actionpack/lib/action_controller/renderer.rb
index 0739f16965..3ff80e6a39 100644
--- a/actionpack/lib/action_controller/renderer.rb
+++ b/actionpack/lib/action_controller/renderer.rb
@@ -83,7 +83,7 @@ module ActionController
     private
       def normalize_keys(env)
         new_env = {}
-        env.each_pair { |k,v| new_env[rack_key_for(k)] = rack_value_for(k, v) }
+        env.each_pair { |k, v| new_env[rack_key_for(k)] = rack_value_for(k, v) }
         new_env
       end
 
@@ -102,7 +102,9 @@ module ActionController
         method: ->(v) { v.upcase },
       }
 
-      def rack_key_for(key); RACK_KEY_TRANSLATION[key]; end
+      def rack_key_for(key)
+        RACK_KEY_TRANSLATION.fetch(key, key.to_s)
+      end
 
       def rack_value_for(key, value)
         RACK_VALUE_TRANSLATION.fetch(key, IDENTITY).call value
diff --git a/actionpack/lib/action_controller/test_case.rb b/actionpack/lib/action_controller/test_case.rb
index 33c0201951..441667e556 100644
--- a/actionpack/lib/action_controller/test_case.rb
+++ b/actionpack/lib/action_controller/test_case.rb
@@ -3,6 +3,7 @@ require "active_support/core_ext/hash/conversions"
 require "active_support/core_ext/object/to_query"
 require "active_support/core_ext/module/anonymous"
 require "active_support/core_ext/hash/keys"
+require "active_support/testing/constant_lookup"
 require "action_controller/template_assertions"
 require "rails-dom-testing"
 
@@ -112,8 +113,9 @@ module ActionController
           end
         end
 
-        set_header "CONTENT_LENGTH", data.length.to_s
-        set_header "rack.input", StringIO.new(data)
+        data_stream = StringIO.new(data)
+        set_header "CONTENT_LENGTH", data_stream.length.to_s
+        set_header "rack.input", data_stream
       end
 
       fetch_header("PATH_INFO") do |k|
@@ -513,8 +515,6 @@ module ActionController
           @request = @controller.request
           @response = @controller.response
 
-          @request.delete_header "HTTP_COOKIE"
-
           if @request.have_cookie_jar?
             unless @request.cookie_jar.committed?
               @request.cookie_jar.write(@response)
diff --git a/actionpack/lib/action_dispatch/http/filter_parameters.rb b/actionpack/lib/action_dispatch/http/filter_parameters.rb
index e5874a39f6..e584b84d92 100644
--- a/actionpack/lib/action_dispatch/http/filter_parameters.rb
+++ b/actionpack/lib/action_dispatch/http/filter_parameters.rb
@@ -51,28 +51,28 @@ module ActionDispatch
         @filtered_path ||= query_string.empty? ? path : "#{path}?#{filtered_query_string}"
       end
 
-    protected
+    private
 
-      def parameter_filter
+      def parameter_filter # :doc:
         parameter_filter_for fetch_header("action_dispatch.parameter_filter") {
           return NULL_PARAM_FILTER
         }
       end
 
-      def env_filter
+      def env_filter # :doc:
         user_key = fetch_header("action_dispatch.parameter_filter") {
           return NULL_ENV_FILTER
         }
         parameter_filter_for(Array(user_key) + ENV_MATCH)
       end
 
-      def parameter_filter_for(filters)
+      def parameter_filter_for(filters) # :doc:
         ParameterFilter.new(filters)
       end
 
       KV_RE   = "[^&;=]+"
       PAIR_RE = %r{(#{KV_RE})=(#{KV_RE})}
-      def filtered_query_string
+      def filtered_query_string # :doc:
         query_string.gsub(PAIR_RE) do |_|
           parameter_filter.filter([[$1, $2]]).first.join("=")
         end
diff --git a/actionpack/lib/action_dispatch/http/mime_negotiation.rb b/actionpack/lib/action_dispatch/http/mime_negotiation.rb
index d0c9413efa..c4fe3a5c09 100644
--- a/actionpack/lib/action_dispatch/http/mime_negotiation.rb
+++ b/actionpack/lib/action_dispatch/http/mime_negotiation.rb
@@ -29,8 +29,8 @@ module ActionDispatch
         content_mime_type && content_mime_type.to_s
       end
 
-      def has_content_type?
-        has_header? "CONTENT_TYPE"
+      def has_content_type? # :nodoc:
+        get_header "CONTENT_TYPE"
       end
 
       # Returns the accepted MIME type for the request.
@@ -150,20 +150,20 @@ module ActionDispatch
         order.include?(Mime::ALL) ? format : nil
       end
 
-      protected
+      private
 
         BROWSER_LIKE_ACCEPTS = /,\s*\*\/\*|\*\/\*\s*,/
 
-        def valid_accept_header
+        def valid_accept_header # :doc:
           (xhr? && (accept.present? || content_mime_type)) ||
             (accept.present? && accept !~ BROWSER_LIKE_ACCEPTS)
         end
 
-        def use_accept_header
+        def use_accept_header # :doc:
           !self.class.ignore_accept_header
         end
 
-        def format_from_path_extension
+        def format_from_path_extension # :doc:
           path = get_header("action_dispatch.original_path") || get_header("PATH_INFO")
           if match = path && path.match(/\.(\w+)\z/)
             Mime[match.captures.first]
diff --git a/actionpack/lib/action_dispatch/http/mime_type.rb b/actionpack/lib/action_dispatch/http/mime_type.rb
index 58eb8d0baf..6b718e3682 100644
--- a/actionpack/lib/action_dispatch/http/mime_type.rb
+++ b/actionpack/lib/action_dispatch/http/mime_type.rb
@@ -278,6 +278,8 @@ module Mime
 
     def all?; false; end
 
+    # TODO Change this to private once we've dropped Ruby 2.2 support.
+    # Workaround for Ruby 2.2 "private attribute?" warning.
     protected
 
       attr_reader :string, :synonyms
@@ -295,7 +297,7 @@ module Mime
         end
       end
 
-      def respond_to_missing?(method, include_private = false) #:nodoc:
+      def respond_to_missing?(method, include_private = false)
         method.to_s.ends_with? "?"
       end
   end
diff --git a/actionpack/lib/action_dispatch/http/parameter_filter.rb b/actionpack/lib/action_dispatch/http/parameter_filter.rb
index 01fe35f5c6..889f55a52a 100644
--- a/actionpack/lib/action_dispatch/http/parameter_filter.rb
+++ b/actionpack/lib/action_dispatch/http/parameter_filter.rb
@@ -50,7 +50,7 @@ module ActionDispatch
         def initialize(regexps, deep_regexps, blocks)
           @regexps = regexps
           @deep_regexps = deep_regexps.any? ? deep_regexps : nil
-          @blocks  = blocks
+          @blocks = blocks
         end
 
         def call(original_params, parents = [])
diff --git a/actionpack/lib/action_dispatch/http/parameters.rb b/actionpack/lib/action_dispatch/http/parameters.rb
index ddd15b748b..ad4aadacf5 100644
--- a/actionpack/lib/action_dispatch/http/parameters.rb
+++ b/actionpack/lib/action_dispatch/http/parameters.rb
@@ -45,7 +45,7 @@ module ActionDispatch
                    query_parameters.dup
                  end
         params.merge!(path_parameters)
-        params = set_custom_encoding(params)
+        params = set_binary_encoding(params)
         set_header("action_dispatch.request.parameters", params)
         params
       end
@@ -73,21 +73,16 @@ module ActionDispatch
 
       private
 
-        def set_custom_encoding(params)
+        def set_binary_encoding(params)
           action = params[:action]
-          params.each do |k, v|
-            if v.is_a?(String) && v.encoding != encoding_template(action, k)
-              params[k] = v.force_encoding(encoding_template(action, k))
+          if controller_class.binary_params_for?(action)
+            ActionDispatch::Request::Utils.each_param_value(params) do |param|
+              param.force_encoding ::Encoding::ASCII_8BIT
             end
           end
-
           params
         end
 
-        def encoding_template(action, param)
-          controller_class.encoding_for_param(action, param)
-        end
-
         def parse_formatted_parameters(parsers)
           return yield if content_length.zero? || content_mime_type.nil?
 
diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index 9986d6e1e9..a886358399 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -69,7 +69,7 @@ module ActionDispatch
     PASS_NOT_FOUND = Class.new { # :nodoc:
       def self.action(_); self; end
       def self.call(_); [404, { "X-Cascade" => "pass" }, []]; end
-      def self.encoding_for_param(action, param); ::Encoding::UTF_8; end
+      def self.binary_params_for?(action); false; end
     }
 
     def controller_class
diff --git a/actionpack/lib/action_dispatch/http/response.rb b/actionpack/lib/action_dispatch/http/response.rb
index e8173e2a99..516a2af69a 100644
--- a/actionpack/lib/action_dispatch/http/response.rb
+++ b/actionpack/lib/action_dispatch/http/response.rb
@@ -39,7 +39,7 @@ module ActionDispatch # :nodoc:
         super(header)
       end
 
-      def []=(k,v)
+      def []=(k, v)
         if @response.sending? || @response.sent?
           raise ActionDispatch::IllegalStateError, "header already sent"
         end
@@ -227,7 +227,9 @@ module ActionDispatch # :nodoc:
       return unless content_type
       new_header_info = parse_content_type(content_type.to_s)
       prev_header_info = parsed_content_type_header
-      set_content_type new_header_info.mime_type, new_header_info.charset || prev_header_info.charset || self.class.default_charset
+      charset = new_header_info.charset || prev_header_info.charset
+      charset ||= self.class.default_charset unless prev_header_info.mime_type
+      set_content_type new_header_info.mime_type, charset
     end
 
     # Sets the HTTP response's content MIME type. For example, in the controller
@@ -249,7 +251,7 @@ module ActionDispatch # :nodoc:
       end
     end
 
-    # Sets the HTTP character set. In case of nil parameter
+    # Sets the HTTP character set. In case of +nil+ parameter
     # it sets the charset to utf-8.
     #
     #   response.charset = 'utf-16' # => 'utf-16'
@@ -408,7 +410,7 @@ module ActionDispatch # :nodoc:
     def parse_content_type(content_type)
       if content_type
         type, charset = content_type.split(/;\s*charset=/)
-        type = nil if type.empty?
+        type = nil if type && type.empty?
         ContentTypeHeader.new(type, charset)
       else
         NullContentTypeHeader
diff --git a/actionpack/lib/action_dispatch/http/upload.rb b/actionpack/lib/action_dispatch/http/upload.rb
index 9aa73c862b..61ba052e45 100644
--- a/actionpack/lib/action_dispatch/http/upload.rb
+++ b/actionpack/lib/action_dispatch/http/upload.rb
@@ -24,7 +24,7 @@ module ActionDispatch
       attr_accessor :headers
 
       def initialize(hash) # :nodoc:
-        @tempfile          = hash[:tempfile]
+        @tempfile = hash[:tempfile]
         raise(ArgumentError, ":tempfile is required") unless @tempfile
 
         @original_filename = hash[:filename]
@@ -40,7 +40,7 @@ module ActionDispatch
       end
 
       # Shortcut for +tempfile.read+.
-      def read(length=nil, buffer=nil)
+      def read(length = nil, buffer = nil)
         @tempfile.read(length, buffer)
       end
 
@@ -50,7 +50,7 @@ module ActionDispatch
       end
 
       # Shortcut for +tempfile.close+.
-      def close(unlink_now=false)
+      def close(unlink_now = false)
         @tempfile.close(unlink_now)
       end
 
diff --git a/actionpack/lib/action_dispatch/http/url.rb b/actionpack/lib/action_dispatch/http/url.rb
index 06ffa983d1..a6937d54ff 100644
--- a/actionpack/lib/action_dispatch/http/url.rb
+++ b/actionpack/lib/action_dispatch/http/url.rb
@@ -66,7 +66,7 @@ module ActionDispatch
         end
 
         def path_for(options)
-          path  = options[:script_name].to_s.chomp("/".freeze)
+          path = options[:script_name].to_s.chomp("/".freeze)
           path << options[:path] if options.key?(:path)
 
           add_trailing_slash(path) if options[:trailing_slash]
@@ -80,7 +80,7 @@ module ActionDispatch
 
         def add_params(path, params)
           params = { params: params } unless params.is_a?(Hash)
-          params.reject! { |_,v| v.to_param.nil? }
+          params.reject! { |_, v| v.to_param.nil? }
           query = params.to_query
           path << "?#{query}" unless query.empty?
         end
diff --git a/actionpack/lib/action_dispatch/journey/formatter.rb b/actionpack/lib/action_dispatch/journey/formatter.rb
index dc8b24b089..1d239addf8 100644
--- a/actionpack/lib/action_dispatch/journey/formatter.rb
+++ b/actionpack/lib/action_dispatch/journey/formatter.rb
@@ -1,10 +1,11 @@
 require "action_controller/metal/exceptions"
 
 module ActionDispatch
+  # :stopdoc:
   module Journey
     # The Formatter class is used for formatting URLs. For example, parameters
     # passed to +url_for+ in Rails will eventually call Formatter#generate.
-    class Formatter # :nodoc:
+    class Formatter
       attr_reader :routes
 
       def initialize(routes)
@@ -47,7 +48,7 @@ module ActionDispatch
         unmatched_keys = (missing_keys || []) & constraints.keys
         missing_keys = (missing_keys || []) - unmatched_keys
 
-        message = "No route matches #{Hash[constraints.sort_by { |k,v| k.to_s }].inspect}"
+        message = "No route matches #{Hash[constraints.sort_by { |k, v| k.to_s }].inspect}"
         message << ", missing required keys: #{missing_keys.sort.inspect}" if missing_keys && !missing_keys.empty?
         message << ", possible unmatched constraints: #{unmatched_keys.sort.inspect}" if unmatched_keys && !unmatched_keys.empty?
 
@@ -91,7 +92,11 @@ module ActionDispatch
           else
             routes = non_recursive(cache, options)
 
-            hash = routes.group_by { |_, r| r.score(options) }
+            supplied_keys = options.each_with_object({}) do |(k, v), h|
+              h[k.to_s] = true if v
+            end
+
+            hash = routes.group_by { |_, r| r.score(supplied_keys) }
 
             hash.keys.sort.reverse_each do |score|
               break if score < 0
@@ -178,4 +183,5 @@ module ActionDispatch
         end
     end
   end
+  # :startdoc:
 end
diff --git a/actionpack/lib/action_dispatch/journey/gtg/builder.rb b/actionpack/lib/action_dispatch/journey/gtg/builder.rb
index 9990c66627..0f8bed89bf 100644
--- a/actionpack/lib/action_dispatch/journey/gtg/builder.rb
+++ b/actionpack/lib/action_dispatch/journey/gtg/builder.rb
@@ -17,7 +17,7 @@ module ActionDispatch
         def transition_table
           dtrans   = TransitionTable.new
           marked   = {}
-          state_id = Hash.new { |h,k| h[k] = h.length }
+          state_id = Hash.new { |h, k| h[k] = h.length }
 
           start   = firstpos(root)
           dstates = [start]
diff --git a/actionpack/lib/action_dispatch/journey/gtg/transition_table.rb b/actionpack/lib/action_dispatch/journey/gtg/transition_table.rb
index 0be18dc26f..beb9f1ef3b 100644
--- a/actionpack/lib/action_dispatch/journey/gtg/transition_table.rb
+++ b/actionpack/lib/action_dispatch/journey/gtg/transition_table.rb
@@ -12,7 +12,7 @@ module ActionDispatch
           @regexp_states = {}
           @string_states = {}
           @accepting     = {}
-          @memos         = Hash.new { |h,k| h[k] = [] }
+          @memos         = Hash.new { |h, k| h[k] = [] }
         end
 
         def add_accepting(state)
@@ -56,7 +56,7 @@ module ActionDispatch
         end
 
         def as_json(options = nil)
-          simple_regexp = Hash.new { |h,k| h[k] = {} }
+          simple_regexp = Hash.new { |h, k| h[k] = {} }
 
           @regexp_states.each do |from, hash|
             hash.each do |re, to|
diff --git a/actionpack/lib/action_dispatch/journey/nfa/builder.rb b/actionpack/lib/action_dispatch/journey/nfa/builder.rb
index 19e5752ae5..532f765094 100644
--- a/actionpack/lib/action_dispatch/journey/nfa/builder.rb
+++ b/actionpack/lib/action_dispatch/journey/nfa/builder.rb
@@ -36,7 +36,7 @@ module ActionDispatch
         def visit_OR(node)
           from = @i += 1
           children = node.children.map { |c| visit(c) }
-          to   = @i += 1
+          to = @i += 1
 
           children.each do |child|
             @tt[from, child.first] = nil
diff --git a/actionpack/lib/action_dispatch/journey/nfa/transition_table.rb b/actionpack/lib/action_dispatch/journey/nfa/transition_table.rb
index 4737adc724..543a670da0 100644
--- a/actionpack/lib/action_dispatch/journey/nfa/transition_table.rb
+++ b/actionpack/lib/action_dispatch/journey/nfa/transition_table.rb
@@ -10,7 +10,7 @@ module ActionDispatch
         attr_reader :memos
 
         def initialize
-          @table     = Hash.new { |h,f| h[f] = {} }
+          @table     = Hash.new { |h, f| h[f] = {} }
           @memos     = {}
           @accepting = nil
           @inverted  = nil
diff --git a/actionpack/lib/action_dispatch/journey/parser.rb b/actionpack/lib/action_dispatch/journey/parser.rb
index 01ff2109cb..db42b64c4b 100644
--- a/actionpack/lib/action_dispatch/journey/parser.rb
+++ b/actionpack/lib/action_dispatch/journey/parser.rb
@@ -1,196 +1,199 @@
 #
 # DO NOT MODIFY!!!!
-# This file is automatically generated by Racc 1.4.11
+# This file is automatically generated by Racc 1.4.14
 # from Racc grammer file "".
 #
 
-require "racc/parser.rb"
+require 'racc/parser.rb'
+
+# :stopdoc:
 
 require "action_dispatch/journey/parser_extras"
 module ActionDispatch
   module Journey
     class Parser < Racc::Parser
-      ##### State transition tables begin ###
-
-      racc_action_table = [
-          13,    15,    14,     7,    21,    16,     8,    19,    13,    15,
-          14,     7,    17,    16,     8,    13,    15,    14,     7,    24,
-          16,     8,    13,    15,    14,     7,    19,    16,     8 ]
-
-      racc_action_check = [
-           2,     2,     2,     2,    17,     2,     2,     2,     0,     0,
-           0,     0,     1,     0,     0,    19,    19,    19,    19,    20,
-          19,    19,     7,     7,     7,     7,    22,     7,     7 ]
-
-      racc_action_pointer = [
-           6,    12,    -2,   nil,   nil,   nil,   nil,    20,   nil,   nil,
-         nil,   nil,   nil,   nil,   nil,   nil,   nil,     4,   nil,    13,
-          13,   nil,    17,   nil,   nil ]
-
-      racc_action_default = [
-         -19,   -19,    -2,    -3,    -4,    -5,    -6,   -19,   -10,   -11,
-         -12,   -13,   -14,   -15,   -16,   -17,   -18,   -19,    -1,   -19,
-         -19,    25,    -8,    -9,    -7 ]
-
-      racc_goto_table = [
-           1,    22,    18,    23,   nil,   nil,   nil,    20 ]
-
-      racc_goto_check = [
-           1,     2,     1,     3,   nil,   nil,   nil,     1 ]
-
-      racc_goto_pointer = [
-         nil,     0,   -18,   -16,   nil,   nil,   nil,   nil,   nil,   nil,
-         nil ]
-
-      racc_goto_default = [
-         nil,   nil,     2,     3,     4,     5,     6,     9,    10,    11,
-          12 ]
-
-      racc_reduce_table = [
-        0, 0, :racc_error,
-        2, 11, :_reduce_1,
-        1, 11, :_reduce_2,
-        1, 11, :_reduce_none,
-        1, 12, :_reduce_none,
-        1, 12, :_reduce_none,
-        1, 12, :_reduce_none,
-        3, 15, :_reduce_7,
-        3, 13, :_reduce_8,
-        3, 13, :_reduce_9,
-        1, 16, :_reduce_10,
-        1, 14, :_reduce_none,
-        1, 14, :_reduce_none,
-        1, 14, :_reduce_none,
-        1, 14, :_reduce_none,
-        1, 19, :_reduce_15,
-        1, 17, :_reduce_16,
-        1, 18, :_reduce_17,
-        1, 20, :_reduce_18 ]
-
-      racc_reduce_n = 19
-
-      racc_shift_n = 25
-
-      racc_token_table = {
-        false => 0,
-        :error => 1,
-        :SLASH => 2,
-        :LITERAL => 3,
-        :SYMBOL => 4,
-        :LPAREN => 5,
-        :RPAREN => 6,
-        :DOT => 7,
-        :STAR => 8,
-        :OR => 9 }
-
-      racc_nt_base = 10
-
-      racc_use_result_var = false
-
-      Racc_arg = [
-        racc_action_table,
-        racc_action_check,
-        racc_action_default,
-        racc_action_pointer,
-        racc_goto_table,
-        racc_goto_check,
-        racc_goto_default,
-        racc_goto_pointer,
-        racc_nt_base,
-        racc_reduce_table,
-        racc_token_table,
-        racc_shift_n,
-        racc_reduce_n,
-        racc_use_result_var ]
-
-      Racc_token_to_s_table = [
-        "$end",
-        "error",
-        "SLASH",
-        "LITERAL",
-        "SYMBOL",
-        "LPAREN",
-        "RPAREN",
-        "DOT",
-        "STAR",
-        "OR",
-        "$start",
-        "expressions",
-        "expression",
-        "or",
-        "terminal",
-        "group",
-        "star",
-        "symbol",
-        "literal",
-        "slash",
-        "dot" ]
-
-      Racc_debug_parser = false
-
-      ##### State transition tables end #####
-
-      # reduce 0 omitted
-
-      def _reduce_1(val, _values)
-        Cat.new(val.first, val.last)
-      end
-
-      def _reduce_2(val, _values)
-        val.first
-      end
-
-      # reduce 3 omitted
-
-      # reduce 4 omitted
-
-      # reduce 5 omitted
-
-      # reduce 6 omitted
-
-      def _reduce_7(val, _values)
-        Group.new(val[1])
-      end
-
-      def _reduce_8(val, _values)
-        Or.new([val.first, val.last])
-      end
-
-      def _reduce_9(val, _values)
-        Or.new([val.first, val.last])
-      end
-
-      def _reduce_10(val, _values)
-        Star.new(Symbol.new(val.last))
-      end
-
-      # reduce 11 omitted
-
-      # reduce 12 omitted
-
-      # reduce 13 omitted
-
-      # reduce 14 omitted
-
-      def _reduce_15(val, _values)
-        Slash.new("/")
-      end
-
-      def _reduce_16(val, _values)
-        Symbol.new(val.first)
-      end
-
-      def _reduce_17(val, _values)
-        Literal.new(val.first)
-      end
-
-      def _reduce_18(val, _values)
-        Dot.new(val.first)
-      end
-
-      def _reduce_none(val, _values)
-        val[0]
-      end
+##### State transition tables begin ###
+
+racc_action_table = [
+    13,    15,    14,     7,    19,    16,     8,    19,    13,    15,
+    14,     7,    17,    16,     8,    13,    15,    14,     7,    21,
+    16,     8,    13,    15,    14,     7,    24,    16,     8 ]
+
+racc_action_check = [
+     2,     2,     2,     2,    22,     2,     2,     2,    19,    19,
+    19,    19,     1,    19,    19,     7,     7,     7,     7,    17,
+     7,     7,     0,     0,     0,     0,    20,     0,     0 ]
+
+racc_action_pointer = [
+    20,    12,    -2,   nil,   nil,   nil,   nil,    13,   nil,   nil,
+   nil,   nil,   nil,   nil,   nil,   nil,   nil,    19,   nil,     6,
+    20,   nil,    -5,   nil,   nil ]
+
+racc_action_default = [
+   -19,   -19,    -2,    -3,    -4,    -5,    -6,   -19,   -10,   -11,
+   -12,   -13,   -14,   -15,   -16,   -17,   -18,   -19,    -1,   -19,
+   -19,    25,    -8,    -9,    -7 ]
+
+racc_goto_table = [
+     1,    22,    18,    23,   nil,   nil,   nil,    20 ]
+
+racc_goto_check = [
+     1,     2,     1,     3,   nil,   nil,   nil,     1 ]
+
+racc_goto_pointer = [
+   nil,     0,   -18,   -16,   nil,   nil,   nil,   nil,   nil,   nil,
+   nil ]
+
+racc_goto_default = [
+   nil,   nil,     2,     3,     4,     5,     6,     9,    10,    11,
+    12 ]
+
+racc_reduce_table = [
+  0, 0, :racc_error,
+  2, 11, :_reduce_1,
+  1, 11, :_reduce_2,
+  1, 11, :_reduce_none,
+  1, 12, :_reduce_none,
+  1, 12, :_reduce_none,
+  1, 12, :_reduce_none,
+  3, 15, :_reduce_7,
+  3, 13, :_reduce_8,
+  3, 13, :_reduce_9,
+  1, 16, :_reduce_10,
+  1, 14, :_reduce_none,
+  1, 14, :_reduce_none,
+  1, 14, :_reduce_none,
+  1, 14, :_reduce_none,
+  1, 19, :_reduce_15,
+  1, 17, :_reduce_16,
+  1, 18, :_reduce_17,
+  1, 20, :_reduce_18 ]
+
+racc_reduce_n = 19
+
+racc_shift_n = 25
+
+racc_token_table = {
+  false => 0,
+  :error => 1,
+  :SLASH => 2,
+  :LITERAL => 3,
+  :SYMBOL => 4,
+  :LPAREN => 5,
+  :RPAREN => 6,
+  :DOT => 7,
+  :STAR => 8,
+  :OR => 9 }
+
+racc_nt_base = 10
+
+racc_use_result_var = false
+
+Racc_arg = [
+  racc_action_table,
+  racc_action_check,
+  racc_action_default,
+  racc_action_pointer,
+  racc_goto_table,
+  racc_goto_check,
+  racc_goto_default,
+  racc_goto_pointer,
+  racc_nt_base,
+  racc_reduce_table,
+  racc_token_table,
+  racc_shift_n,
+  racc_reduce_n,
+  racc_use_result_var ]
+
+Racc_token_to_s_table = [
+  "$end",
+  "error",
+  "SLASH",
+  "LITERAL",
+  "SYMBOL",
+  "LPAREN",
+  "RPAREN",
+  "DOT",
+  "STAR",
+  "OR",
+  "$start",
+  "expressions",
+  "expression",
+  "or",
+  "terminal",
+  "group",
+  "star",
+  "symbol",
+  "literal",
+  "slash",
+  "dot" ]
+
+Racc_debug_parser = false
+
+##### State transition tables end #####
+
+# reduce 0 omitted
+
+def _reduce_1(val, _values)
+ Cat.new(val.first, val.last) 
+end
+
+def _reduce_2(val, _values)
+ val.first 
+end
+
+# reduce 3 omitted
+
+# reduce 4 omitted
+
+# reduce 5 omitted
+
+# reduce 6 omitted
+
+def _reduce_7(val, _values)
+ Group.new(val[1]) 
+end
+
+def _reduce_8(val, _values)
+ Or.new([val.first, val.last]) 
+end
+
+def _reduce_9(val, _values)
+ Or.new([val.first, val.last]) 
+end
+
+def _reduce_10(val, _values)
+ Star.new(Symbol.new(val.last)) 
+end
+
+# reduce 11 omitted
+
+# reduce 12 omitted
+
+# reduce 13 omitted
+
+# reduce 14 omitted
+
+def _reduce_15(val, _values)
+ Slash.new(val.first) 
+end
+
+def _reduce_16(val, _values)
+ Symbol.new(val.first) 
+end
+
+def _reduce_17(val, _values)
+ Literal.new(val.first) 
+end
+
+def _reduce_18(val, _values)
+ Dot.new(val.first) 
+end
+
+def _reduce_none(val, _values)
+  val[0]
+end
+
     end   # class Parser
-  end   # module Journey
-end   # module ActionDispatch
+    end   # module Journey
+  end   # module ActionDispatch
diff --git a/actionpack/lib/action_dispatch/journey/parser.y b/actionpack/lib/action_dispatch/journey/parser.y
index d3f7c4d765..f9b1a7a958 100644
--- a/actionpack/lib/action_dispatch/journey/parser.y
+++ b/actionpack/lib/action_dispatch/journey/parser.y
@@ -30,7 +30,7 @@ rule
     | dot
     ;
   slash
-    : SLASH              { Slash.new('/') }
+    : SLASH              { Slash.new(val.first) }
     ;
   symbol
     : SYMBOL             { Symbol.new(val.first) }
@@ -45,5 +45,6 @@ rule
 end
 
 ---- header
+# :stopdoc:
 
-require 'action_dispatch/journey/parser_extras'
+require "action_dispatch/journey/parser_extras"
diff --git a/actionpack/lib/action_dispatch/journey/parser_extras.rb b/actionpack/lib/action_dispatch/journey/parser_extras.rb
index ec26e634e8..4c7e82d93c 100644
--- a/actionpack/lib/action_dispatch/journey/parser_extras.rb
+++ b/actionpack/lib/action_dispatch/journey/parser_extras.rb
@@ -2,8 +2,9 @@ require "action_dispatch/journey/scanner"
 require "action_dispatch/journey/nodes/node"
 
 module ActionDispatch
-  module Journey # :nodoc:
-    class Parser < Racc::Parser # :nodoc:
+  # :stopdoc:
+  module Journey
+    class Parser < Racc::Parser
       include Journey::Nodes
 
       def self.parse(string)
@@ -24,4 +25,5 @@ module ActionDispatch
       end
     end
   end
+  # :startdoc:
 end
diff --git a/actionpack/lib/action_dispatch/journey/route.rb b/actionpack/lib/action_dispatch/journey/route.rb
index a9713ff292..f2ac4818d8 100644
--- a/actionpack/lib/action_dispatch/journey/route.rb
+++ b/actionpack/lib/action_dispatch/journey/route.rb
@@ -1,6 +1,7 @@
 module ActionDispatch
-  module Journey # :nodoc:
-    class Route # :nodoc:
+  # :stopdoc:
+  module Journey
+    class Route
       attr_reader :app, :path, :defaults, :name, :precedence
 
       attr_reader :constraints, :internal
@@ -80,9 +81,9 @@ module ActionDispatch
         end
       end
 
-      def requirements # :nodoc:
+      def requirements
         # needed for rails `rails routes`
-        @defaults.merge(path.requirements).delete_if { |_,v|
+        @defaults.merge(path.requirements).delete_if { |_, v|
           /.+?/ == v
         }
       end
@@ -95,13 +96,18 @@ module ActionDispatch
         required_parts + required_defaults.keys
       end
 
-      def score(constraints)
+      def score(supplied_keys)
         required_keys = path.required_names
-        supplied_keys = constraints.map { |k,v| v && k.to_s }.compact
 
-        return -1 unless (required_keys - supplied_keys).empty?
+        required_keys.each do |k|
+          return -1 unless supplied_keys.include?(k)
+        end
+
+        score = 0
+        path.names.each do |k|
+          score += 1 if supplied_keys.include?(k)
+        end
 
-        score = (supplied_keys & path.names).length
         score + (required_defaults.length * 2)
       end
 
@@ -123,7 +129,7 @@ module ActionDispatch
       end
 
       def required_defaults
-        @required_defaults ||= @defaults.dup.delete_if do |k,_|
+        @required_defaults ||= @defaults.dup.delete_if do |k, _|
           parts.include?(k) || !required_default?(k)
         end
       end
@@ -176,4 +182,5 @@ module ActionDispatch
         end
     end
   end
+  # :startdoc:
 end
diff --git a/actionpack/lib/action_dispatch/journey/router.rb b/actionpack/lib/action_dispatch/journey/router.rb
index d0ef549335..084ae9325e 100644
--- a/actionpack/lib/action_dispatch/journey/router.rb
+++ b/actionpack/lib/action_dispatch/journey/router.rb
@@ -109,9 +109,9 @@ module ActionDispatch
           routes.sort_by!(&:precedence)
 
           routes.map! { |r|
-            match_data  = r.path.match(req.path_info)
+            match_data = r.path.match(req.path_info)
             path_parameters = r.defaults.dup
-            match_data.names.zip(match_data.captures) { |name,val|
+            match_data.names.zip(match_data.captures) { |name, val|
               path_parameters[name.to_sym] = Utils.unescape_uri(val) if val
             }
             [match_data, path_parameters, r]
diff --git a/actionpack/lib/action_dispatch/journey/router/utils.rb b/actionpack/lib/action_dispatch/journey/router/utils.rb
index ce5d350763..d641642338 100644
--- a/actionpack/lib/action_dispatch/journey/router/utils.rb
+++ b/actionpack/lib/action_dispatch/journey/router/utils.rb
@@ -58,12 +58,12 @@ module ActionDispatch
             uri.gsub(ESCAPED) { |match| [match[1, 2].hex].pack("C") }.force_encoding(encoding)
           end
 
-          protected
-            def escape(component, pattern)
+          private
+            def escape(component, pattern) # :doc:
               component.gsub(pattern) { |unsafe| percent_encode(unsafe) }.force_encoding(US_ASCII)
             end
 
-            def percent_encode(unsafe)
+            def percent_encode(unsafe) # :doc:
               safe = EMPTY.dup
               unsafe.each_byte { |b| safe << DEC2HEX[b] }
               safe
diff --git a/actionpack/lib/action_dispatch/journey/scanner.rb b/actionpack/lib/action_dispatch/journey/scanner.rb
index 4b8c8ab063..7dbb39b26d 100644
--- a/actionpack/lib/action_dispatch/journey/scanner.rb
+++ b/actionpack/lib/action_dispatch/journey/scanner.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 require "strscan"
 
 module ActionDispatch
@@ -35,22 +36,23 @@ module ActionDispatch
         def scan
           case
             # /
-          when text = @ss.scan(/\//)
-            [:SLASH, text]
+          when @ss.skip(/\//)
+            [:SLASH, "/"]
+          when @ss.skip(/\(/)
+            [:LPAREN, "("]
+          when @ss.skip(/\)/)
+            [:RPAREN, ")"]
+          when @ss.skip(/\|/)
+            [:OR, "|"]
+          when @ss.skip(/\./)
+            [:DOT, "."]
+          when text = @ss.scan(/:\w+/)
+            [:SYMBOL, text]
           when text = @ss.scan(/\*\w+/)
             [:STAR, text]
-          when text = @ss.scan(/(?<!\\)\(/)
-            [:LPAREN, text]
-          when text = @ss.scan(/(?<!\\)\)/)
-            [:RPAREN, text]
-          when text = @ss.scan(/\|/)
-            [:OR, text]
-          when text = @ss.scan(/\./)
-            [:DOT, text]
-          when text = @ss.scan(/(?<!\\):\w+/)
-            [:SYMBOL, text]
-          when text = @ss.scan(/(?:[\w%\-~!$&'*+,;=@]|\\:|\\\(|\\\))+/)
-            [:LITERAL, text.tr('\\', "")]
+          when text = @ss.scan(/(?:[\w%\-~!$&'*+,;=@]|\\[:()])+/)
+            text.tr! "\\", ""
+            [:LITERAL, text]
             # any char
           when text = @ss.scan(/./)
             [:LITERAL, text]
diff --git a/actionpack/lib/action_dispatch/journey/visitors.rb b/actionpack/lib/action_dispatch/journey/visitors.rb
index 452dc84cc5..cda859cba4 100644
--- a/actionpack/lib/action_dispatch/journey/visitors.rb
+++ b/actionpack/lib/action_dispatch/journey/visitors.rb
@@ -1,5 +1,6 @@
 module ActionDispatch
-  module Journey # :nodoc:
+  # :stopdoc:
+  module Journey
     class Format
       ESCAPE_PATH    = ->(value) { Router::Utils.escape_path(value) }
       ESCAPE_SEGMENT = ->(value) { Router::Utils.escape_segment(value) }
@@ -21,7 +22,7 @@ module ActionDispatch
         @children   = []
         @parameters = []
 
-        parts.each_with_index do |object,i|
+        parts.each_with_index do |object, i|
           case object
           when Journey::Format
             @children << i
@@ -261,4 +262,5 @@ module ActionDispatch
       end
     end
   end
+  # :startdoc:
 end
diff --git a/actionpack/lib/action_dispatch/middleware/cookies.rb b/actionpack/lib/action_dispatch/middleware/cookies.rb
index 6f4fab396a..956c53e813 100644
--- a/actionpack/lib/action_dispatch/middleware/cookies.rb
+++ b/actionpack/lib/action_dispatch/middleware/cookies.rb
@@ -179,7 +179,7 @@ module ActionDispatch
 
       # Returns a jar that'll automatically generate a signed representation of cookie value and verify it when reading from
       # the cookie again. This is useful for creating cookies with values that the user is not supposed to change. If a signed
-      # cookie was tampered with by the user (or a 3rd party), nil will be returned.
+      # cookie was tampered with by the user (or a 3rd party), +nil+ will be returned.
       #
       # If +secrets.secret_key_base+ and +secrets.secret_token+ (deprecated) are both set,
       # legacy cookies signed with the old key generator will be transparently upgraded.
@@ -202,7 +202,7 @@ module ActionDispatch
       end
 
       # Returns a jar that'll automatically encrypt cookie values before sending them to the client and will decrypt them for read.
-      # If the cookie was tampered with by the user (or a 3rd party), nil will be returned.
+      # If the cookie was tampered with by the user (or a 3rd party), +nil+ will be returned.
       #
       # If +secrets.secret_key_base+ and +secrets.secret_token+ (deprecated) are both set,
       # legacy cookies signed with the old key generator will be transparently upgraded.
@@ -332,13 +332,13 @@ module ActionDispatch
 
       def update_cookies_from_jar
         request_jar = @request.cookie_jar.instance_variable_get(:@cookies)
-        set_cookies = request_jar.reject { |k,_| @delete_cookies.key?(k) }
+        set_cookies = request_jar.reject { |k, _| @delete_cookies.key?(k) }
 
         @cookies.update set_cookies if set_cookies
       end
 
       def to_header
-        @cookies.map { |k,v| "#{escape(k)}=#{escape(v)}" }.join "; "
+        @cookies.map { |k, v| "#{escape(k)}=#{escape(v)}" }.join "; "
       end
 
       def handle_options(options) #:nodoc:
diff --git a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
index ee644f41c8..1c720c5a8e 100644
--- a/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
+++ b/actionpack/lib/action_dispatch/middleware/debug_exceptions.rb
@@ -38,7 +38,9 @@ module ActionDispatch
       end
 
       def render(*)
-        if logger = ActionView::Base.logger
+        logger = ActionView::Base.logger
+
+        if logger && logger.respond_to?(:silence)
           logger.silence { super }
         else
           super
@@ -173,7 +175,11 @@ module ActionDispatch
       end
 
       def log_array(logger, array)
-        array.map { |line| logger.fatal line }
+        if logger.formatter && logger.formatter.respond_to?(:tags_text)
+          logger.fatal array.join("\n#{logger.formatter.tags_text}")
+        else
+          logger.fatal array.join("\n")
+        end
       end
 
       def logger(request)
diff --git a/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
index 99dc37c568..397f0a8b92 100644
--- a/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
+++ b/actionpack/lib/action_dispatch/middleware/exception_wrapper.rb
@@ -127,7 +127,7 @@ module ActionDispatch
           File.open(full_path, "r") do |file|
             start = [line - 3, 0].max
             lines = file.each_line.drop(start).take(6)
-            Hash[*(start+1..(lines.count+start)).zip(lines).flatten]
+            Hash[*(start + 1..(lines.count + start)).zip(lines).flatten]
           end
         end
       end
diff --git a/actionpack/lib/action_dispatch/middleware/flash.rb b/actionpack/lib/action_dispatch/middleware/flash.rb
index 6900934712..cbe2f4be4d 100644
--- a/actionpack/lib/action_dispatch/middleware/flash.rb
+++ b/actionpack/lib/action_dispatch/middleware/flash.rb
@@ -129,7 +129,7 @@ module ActionDispatch
       end
 
       # Builds a hash containing the flashes to keep for the next request.
-      # If there are none to keep, returns nil.
+      # If there are none to keep, returns +nil+.
       def to_session_value #:nodoc:
         flashes_to_keep = @flashes.except(*@discard)
         return nil if flashes_to_keep.empty?
@@ -281,7 +281,8 @@ module ActionDispatch
           @now
         end
 
-        def stringify_array(array)
+      private
+        def stringify_array(array) # :doc:
           array.map do |item|
             item.kind_of?(Symbol) ? item.to_s : item
           end
diff --git a/actionpack/lib/action_dispatch/middleware/remote_ip.rb b/actionpack/lib/action_dispatch/middleware/remote_ip.rb
index 523eeb5b05..9f1ae80b97 100644
--- a/actionpack/lib/action_dispatch/middleware/remote_ip.rb
+++ b/actionpack/lib/action_dispatch/middleware/remote_ip.rb
@@ -153,9 +153,9 @@ module ActionDispatch
         @ip ||= calculate_ip
       end
 
-    protected
+    private
 
-      def ips_from(header)
+      def ips_from(header) # :doc:
         return [] unless header
         # Split the comma-separated list into an array of strings
         ips = header.strip.split(/[,\s]+/)
@@ -171,7 +171,7 @@ module ActionDispatch
         end
       end
 
-      def filter_proxies(ips)
+      def filter_proxies(ips) # :doc:
         ips.reject do |ip|
           @proxies.any? { |proxy| proxy === ip }
         end
diff --git a/actionpack/lib/action_dispatch/middleware/session/abstract_store.rb b/actionpack/lib/action_dispatch/middleware/session/abstract_store.rb
index 49b82e7128..97c937b0b1 100644
--- a/actionpack/lib/action_dispatch/middleware/session/abstract_store.rb
+++ b/actionpack/lib/action_dispatch/middleware/session/abstract_store.rb
@@ -27,17 +27,16 @@ module ActionDispatch
         sid
       end
 
-    protected
+    private
 
-      def initialize_sid
+      def initialize_sid # :doc:
         @default_options.delete(:sidbits)
         @default_options.delete(:secure_random)
       end
 
-      private
-        def make_request(env)
-          ActionDispatch::Request.new env
-        end
+      def make_request(env)
+        ActionDispatch::Request.new env
+      end
     end
 
     module StaleSessionCheck
diff --git a/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb b/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb
index 8409109ede..57d325a9d8 100644
--- a/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb
+++ b/actionpack/lib/action_dispatch/middleware/session/cookie_store.rb
@@ -63,7 +63,7 @@ module ActionDispatch
     # Other useful options include <tt>:key</tt>, <tt>:secure</tt> and
     # <tt>:httponly</tt>.
     class CookieStore < AbstractStore
-      def initialize(app, options={})
+      def initialize(app, options = {})
         super(app, options.merge!(cookie_only: true))
       end
 
@@ -102,7 +102,7 @@ module ActionDispatch
           end
         end
 
-        def persistent_session_id!(data, sid=nil)
+        def persistent_session_id!(data, sid = nil)
           data ||= {}
           data["session_id"] ||= sid || generate_sid
           data
diff --git a/actionpack/lib/action_dispatch/middleware/ssl.rb b/actionpack/lib/action_dispatch/middleware/ssl.rb
index c9bd417aa2..557721c301 100644
--- a/actionpack/lib/action_dispatch/middleware/ssl.rb
+++ b/actionpack/lib/action_dispatch/middleware/ssl.rb
@@ -23,7 +23,7 @@ module ActionDispatch
   #     `180.days` (recommended).
   #   * `subdomains`: Set to `true` to tell the browser to apply these settings
   #     to all subdomains. This protects your cookies from interception by a
-  #     vulnerable site on a subdomain. Defaults to `false`.
+  #     vulnerable site on a subdomain. Defaults to `true`.
   #   * `preload`: Advertise that this site may be included in browsers'
   #     preloaded HSTS lists. HSTS protects your site on every visit *except the
   #     first visit* since it hasn't seen your HSTS header yet. To close this
diff --git a/actionpack/lib/action_dispatch/request/session.rb b/actionpack/lib/action_dispatch/request/session.rb
index b883ca0f61..a2a80f39fc 100644
--- a/actionpack/lib/action_dispatch/request/session.rb
+++ b/actionpack/lib/action_dispatch/request/session.rb
@@ -53,7 +53,7 @@ module ActionDispatch
           }
         end
 
-        def []=(k,v);         @delegate[k] = v; end
+        def []=(k, v);        @delegate[k] = v; end
         def to_hash;          @delegate.dup; end
         def values_at(*args); @delegate.values_at(*args); end
       end
@@ -85,7 +85,7 @@ module ActionDispatch
       end
 
       # Returns value of the key stored in the session or
-      # nil if the given key is not found in the session.
+      # +nil+ if the given key is not found in the session.
       def [](key)
         load_for_read!
         @delegate[key.to_s]
@@ -124,7 +124,7 @@ module ActionDispatch
       # Returns the session as Hash.
       def to_hash
         load_for_read!
-        @delegate.dup.delete_if { |_,v| v.nil? }
+        @delegate.dup.delete_if { |_, v| v.nil? }
       end
 
       # Updates the session with given Hash.
@@ -162,7 +162,7 @@ module ActionDispatch
       #     :bar
       #   end
       #   # => :bar
-      def fetch(key, default=Unspecified, &block)
+      def fetch(key, default = Unspecified, &block)
         load_for_read!
         if default == Unspecified
           @delegate.fetch(key.to_s, &block)
diff --git a/actionpack/lib/action_dispatch/request/utils.rb b/actionpack/lib/action_dispatch/request/utils.rb
index 282bdbd2be..01bc871e5f 100644
--- a/actionpack/lib/action_dispatch/request/utils.rb
+++ b/actionpack/lib/action_dispatch/request/utils.rb
@@ -4,6 +4,17 @@ module ActionDispatch
       mattr_accessor :perform_deep_munge
       self.perform_deep_munge = true
 
+      def self.each_param_value(params, &block)
+        case params
+        when Array
+          params.each { |element| each_param_value(element, &block) }
+        when Hash
+          params.each_value { |value| each_param_value(value, &block) }
+        when String
+          block.call params
+        end
+      end
+
       def self.normalize_encode_params(params)
         if perform_deep_munge
           NoNilParamEncoder.normalize_encode_params params
diff --git a/actionpack/lib/action_dispatch/routing.rb b/actionpack/lib/action_dispatch/routing.rb
index 61ebd0b8db..c554ce98bc 100644
--- a/actionpack/lib/action_dispatch/routing.rb
+++ b/actionpack/lib/action_dispatch/routing.rb
@@ -1,3 +1,5 @@
+require "active_support/core_ext/string/filters"
+
 module ActionDispatch
   # The routing module provides URL rewriting in native Ruby. It's a way to
   # redirect incoming requests to controllers and actions. This replaces
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index c481c190bf..089aa9f78e 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -1,7 +1,6 @@
 require "active_support/core_ext/hash/slice"
 require "active_support/core_ext/enumerable"
 require "active_support/core_ext/array/extract_options"
-require "active_support/core_ext/regexp"
 require "action_dispatch/routing/redirection"
 require "action_dispatch/routing/endpoint"
 
@@ -568,7 +567,7 @@ module ActionDispatch
         # [:format]
         #   Allows you to specify the default value for optional +format+
         #   segment or disable it by supplying +false+.
-        def match(path, options=nil)
+        def match(path, options = nil)
         end
 
         # Mount a Rack-based application to be used within the application.
@@ -997,65 +996,65 @@ module ActionDispatch
         end
 
         private
-          def merge_path_scope(parent, child) #:nodoc:
+          def merge_path_scope(parent, child)
             Mapper.normalize_path("#{parent}/#{child}")
           end
 
-          def merge_shallow_path_scope(parent, child) #:nodoc:
+          def merge_shallow_path_scope(parent, child)
             Mapper.normalize_path("#{parent}/#{child}")
           end
 
-          def merge_as_scope(parent, child) #:nodoc:
+          def merge_as_scope(parent, child)
             parent ? "#{parent}_#{child}" : child
           end
 
-          def merge_shallow_prefix_scope(parent, child) #:nodoc:
+          def merge_shallow_prefix_scope(parent, child)
             parent ? "#{parent}_#{child}" : child
           end
 
-          def merge_module_scope(parent, child) #:nodoc:
+          def merge_module_scope(parent, child)
             parent ? "#{parent}/#{child}" : child
           end
 
-          def merge_controller_scope(parent, child) #:nodoc:
+          def merge_controller_scope(parent, child)
             child
           end
 
-          def merge_action_scope(parent, child) #:nodoc:
+          def merge_action_scope(parent, child)
             child
           end
 
-          def merge_via_scope(parent, child) #:nodoc:
+          def merge_via_scope(parent, child)
             child
           end
 
-          def merge_format_scope(parent, child) #:nodoc:
+          def merge_format_scope(parent, child)
             child
           end
 
-          def merge_path_names_scope(parent, child) #:nodoc:
+          def merge_path_names_scope(parent, child)
             merge_options_scope(parent, child)
           end
 
-          def merge_constraints_scope(parent, child) #:nodoc:
+          def merge_constraints_scope(parent, child)
             merge_options_scope(parent, child)
           end
 
-          def merge_defaults_scope(parent, child) #:nodoc:
+          def merge_defaults_scope(parent, child)
             merge_options_scope(parent, child)
           end
 
-          def merge_blocks_scope(parent, child) #:nodoc:
+          def merge_blocks_scope(parent, child)
             merged = parent ? parent.dup : []
             merged << child if child
             merged
           end
 
-          def merge_options_scope(parent, child) #:nodoc:
+          def merge_options_scope(parent, child)
             (parent || {}).merge(child)
           end
 
-          def merge_shallow_scope(parent, child) #:nodoc:
+          def merge_shallow_scope(parent, child)
             child ? true : false
           end
 
@@ -1245,11 +1244,11 @@ module ActionDispatch
         # the plural):
         #
         #   GET       /profile/new
-        #   POST      /profile
         #   GET       /profile
         #   GET       /profile/edit
         #   PATCH/PUT /profile
         #   DELETE    /profile
+        #   POST      /profile
         #
         # === Options
         # Takes same options as +resources+.
@@ -1267,15 +1266,15 @@ module ActionDispatch
 
               concerns(options[:concerns]) if options[:concerns]
 
-              collection do
-                post :create
-              end if parent_resource.actions.include?(:create)
-
               new do
                 get :new
               end if parent_resource.actions.include?(:new)
 
               set_member_mappings_for_resource
+
+              collection do
+                post :create
+              end if parent_resource.actions.include?(:create)
             end
           end
 
@@ -1620,13 +1619,13 @@ module ActionDispatch
           end
         end
 
-        protected
+        private
 
-          def parent_resource #:nodoc:
+          def parent_resource
             @scope[:scope_level_resource]
           end
 
-          def apply_common_behavior_for(method, resources, options, &block) #:nodoc:
+          def apply_common_behavior_for(method, resources, options, &block)
             if resources.length > 1
               resources.each { |r| send(method, r, options, &block) }
               return true
@@ -1659,39 +1658,39 @@ module ActionDispatch
             false
           end
 
-          def apply_action_options(options) # :nodoc:
+          def apply_action_options(options)
             return options if action_options? options
             options.merge scope_action_options
           end
 
-          def action_options?(options) #:nodoc:
+          def action_options?(options)
             options[:only] || options[:except]
           end
 
-          def scope_action_options #:nodoc:
+          def scope_action_options
             @scope[:action_options] || {}
           end
 
-          def resource_scope? #:nodoc:
+          def resource_scope?
             @scope.resource_scope?
           end
 
-          def resource_method_scope? #:nodoc:
+          def resource_method_scope?
             @scope.resource_method_scope?
           end
 
-          def nested_scope? #:nodoc:
+          def nested_scope?
             @scope.nested?
           end
 
-          def with_scope_level(kind)
+          def with_scope_level(kind) # :doc:
             @scope = @scope.new_level(kind)
             yield
           ensure
             @scope = @scope.parent
           end
 
-          def resource_scope(resource) #:nodoc:
+          def resource_scope(resource)
             @scope = @scope.new(scope_level_resource: resource)
 
             controller(resource.resource_scope) { yield }
@@ -1699,7 +1698,7 @@ module ActionDispatch
             @scope = @scope.parent
           end
 
-          def nested_options #:nodoc:
+          def nested_options
             options = { as: parent_resource.member_name }
             options[:constraints] = {
               parent_resource.nested_param => param_constraint
@@ -1708,25 +1707,25 @@ module ActionDispatch
             options
           end
 
-          def shallow_nesting_depth #:nodoc:
+          def shallow_nesting_depth
             @scope.find_all { |node|
               node.frame[:scope_level_resource]
             }.count { |node| node.frame[:scope_level_resource].shallow? }
           end
 
-          def param_constraint? #:nodoc:
+          def param_constraint?
             @scope[:constraints] && @scope[:constraints][parent_resource.param].is_a?(Regexp)
           end
 
-          def param_constraint #:nodoc:
+          def param_constraint
             @scope[:constraints][parent_resource.param]
           end
 
-          def canonical_action?(action) #:nodoc:
+          def canonical_action?(action)
             resource_method_scope? && CANONICAL_ACTIONS.include?(action.to_s)
           end
 
-          def shallow_scope #:nodoc:
+          def shallow_scope
             scope = { as: @scope[:shallow_prefix],
                       path: @scope[:shallow_path] }
             @scope = @scope.new scope
@@ -1736,7 +1735,7 @@ module ActionDispatch
             @scope = @scope.parent
           end
 
-          def path_for_action(action, path) #:nodoc:
+          def path_for_action(action, path)
             return "#{@scope[:path]}/#{path}" if path
 
             if canonical_action?(action)
@@ -1746,11 +1745,11 @@ module ActionDispatch
             end
           end
 
-          def action_path(name) #:nodoc:
+          def action_path(name)
             @scope[:path_names][name.to_sym] || name
           end
 
-          def prefix_name_for_action(as, action) #:nodoc:
+          def prefix_name_for_action(as, action)
             if as
               prefix = as
             elsif !canonical_action?(action)
@@ -1762,7 +1761,7 @@ module ActionDispatch
             end
           end
 
-          def name_for_action(as, action) #:nodoc:
+          def name_for_action(as, action)
             prefix = prefix_name_for_action(as, action)
             name_prefix = @scope[:as]
 
@@ -1788,7 +1787,7 @@ module ActionDispatch
             end
           end
 
-          def set_member_mappings_for_resource
+          def set_member_mappings_for_resource # :doc:
             member do
               get :edit if parent_resource.actions.include?(:edit)
               get :show if parent_resource.actions.include?(:show)
@@ -1800,12 +1799,10 @@ module ActionDispatch
             end
           end
 
-          def api_only?
+          def api_only? # :doc:
             @set.api_only?
           end
 
-        private
-
           def path_scope(path)
             @scope = @scope.new(path: merge_path_scope(@scope[:path], path))
             yield
@@ -1869,7 +1866,7 @@ module ActionDispatch
             path =~ %r{^/?[-\w]+/[-\w/]+$}
           end
 
-          def decomposed_match(path, controller, options, _path, to, via, formatted, anchor, options_constraints) # :nodoc:
+          def decomposed_match(path, controller, options, _path, to, via, formatted, anchor, options_constraints)
             if on = options.delete(:on)
               send(on) { decomposed_match(path, controller, options, _path, to, via, formatted, anchor, options_constraints) }
             else
@@ -1884,7 +1881,7 @@ module ActionDispatch
             end
           end
 
-          def add_route(action, controller, options, _path, to, via, formatted, anchor, options_constraints) # :nodoc:
+          def add_route(action, controller, options, _path, to, via, formatted, anchor, options_constraints)
             path = path_for_action(action, _path)
             raise ArgumentError, "path is required" if path.blank?
 
diff --git a/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb b/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
index 4f1aaeefc8..432b9bf4c1 100644
--- a/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
+++ b/actionpack/lib/action_dispatch/routing/polymorphic_routes.rb
@@ -160,7 +160,7 @@ module ActionDispatch
           CACHE = { "path" => {}, "url" => {} }
 
           def self.get(action, type)
-            type   = type.to_s
+            type = type.to_s
             CACHE[type].fetch(action) { build action, type }
           end
 
@@ -266,7 +266,7 @@ module ActionDispatch
 
             args = []
 
-            route  = record_list.map { |parent|
+            route = record_list.map { |parent|
               case parent
               when Symbol, String
                 parent.to_s
@@ -304,7 +304,7 @@ module ActionDispatch
           private
 
             def get_method_for_class(klass)
-              name   = @key_strategy.call klass.model_name
+              name = @key_strategy.call klass.model_name
               get_method_for_string name
             end
 
diff --git a/actionpack/lib/action_dispatch/routing/redirection.rb b/actionpack/lib/action_dispatch/routing/redirection.rb
index 87bcceccc0..4e2318a45e 100644
--- a/actionpack/lib/action_dispatch/routing/redirection.rb
+++ b/actionpack/lib/action_dispatch/routing/redirection.rb
@@ -61,15 +61,15 @@ module ActionDispatch
         end
 
         def escape(params)
-          Hash[params.map { |k,v| [k, Rack::Utils.escape(v)] }]
+          Hash[params.map { |k, v| [k, Rack::Utils.escape(v)] }]
         end
 
         def escape_fragment(params)
-          Hash[params.map { |k,v| [k, Journey::Router::Utils.escape_fragment(v)] }]
+          Hash[params.map { |k, v| [k, Journey::Router::Utils.escape_fragment(v)] }]
         end
 
         def escape_path(params)
-          Hash[params.map { |k,v| [k, Journey::Router::Utils.escape_path(v)] }]
+          Hash[params.map { |k, v| [k, Journey::Router::Utils.escape_path(v)] }]
         end
     end
 
@@ -128,7 +128,7 @@ module ActionDispatch
       end
 
       def inspect
-        "redirect(#{status}, #{options.map { |k,v| "#{k}: #{v}" }.join(', ')})"
+        "redirect(#{status}, #{options.map { |k, v| "#{k}: #{v}" }.join(', ')})"
       end
     end
 
diff --git a/actionpack/lib/action_dispatch/routing/route_set.rb b/actionpack/lib/action_dispatch/routing/route_set.rb
index a1bc357c8b..5853adb110 100644
--- a/actionpack/lib/action_dispatch/routing/route_set.rb
+++ b/actionpack/lib/action_dispatch/routing/route_set.rb
@@ -1,5 +1,4 @@
 require "action_dispatch/journey"
-require "active_support/concern"
 require "active_support/core_ext/object/to_query"
 require "active_support/core_ext/hash/slice"
 require "active_support/core_ext/module/remove_method"
@@ -71,7 +70,7 @@ module ActionDispatch
         private :routes
 
         def initialize
-          @routes  = {}
+          @routes = {}
           @path_helpers = Set.new
           @url_helpers = Set.new
           @url_helpers_module  = Module.new
@@ -208,7 +207,7 @@ module ActionDispatch
                 params = parameterize_args(args) { |missing_key|
                   missing_keys << missing_key
                 }
-                constraints = Hash[@route.requirements.merge(params).sort_by { |k,v| k.to_s }]
+                constraints = Hash[@route.requirements.merge(params).sort_by { |k, v| k.to_s }]
                 message = "No route matches #{constraints.inspect}"
                 message << ", missing required keys: #{missing_keys.sort.inspect}"
 
@@ -647,11 +646,11 @@ module ActionDispatch
 
       # Generate the path indicated by the arguments, and return an array of
       # the keys that were not used to generate it.
-      def extra_keys(options, recall={})
+      def extra_keys(options, recall = {})
         generate_extras(options, recall).last
       end
 
-      def generate_extras(options, recall={})
+      def generate_extras(options, recall = {})
         route_key = options.delete :use_route
         path, params = generate(route_key, options, recall)
         return path, params.keys
@@ -693,7 +692,7 @@ module ActionDispatch
           password = options.delete :password
         end
 
-        recall  = options.delete(:_recall) { {} }
+        recall = options.delete(:_recall) { {} }
 
         original_script_name = options.delete(:original_script_name)
         script_name = find_script_name options
diff --git a/actionpack/lib/action_dispatch/routing/url_for.rb b/actionpack/lib/action_dispatch/routing/url_for.rb
index a1ac5a2b6c..3e564f13d8 100644
--- a/actionpack/lib/action_dispatch/routing/url_for.rb
+++ b/actionpack/lib/action_dispatch/routing/url_for.rb
@@ -198,14 +198,16 @@ module ActionDispatch
           _routes.optimize_routes_generation? && default_url_options.empty?
         end
 
-        def _with_routes(routes)
+      private
+
+        def _with_routes(routes) # :doc:
           old_routes, @_routes = @_routes, routes
           yield
         ensure
           @_routes = old_routes
         end
 
-        def _routes_context
+        def _routes_context # :doc:
           self
         end
     end
diff --git a/actionpack/lib/action_dispatch/testing/assertions/response.rb b/actionpack/lib/action_dispatch/testing/assertions/response.rb
index a2eaccd9ef..817737341c 100644
--- a/actionpack/lib/action_dispatch/testing/assertions/response.rb
+++ b/actionpack/lib/action_dispatch/testing/assertions/response.rb
@@ -50,7 +50,7 @@ module ActionDispatch
       #
       #   # Asserts that the redirection matches the regular expression
       #   assert_redirected_to %r(\Ahttp://example.org)
-      def assert_redirected_to(options = {}, message=nil)
+      def assert_redirected_to(options = {}, message = nil)
         assert_response(:redirect, message)
         return true if options === @response.location
 
diff --git a/actionpack/lib/action_dispatch/testing/assertions/routing.rb b/actionpack/lib/action_dispatch/testing/assertions/routing.rb
index e53bc6af12..454dcb9307 100644
--- a/actionpack/lib/action_dispatch/testing/assertions/routing.rb
+++ b/actionpack/lib/action_dispatch/testing/assertions/routing.rb
@@ -37,7 +37,7 @@ module ActionDispatch
       #
       #   # Test a custom route
       #   assert_recognizes({controller: 'items', action: 'show', id: '1'}, 'view/item1')
-      def assert_recognizes(expected_options, path, extras={}, msg=nil)
+      def assert_recognizes(expected_options, path, extras = {}, msg = nil)
         if path.is_a?(Hash) && path[:method].to_s == "all"
           [:get, :post, :put, :delete].each do |method|
             assert_recognizes(expected_options, path.merge(method: method), extras, msg)
@@ -75,7 +75,7 @@ module ActionDispatch
       #
       #   # Asserts that the generated route gives us our custom route
       #   assert_generates "changesets/12", { controller: 'scm', action: 'show_diff', revision: "12" }
-      def assert_generates(expected_path, options, defaults={}, extras={}, message=nil)
+      def assert_generates(expected_path, options, defaults = {}, extras = {}, message = nil)
         if expected_path =~ %r{://}
           fail_on(URI::InvalidURIError, message) do
             uri = URI.parse(expected_path)
@@ -119,7 +119,7 @@ module ActionDispatch
       #
       #  # Tests a route with an HTTP method
       #  assert_routing({ method: 'put', path: '/product/321' }, { controller: "product", action: "update", id: "321" })
-      def assert_routing(path, options, defaults={}, extras={}, message=nil)
+      def assert_routing(path, options, defaults = {}, extras = {}, message = nil)
         assert_recognizes(options, path, extras, message)
 
         controller, default_controller = options[:controller], defaults[:controller]
diff --git a/actionpack/lib/action_dispatch/testing/integration.rb b/actionpack/lib/action_dispatch/testing/integration.rb
index d137473ef4..021ffec862 100644
--- a/actionpack/lib/action_dispatch/testing/integration.rb
+++ b/actionpack/lib/action_dispatch/testing/integration.rb
@@ -11,62 +11,37 @@ require "action_dispatch/testing/request_encoder"
 module ActionDispatch
   module Integration #:nodoc:
     module RequestHelpers
-      # Performs a GET request with the given parameters.
-      #
-      # - +path+: The URI (as a String) on which you want to perform a GET
-      #   request.
-      # - +params+: The HTTP parameters that you want to pass. This may
-      #   be +nil+,
-      #   a Hash, or a String that is appropriately encoded
-      #   (<tt>application/x-www-form-urlencoded</tt> or
-      #   <tt>multipart/form-data</tt>).
-      # - +headers+: Additional headers to pass, as a Hash. The headers will be
-      #   merged into the Rack env hash.
-      # - +env+: Additional env to pass, as a Hash. The headers will be
-      #   merged into the Rack env hash.
-      #
-      # This method returns a Response object, which one can use to
-      # inspect the details of the response. Furthermore, if this method was
-      # called from an ActionDispatch::IntegrationTest object, then that
-      # object's <tt>@response</tt> instance variable will point to the same
-      # response object.
-      #
-      # You can also perform POST, PATCH, PUT, DELETE, and HEAD requests with
-      # +#post+, +#patch+, +#put+, +#delete+, and +#head+.
-      #
-      # Example:
-      #
-      #   get '/feed', params: { since: 201501011400 }
-      #   post '/profile', headers: { "X-Test-Header" => "testvalue" }
+      # Performs a GET request with the given parameters. See +#process+ for more
+      # details.
       def get(path, **args)
         process(:get, path, **args)
       end
 
-      # Performs a POST request with the given parameters. See +#get+ for more
+      # Performs a POST request with the given parameters. See +#process+ for more
       # details.
       def post(path, **args)
         process(:post, path, **args)
       end
 
-      # Performs a PATCH request with the given parameters. See +#get+ for more
+      # Performs a PATCH request with the given parameters. See +#process+ for more
       # details.
       def patch(path, **args)
         process(:patch, path, **args)
       end
 
-      # Performs a PUT request with the given parameters. See +#get+ for more
+      # Performs a PUT request with the given parameters. See +#process+ for more
       # details.
       def put(path, **args)
         process(:put, path, **args)
       end
 
-      # Performs a DELETE request with the given parameters. See +#get+ for
+      # Performs a DELETE request with the given parameters. See +#process+ for
       # more details.
       def delete(path, **args)
         process(:delete, path, **args)
       end
 
-      # Performs a HEAD request with the given parameters. See +#get+ for more
+      # Performs a HEAD request with the given parameters. See +#process+ for more
       # details.
       def head(path, *args)
         process(:head, path, *args)
@@ -94,7 +69,7 @@ module ActionDispatch
       DEFAULT_HOST = "www.example.com"
 
       include Minitest::Assertions
-      include RequestHelpers, Assertions
+      include TestProcess, RequestHelpers, Assertions
 
       %w( status status_message headers body redirect? ).each do |method|
         delegate method, to: :response, allow_nil: true
@@ -198,101 +173,126 @@ module ActionDispatch
         @https
       end
 
-      # Set the host name to use in the next request.
+      # Performs the actual request.
       #
-      #   session.host! "www.example.com"
-      alias :host! :host=
-
-      private
-        def _mock_session
-          @_mock_session ||= Rack::MockSession.new(@app, host)
+      # - +method+: The HTTP method (GET, POST, PATCH, PUT, DELETE, HEAD, OPTIONS)
+      #   as a symbol.
+      # - +path+: The URI (as a String) on which you want to perform the
+      #   request.
+      # - +params+: The HTTP parameters that you want to pass. This may
+      #   be +nil+,
+      #   a Hash, or a String that is appropriately encoded
+      #   (<tt>application/x-www-form-urlencoded</tt> or
+      #   <tt>multipart/form-data</tt>).
+      # - +headers+: Additional headers to pass, as a Hash. The headers will be
+      #   merged into the Rack env hash.
+      # - +env+: Additional env to pass, as a Hash. The headers will be
+      #   merged into the Rack env hash.
+      #
+      # This method is rarely used directly. Use +#get+, +#post+, or other standard
+      # HTTP methods in integration tests. +#process+ is only required when using a
+      # request method that doesn't have a method defined in the integration tests.
+      #
+      # This method returns a Response object, which one can use to
+      # inspect the details of the response. Furthermore, if this method was
+      # called from an ActionDispatch::IntegrationTest object, then that
+      # object's <tt>@response</tt> instance variable will point to the same
+      # response object.
+      #
+      # Example:
+      #   process :get, '/author', params: { since: 201501011400 }
+      def process(method, path, params: nil, headers: nil, env: nil, xhr: false, as: nil)
+        request_encoder = RequestEncoder.encoder(as)
+        headers ||= {}
+
+        if method == :get && as == :json && params
+          headers["X-Http-Method-Override"] = "GET"
+          method = :post
         end
 
-        # Performs the actual request.
-        def process(method, path, params: nil, headers: nil, env: nil, xhr: false, as: nil)
-          request_encoder = RequestEncoder.encoder(as)
-          headers ||= {}
+        if path =~ %r{://}
+          path = build_expanded_path(path) do |location|
+            https! URI::HTTPS === location if location.scheme
 
-          if method == :get && as == :json && params
-            headers["X-Http-Method-Override"] = "GET"
-            method = :post
+            if url_host = location.host
+              default = Rack::Request::DEFAULT_PORTS[location.scheme]
+              url_host += ":#{location.port}" if default != location.port
+              host! url_host
+            end
           end
+        end
 
-          if path =~ %r{://}
-            path = build_expanded_path(path, request_encoder) do |location|
-              https! URI::HTTPS === location if location.scheme
+        hostname, port = host.split(":")
 
-              if url_host = location.host
-                default = Rack::Request::DEFAULT_PORTS[location.scheme]
-                url_host += ":#{location.port}" if default != location.port
-                host! url_host
-              end
-            end
-          elsif as
-            path = build_expanded_path(path, request_encoder)
-          end
+        request_env = {
+          :method => method,
+          :params => request_encoder.encode_params(params),
 
-          hostname, port = host.split(":")
+          "SERVER_NAME"     => hostname,
+          "SERVER_PORT"     => port || (https? ? "443" : "80"),
+          "HTTPS"           => https? ? "on" : "off",
+          "rack.url_scheme" => https? ? "https" : "http",
 
-          request_env = {
-            :method => method,
-            :params => request_encoder.encode_params(params),
+          "REQUEST_URI"    => path,
+          "HTTP_HOST"      => host,
+          "REMOTE_ADDR"    => remote_addr,
+          "CONTENT_TYPE"   => request_encoder.content_type,
+          "HTTP_ACCEPT"    => request_encoder.accept_header || accept
+        }
 
-            "SERVER_NAME"     => hostname,
-            "SERVER_PORT"     => port || (https? ? "443" : "80"),
-            "HTTPS"           => https? ? "on" : "off",
-            "rack.url_scheme" => https? ? "https" : "http",
+        wrapped_headers = Http::Headers.from_hash({})
+        wrapped_headers.merge!(headers) if headers
 
-            "REQUEST_URI"    => path,
-            "HTTP_HOST"      => host,
-            "REMOTE_ADDR"    => remote_addr,
-            "CONTENT_TYPE"   => request_encoder.content_type,
-            "HTTP_ACCEPT"    => accept
-          }
+        if xhr
+          wrapped_headers["HTTP_X_REQUESTED_WITH"] = "XMLHttpRequest"
+          wrapped_headers["HTTP_ACCEPT"] ||= [Mime[:js], Mime[:html], Mime[:xml], "text/xml", "*/*"].join(", ")
+        end
 
-          wrapped_headers = Http::Headers.from_hash({})
-          wrapped_headers.merge!(headers) if headers
+        # this modifies the passed request_env directly
+        if wrapped_headers.present?
+          Http::Headers.from_hash(request_env).merge!(wrapped_headers)
+        end
+        if env.present?
+          Http::Headers.from_hash(request_env).merge!(env)
+        end
 
-          if xhr
-            wrapped_headers["HTTP_X_REQUESTED_WITH"] = "XMLHttpRequest"
-            wrapped_headers["HTTP_ACCEPT"] ||= [Mime[:js], Mime[:html], Mime[:xml], "text/xml", "*/*"].join(", ")
-          end
+        session = Rack::Test::Session.new(_mock_session)
 
-          # this modifies the passed request_env directly
-          if wrapped_headers.present?
-            Http::Headers.from_hash(request_env).merge!(wrapped_headers)
-          end
-          if env.present?
-            Http::Headers.from_hash(request_env).merge!(env)
-          end
+        # NOTE: rack-test v0.5 doesn't build a default uri correctly
+        # Make sure requested path is always a full uri
+        session.request(build_full_uri(path, request_env), request_env)
 
-          session = Rack::Test::Session.new(_mock_session)
+        @request_count += 1
+        @request = ActionDispatch::Request.new(session.last_request.env)
+        response = _mock_session.last_response
+        @response = ActionDispatch::TestResponse.from_response(response)
+        @response.request = @request
+        @html_document = nil
+        @url_options = nil
 
-          # NOTE: rack-test v0.5 doesn't build a default uri correctly
-          # Make sure requested path is always a full uri
-          session.request(build_full_uri(path, request_env), request_env)
+        @controller = @request.controller_instance
 
-          @request_count += 1
-          @request  = ActionDispatch::Request.new(session.last_request.env)
-          response = _mock_session.last_response
-          @response = ActionDispatch::TestResponse.from_response(response)
-          @response.request = @request
-          @html_document = nil
-          @url_options = nil
+        response.status
+      end
 
-          @controller = @request.controller_instance
+      # Set the host name to use in the next request.
+      #
+      #   session.host! "www.example.com"
+      alias :host! :host=
 
-          response.status
+      private
+        def _mock_session
+          @_mock_session ||= Rack::MockSession.new(@app, host)
         end
 
         def build_full_uri(path, env)
           "#{env['rack.url_scheme']}://#{env['SERVER_NAME']}:#{env['SERVER_PORT']}#{path}"
         end
 
-        def build_expanded_path(path, request_encoder)
+        def build_expanded_path(path)
           location = URI.parse(path)
           yield location if block_given?
-          path = request_encoder.append_format_to location.path
+          path = location.path
           location.query ? "#{path}?#{location.query}" : path
         end
     end
@@ -366,6 +366,7 @@ module ActionDispatch
       # simultaneously.
       def open_session
         dup.tap do |session|
+          session.reset!
           yield session if block_given?
         end
       end
@@ -576,13 +577,15 @@ module ActionDispatch
   #     end
   #   end
   #
-  # The +as+ option sets the format to JSON, sets the content type to
+  # The +as+ option passes an "application/json" Accept header (thereby setting
+  # the request format to JSON unless overridden), sets the content type to
   # "application/json" and encodes the parameters as JSON.
   #
   # Calling +parsed_body+ on the response parses the response body based on the
   # last response MIME type.
   #
-  # For any custom MIME types you've registered, you can even add your own encoders with:
+  # Out of the box, only <tt>:json</tt> is supported. But for any custom MIME
+  # types you've registered, you can add your own encoders with:
   #
   #   ActionDispatch::IntegrationTest.register_encoder :wibble,
   #     param_encoder: -> params { params.to_wibble },
@@ -595,9 +598,7 @@ module ActionDispatch
   # Consult the Rails Testing Guide for more.
 
   class IntegrationTest < ActiveSupport::TestCase
-    include TestProcess
-
-    undef :assigns
+    include TestProcess::FixtureFile
 
     module UrlOptions
       extend ActiveSupport::Concern
diff --git a/actionpack/lib/action_dispatch/testing/request_encoder.rb b/actionpack/lib/action_dispatch/testing/request_encoder.rb
index b0b994b2d0..8c27e9ecb7 100644
--- a/actionpack/lib/action_dispatch/testing/request_encoder.rb
+++ b/actionpack/lib/action_dispatch/testing/request_encoder.rb
@@ -1,10 +1,17 @@
 module ActionDispatch
   class RequestEncoder # :nodoc:
-    @encoders = {}
+    class IdentityEncoder
+      def content_type; end
+      def accept_header; end
+      def encode_params(params); params; end
+      def response_parser; -> body { body }; end
+    end
+
+    @encoders = { identity: IdentityEncoder.new }
 
     attr_reader :response_parser
 
-    def initialize(mime_name, param_encoder, response_parser, url_encoded_form = false)
+    def initialize(mime_name, param_encoder, response_parser)
       @mime = Mime[mime_name]
 
       unless @mime
@@ -12,21 +19,15 @@ module ActionDispatch
           "unregistered MIME Type: #{mime_name}. See `Mime::Type.register`."
       end
 
-      @url_encoded_form = url_encoded_form
-      @path_format      = ".#{@mime.symbol}" unless @url_encoded_form
-      @response_parser  = response_parser || -> body { body }
-      @param_encoder    = param_encoder   || :"to_#{@mime.symbol}".to_proc
+      @response_parser = response_parser || -> body { body }
+      @param_encoder   = param_encoder   || :"to_#{@mime.symbol}".to_proc
     end
 
-    def append_format_to(path)
-      if @url_encoded_form
-        path
-      else
-        path + @path_format
-      end
+    def content_type
+      @mime.to_s
     end
 
-    def content_type
+    def accept_header
       @mime.to_s
     end
 
@@ -40,7 +41,7 @@ module ActionDispatch
     end
 
     def self.encoder(name)
-      @encoders[name] || WWWFormEncoder
+      @encoders[name] || @encoders[:identity]
     end
 
     def self.register_encoder(mime_name, param_encoder: nil, response_parser: nil)
@@ -48,7 +49,5 @@ module ActionDispatch
     end
 
     register_encoder :json, response_parser: -> body { JSON.parse(body) }
-
-    WWWFormEncoder = new(:url_encoded_form, -> params { params }, nil, true)
   end
 end
diff --git a/actionpack/lib/action_dispatch/testing/test_process.rb b/actionpack/lib/action_dispatch/testing/test_process.rb
index 8b03b776fa..0282eb15c3 100644
--- a/actionpack/lib/action_dispatch/testing/test_process.rb
+++ b/actionpack/lib/action_dispatch/testing/test_process.rb
@@ -3,6 +3,26 @@ require "action_dispatch/middleware/flash"
 
 module ActionDispatch
   module TestProcess
+    module FixtureFile
+      # Shortcut for <tt>Rack::Test::UploadedFile.new(File.join(ActionDispatch::IntegrationTest.fixture_path, path), type)</tt>:
+      #
+      #   post :change_avatar, avatar: fixture_file_upload('files/spongebob.png', 'image/png')
+      #
+      # To upload binary files on Windows, pass <tt>:binary</tt> as the last parameter.
+      # This will not affect other platforms:
+      #
+      #   post :change_avatar, avatar: fixture_file_upload('files/spongebob.png', 'image/png', :binary)
+      def fixture_file_upload(path, mime_type = nil, binary = false)
+        if self.class.respond_to?(:fixture_path) && self.class.fixture_path &&
+            !File.exist?(path)
+          path = File.join(self.class.fixture_path, path)
+        end
+        Rack::Test::UploadedFile.new(path, mime_type, binary)
+      end
+    end
+
+    include FixtureFile
+
     def assigns(key = nil)
       raise NoMethodError,
         "assigns has been extracted to a gem. To continue using it,
@@ -24,21 +44,5 @@ module ActionDispatch
     def redirect_to_url
       @response.redirect_url
     end
-
-    # Shortcut for <tt>Rack::Test::UploadedFile.new(File.join(ActionDispatch::IntegrationTest.fixture_path, path), type)</tt>:
-    #
-    #   post :change_avatar, avatar: fixture_file_upload('files/spongebob.png', 'image/png')
-    #
-    # To upload binary files on Windows, pass <tt>:binary</tt> as the last parameter.
-    # This will not affect other platforms:
-    #
-    #   post :change_avatar, avatar: fixture_file_upload('files/spongebob.png', 'image/png', :binary)
-    def fixture_file_upload(path, mime_type = nil, binary = false)
-      if self.class.respond_to?(:fixture_path) && self.class.fixture_path &&
-          !File.exist?(path)
-        path = File.join(self.class.fixture_path, path)
-      end
-      Rack::Test::UploadedFile.new(path, mime_type, binary)
-    end
   end
 end
diff --git a/actionpack/test/abstract/collector_test.rb b/actionpack/test/abstract/collector_test.rb
index 7fe19e6b10..1cd3526483 100644
--- a/actionpack/test/abstract/collector_test.rb
+++ b/actionpack/test/abstract/collector_test.rb
@@ -55,7 +55,7 @@ module AbstractController
         collector.js(:bar) { :baz }
         assert_equal [Mime[:html], [], nil], collector.responses[0]
         assert_equal [Mime[:text], [:foo], nil], collector.responses[1]
-        assert_equal [Mime[:js], [:bar]], collector.responses[2][0,2]
+        assert_equal [Mime[:js], [:bar]], collector.responses[2][0, 2]
         assert_equal :baz, collector.responses[2][2].call
       end
     end
diff --git a/actionpack/test/abstract_unit.rb b/actionpack/test/abstract_unit.rb
index 6d28753947..11a9092527 100644
--- a/actionpack/test/abstract_unit.rb
+++ b/actionpack/test/abstract_unit.rb
@@ -351,7 +351,7 @@ class ResourcesController < ActionController::Base
 end
 
 class CommentsController < ResourcesController; end
-class AccountsController <  ResourcesController; end
+class AccountsController < ResourcesController; end
 class ImagesController < ResourcesController; end
 
 # Skips the current run on Rubinius using Minitest::Assertions#skip
diff --git a/actionpack/test/controller/caching_test.rb b/actionpack/test/controller/caching_test.rb
index 18490c7d73..fa8d9dc09a 100644
--- a/actionpack/test/controller/caching_test.rb
+++ b/actionpack/test/controller/caching_test.rb
@@ -58,7 +58,7 @@ class FragmentCachingTest < ActionController::TestCase
   def test_fragment_cache_key
     assert_equal "views/what a key", @controller.fragment_cache_key("what a key")
     assert_equal "views/test.host/fragment_caching_test/some_action",
-                  @controller.fragment_cache_key(controller: "fragment_caching_test",action: "some_action")
+                  @controller.fragment_cache_key(controller: "fragment_caching_test", action: "some_action")
   end
 
   def test_read_fragment_with_caching_enabled
diff --git a/actionpack/test/controller/filters_test.rb b/actionpack/test/controller/filters_test.rb
index a34878cee8..f9701585a9 100644
--- a/actionpack/test/controller/filters_test.rb
+++ b/actionpack/test/controller/filters_test.rb
@@ -55,7 +55,7 @@ class FilterTest < ActionController::TestCase
       end
     end
 
-    protected
+    private
       (1..3).each do |i|
         define_method "try_#{i}" do
           instance_variable_set :@try, i
@@ -296,7 +296,7 @@ class FilterTest < ActionController::TestCase
       render inline: "ran action"
     end
 
-    protected
+    private
       def find_user
         @ran_filter ||= []
         @ran_filter << "find_user"
@@ -428,7 +428,7 @@ class FilterTest < ActionController::TestCase
       render plain: "bar"
     end
 
-    protected
+    private
       def first
         @first = true
       end
@@ -506,20 +506,20 @@ class FilterTest < ActionController::TestCase
     private
 
       def filter_one
-        @filters  ||= []
-        @filters  << "filter_one"
+        @filters ||= []
+        @filters << "filter_one"
       end
 
       def action_two
-        @filters  << "action_two"
+        @filters << "action_two"
       end
 
       def non_yielding_action
-        @filters  << "it didn't yield"
+        @filters << "it didn't yield"
       end
 
       def action_three
-        @filters  << "action_three"
+        @filters << "action_three"
       end
   end
 
@@ -911,7 +911,7 @@ class ControllerWithFilterInstance < PostsController
 end
 
 class ControllerWithProcFilter < PostsController
-  around_action(only: :no_raise) do |c,b|
+  around_action(only: :no_raise) do |c, b|
     c.instance_variable_set(:"@before", true)
     b.call
     c.instance_variable_set(:"@after", true)
@@ -961,34 +961,34 @@ class YieldingAroundFiltersTest < ActionController::TestCase
 
   def test_base
     controller = PostsController
-    assert_nothing_raised { test_process(controller,"no_raise") }
-    assert_nothing_raised { test_process(controller,"raises_before") }
-    assert_nothing_raised { test_process(controller,"raises_after") }
-    assert_nothing_raised { test_process(controller,"no_action") }
+    assert_nothing_raised { test_process(controller, "no_raise") }
+    assert_nothing_raised { test_process(controller, "raises_before") }
+    assert_nothing_raised { test_process(controller, "raises_after") }
+    assert_nothing_raised { test_process(controller, "no_action") }
   end
 
   def test_with_symbol
     controller = ControllerWithSymbolAsFilter
-    assert_nothing_raised { test_process(controller,"no_raise") }
-    assert_raise(Before) { test_process(controller,"raises_before") }
-    assert_raise(After) { test_process(controller,"raises_after") }
-    assert_nothing_raised { test_process(controller,"no_raise") }
+    assert_nothing_raised { test_process(controller, "no_raise") }
+    assert_raise(Before) { test_process(controller, "raises_before") }
+    assert_raise(After) { test_process(controller, "raises_after") }
+    assert_nothing_raised { test_process(controller, "no_raise") }
   end
 
   def test_with_class
     controller = ControllerWithFilterClass
-    assert_nothing_raised { test_process(controller,"no_raise") }
-    assert_raise(After) { test_process(controller,"raises_after") }
+    assert_nothing_raised { test_process(controller, "no_raise") }
+    assert_raise(After) { test_process(controller, "raises_after") }
   end
 
   def test_with_instance
     controller = ControllerWithFilterInstance
-    assert_nothing_raised { test_process(controller,"no_raise") }
-    assert_raise(After) { test_process(controller,"raises_after") }
+    assert_nothing_raised { test_process(controller, "no_raise") }
+    assert_raise(After) { test_process(controller, "raises_after") }
   end
 
   def test_with_proc
-    test_process(ControllerWithProcFilter,"no_raise")
+    test_process(ControllerWithProcFilter, "no_raise")
     assert @controller.instance_variable_get(:@before)
     assert @controller.instance_variable_get(:@after)
   end
@@ -997,25 +997,25 @@ class YieldingAroundFiltersTest < ActionController::TestCase
     controller = ControllerWithNestedFilters
     assert_nothing_raised do
       begin
-        test_process(controller,"raises_both")
+        test_process(controller, "raises_both")
       rescue Before, After
       end
     end
     assert_raise Before do
       begin
-        test_process(controller,"raises_both")
+        test_process(controller, "raises_both")
       rescue After
       end
     end
   end
 
   def test_action_order_with_all_action_types
-    test_process(ControllerWithAllTypesOfFilters,"no_raise")
+    test_process(ControllerWithAllTypesOfFilters, "no_raise")
     assert_equal "before around (before yield) around_again (before yield) around_again (after yield) after around (after yield)", @controller.instance_variable_get(:@ran_filter).join(" ")
   end
 
   def test_action_order_with_skip_action_method
-    test_process(ControllerWithTwoLessFilters,"no_raise")
+    test_process(ControllerWithTwoLessFilters, "no_raise")
     assert_equal "before around (before yield) around (after yield)", @controller.instance_variable_get(:@ran_filter).join(" ")
   end
 
@@ -1040,7 +1040,7 @@ class YieldingAroundFiltersTest < ActionController::TestCase
     assert_equal 3, controller.instance_variable_get(:@try)
   end
 
-  protected
+  private
     def test_process(controller, action = "show")
       @controller = controller.is_a?(Class) ? controller.new : controller
       process(action)
diff --git a/actionpack/test/controller/flash_hash_test.rb b/actionpack/test/controller/flash_hash_test.rb
index 32f0db71f5..45b598a594 100644
--- a/actionpack/test/controller/flash_hash_test.rb
+++ b/actionpack/test/controller/flash_hash_test.rb
@@ -63,10 +63,10 @@ module ActionDispatch
       assert_equal({ "flashes" => { "foo" => "bar" }, "discard" => [] }, @hash.to_session_value)
 
       @hash.discard("foo")
-      assert_equal(nil, @hash.to_session_value)
+      assert_nil(@hash.to_session_value)
 
       @hash.sweep
-      assert_equal(nil, @hash.to_session_value)
+      assert_nil(@hash.to_session_value)
     end
 
     def test_from_session_value
@@ -75,7 +75,7 @@ module ActionDispatch
       session = Marshal.load(Base64.decode64(rails_3_2_cookie))
       hash = Flash::FlashHash.from_session_value(session["flash"])
       assert_equal({ "greeting" => "Hello" }, hash.to_hash)
-      assert_equal(nil, hash.to_session_value)
+      assert_nil(hash.to_session_value)
     end
 
     def test_from_session_value_on_json_serializer
@@ -84,7 +84,7 @@ module ActionDispatch
       hash = Flash::FlashHash.from_session_value(session["flash"])
 
       assert_equal({ "greeting" => "Hello" }, hash.to_hash)
-      assert_equal(nil, hash.to_session_value)
+      assert_nil(hash.to_session_value)
       assert_equal "Hello", hash[:greeting]
       assert_equal "Hello", hash["greeting"]
     end
@@ -102,8 +102,8 @@ module ActionDispatch
       @hash["foo"] = "bar"
 
       things = []
-      @hash.each do |k,v|
-        things << [k,v]
+      @hash.each do |k, v|
+        things << [k, v]
       end
 
       assert_equal([%w{ hello world }, %w{ foo bar }].sort, things.sort)
diff --git a/actionpack/test/controller/http_digest_authentication_test.rb b/actionpack/test/controller/http_digest_authentication_test.rb
index 343b7b643d..0b59e123d7 100644
--- a/actionpack/test/controller/http_digest_authentication_test.rb
+++ b/actionpack/test/controller/http_digest_authentication_test.rb
@@ -7,7 +7,7 @@ class HttpDigestAuthenticationTest < ActionController::TestCase
     before_action :authenticate_with_request, only: :display
 
     USERS = { "lifo" => "world", "pretty" => "please",
-              "dhh" => ::Digest::MD5::hexdigest(["dhh","SuperSecret","secret"].join(":")) }
+              "dhh" => ::Digest::MD5::hexdigest(["dhh", "SuperSecret", "secret"].join(":")) }
 
     def index
       render plain: "Hello Secret"
@@ -180,7 +180,7 @@ class HttpDigestAuthenticationTest < ActionController::TestCase
 
   test "authentication request with password stored as ha1 digest hash" do
     @request.env["HTTP_AUTHORIZATION"] = encode_credentials(username: "dhh",
-                                           password: ::Digest::MD5::hexdigest(["dhh","SuperSecret","secret"].join(":")),
+                                           password: ::Digest::MD5::hexdigest(["dhh", "SuperSecret", "secret"].join(":")),
                                            password_is_ha1: true)
     get :display
 
diff --git a/actionpack/test/controller/http_token_authentication_test.rb b/actionpack/test/controller/http_token_authentication_test.rb
index 3842136682..09d2793c9a 100644
--- a/actionpack/test/controller/http_token_authentication_test.rb
+++ b/actionpack/test/controller/http_token_authentication_test.rb
@@ -166,8 +166,7 @@ class HttpTokenAuthenticationTest < ActionController::TestCase
 
   test "token_and_options returns nil with no value after the equal sign" do
     actual = ActionController::HttpAuthentication::Token.token_and_options(malformed_request).first
-    expected = nil
-    assert_equal(expected, actual)
+    assert_nil actual
   end
 
   test "raw_params returns a tuple of two key value pair strings" do
diff --git a/actionpack/test/controller/integration_test.rb b/actionpack/test/controller/integration_test.rb
index 652c0f0dd2..4fae4071b1 100644
--- a/actionpack/test/controller/integration_test.rb
+++ b/actionpack/test/controller/integration_test.rb
@@ -145,7 +145,7 @@ class IntegrationTestTest < ActiveSupport::TestCase
         name.to_s == "foo" ? "pass" : super
       end
     end
-    @test.class.superclass.__send__(:include, mixin)
+    @test.class.superclass.include(mixin)
     begin
       assert_equal "pass", @test.foo
     ensure
@@ -153,14 +153,6 @@ class IntegrationTestTest < ActiveSupport::TestCase
       mixin.__send__(:remove_method, :method_missing)
     end
   end
-
-  def test_assigns_is_undefined_and_not_point_to_the_gem
-    e = assert_raises(NoMethodError) do
-      @test.assigns(:foo)
-    end
-
-    assert_match(/undefined method/, e.message)
-  end
 end
 
 # Tests that integration tests don't call Controller test methods for processing.
@@ -281,7 +273,7 @@ class IntegrationProcessTest < ActionDispatch::IntegrationTest
       self.cookies["cookie_2"] = "oatmeal"
       get "/cookie_monster"
       assert_equal "cookie_1=; path=/\ncookie_3=chocolate; path=/", headers["Set-Cookie"]
-      assert_equal({ "cookie_1"=>"", "cookie_2"=>"oatmeal", "cookie_3"=>"chocolate" }, cookies.to_hash)
+      assert_equal({ "cookie_1" => "", "cookie_2" => "oatmeal", "cookie_3" => "chocolate" }, cookies.to_hash)
     end
   end
 
@@ -291,14 +283,14 @@ class IntegrationProcessTest < ActionDispatch::IntegrationTest
       assert_response :success
 
       assert_equal "foo=bar; path=/", headers["Set-Cookie"]
-      assert_equal({ "foo"=>"bar" }, cookies.to_hash)
+      assert_equal({ "foo" => "bar" }, cookies.to_hash)
 
       get "/get_cookie"
       assert_response :success
       assert_equal "bar", body
 
-      assert_equal nil, headers["Set-Cookie"]
-      assert_equal({ "foo"=>"bar" }, cookies.to_hash)
+      assert_nil headers["Set-Cookie"]
+      assert_equal({ "foo" => "bar" }, cookies.to_hash)
     end
   end
 
@@ -310,14 +302,14 @@ class IntegrationProcessTest < ActionDispatch::IntegrationTest
       assert_response :success
 
       assert_equal "foo=bar; path=/", headers["Set-Cookie"]
-      assert_equal({ "foo"=>"bar" }, cookies.to_hash)
+      assert_equal({ "foo" => "bar" }, cookies.to_hash)
 
       get "/get_cookie"
       assert_response :success
       assert_equal "bar", body
 
-      assert_equal nil, headers["Set-Cookie"]
-      assert_equal({ "foo"=>"bar" }, cookies.to_hash)
+      assert_nil headers["Set-Cookie"]
+      assert_equal({ "foo" => "bar" }, cookies.to_hash)
     end
   end
 
@@ -364,6 +356,14 @@ class IntegrationProcessTest < ActionDispatch::IntegrationTest
     end
   end
 
+  test "creation of multiple integration sessions" do
+    integration_session # initialize first session
+    a = open_session
+    b = open_session
+
+    refute_same(a.integration_session, b.integration_session)
+  end
+
   def test_get_with_query_string
     with_test_route_set do
       get "/get_with_params?foo=bar"
@@ -924,12 +924,16 @@ class IntegrationRequestsWithSessionSetup < ActionDispatch::IntegrationTest
 
   def test_cookies_set_in_setup_are_persisted_through_the_session
     get "/foo"
-    assert_equal({ "user_name"=>"david" }, cookies.to_hash)
+    assert_equal({ "user_name" => "david" }, cookies.to_hash)
   end
 end
 
 class IntegrationRequestEncodersTest < ActionDispatch::IntegrationTest
   class FooController < ActionController::Base
+    def foos
+      render plain: "ok"
+    end
+
     def foos_json
       render json: params.permit(:foo)
     end
@@ -958,13 +962,30 @@ class IntegrationRequestEncodersTest < ActionDispatch::IntegrationTest
   def test_encoding_as_json
     post_to_foos as: :json do
       assert_response :success
-      assert_match "foos_json.json", request.path
       assert_equal "application/json", request.content_type
+      assert_equal "application/json", request.accepts.first.to_s
+      assert_equal :json, request.format.ref
       assert_equal({ "foo" => "fighters" }, request.request_parameters)
       assert_equal({ "foo" => "fighters" }, response.parsed_body)
     end
   end
 
+  def test_doesnt_mangle_request_path
+    with_routing do |routes|
+      routes.draw do
+        ActiveSupport::Deprecation.silence do
+          post ":action" => FooController
+        end
+      end
+
+      post "/foos"
+      assert_equal "/foos", request.path
+
+      post "/foos_json", as: :json
+      assert_equal "/foos_json", request.path
+    end
+  end
+
   def test_encoding_as_without_mime_registration
     assert_raise ArgumentError do
       ActionDispatch::IntegrationTest.register_encoder :wibble
@@ -979,8 +1000,10 @@ class IntegrationRequestEncodersTest < ActionDispatch::IntegrationTest
 
     post_to_foos as: :wibble do
       assert_response :success
-      assert_match "foos_wibble.wibble", request.path
+      assert_equal "/foos_wibble", request.path
       assert_equal "text/wibble", request.content_type
+      assert_equal "text/wibble", request.accepts.first.to_s
+      assert_equal :wibble, request.format.ref
       assert_equal Hash.new, request.request_parameters # Unregistered MIME Type can't be parsed.
       assert_equal "ok", response.parsed_body
     end
@@ -1078,8 +1101,8 @@ class IntegrationFileUploadTest < ActionDispatch::IntegrationTest
   def test_fixture_file_upload
     post "/test_file_upload",
       params: {
-        file: fixture_file_upload("/mona_lisa.jpg", "image/jpg")
+        file: fixture_file_upload("/ruby_on_rails.jpg", "image/jpg")
       }
-    assert_equal "159528", @response.body
+    assert_equal "45142", @response.body
   end
 end
diff --git a/actionpack/test/controller/mime/accept_format_test.rb b/actionpack/test/controller/mime/accept_format_test.rb
index a2834c9f39..a22fa39051 100644
--- a/actionpack/test/controller/mime/accept_format_test.rb
+++ b/actionpack/test/controller/mime/accept_format_test.rb
@@ -40,7 +40,7 @@ class PostController < AbstractPostController
     respond_to(:html, :iphone, :js)
   end
 
-protected
+private
 
   def with_iphone
     request.format = "iphone" if request.env["HTTP_ACCEPT"] == "text/iphone"
diff --git a/actionpack/test/controller/mime/respond_to_test.rb b/actionpack/test/controller/mime/respond_to_test.rb
index c5f8165d04..818dc119eb 100644
--- a/actionpack/test/controller/mime/respond_to_test.rb
+++ b/actionpack/test/controller/mime/respond_to_test.rb
@@ -273,7 +273,7 @@ class RespondToController < ActionController::Base
     end
   end
 
-  protected
+  private
     def set_layout
       case action_name
       when "all_types_with_layout", "iphone_with_html_response_type"
diff --git a/actionpack/test/controller/new_base/bare_metal_test.rb b/actionpack/test/controller/new_base/bare_metal_test.rb
index 9956f0b107..054757fab3 100644
--- a/actionpack/test/controller/new_base/bare_metal_test.rb
+++ b/actionpack/test/controller/new_base/bare_metal_test.rb
@@ -52,7 +52,7 @@ module BareMetalTest
       controller.set_request!(ActionDispatch::Request.empty)
       controller.set_response!(BareController.make_response!(controller.request))
       controller.index
-      assert_equal nil, controller.response_body
+      assert_nil controller.response_body
     end
   end
 
diff --git a/actionpack/test/controller/new_base/base_test.rb b/actionpack/test/controller/new_base/base_test.rb
index 3765d406fc..b891df4c0f 100644
--- a/actionpack/test/controller/new_base/base_test.rb
+++ b/actionpack/test/controller/new_base/base_test.rb
@@ -25,7 +25,7 @@ module Dispatching
       render body: "actions: #{action_methods.to_a.sort.join(', ')}"
     end
 
-    protected
+    private
       def authenticate
       end
   end
diff --git a/actionpack/test/controller/new_base/render_context_test.rb b/actionpack/test/controller/new_base/render_context_test.rb
index b64468a94e..25b73ac78c 100644
--- a/actionpack/test/controller/new_base/render_context_test.rb
+++ b/actionpack/test/controller/new_base/render_context_test.rb
@@ -26,16 +26,14 @@ module RenderContext
       render action: "hello_world", layout: "basic"
     end
 
-    protected
-
-      # 3) Set view_context to self
-      def view_context
-        self
-      end
+    protected def __controller_method__
+      "controller context!"
+    end
 
-      def __controller_method__
-        "controller context!"
-      end
+    # 3) Set view_context to self
+    private def view_context
+      self
+    end
   end
 
   class RenderContextTest < Rack::TestCase
diff --git a/actionpack/test/controller/new_base/render_streaming_test.rb b/actionpack/test/controller/new_base/render_streaming_test.rb
index 5cd8f82323..1177b8b03e 100644
--- a/actionpack/test/controller/new_base/render_streaming_test.rb
+++ b/actionpack/test/controller/new_base/render_streaming_test.rb
@@ -101,12 +101,12 @@ module RenderStreaming
       assert_body "Hello world, I'm here!"
       assert_status 200
       assert_equal "22", headers["Content-Length"]
-      assert_equal nil, headers["Transfer-Encoding"]
+      assert_nil headers["Transfer-Encoding"]
     end
 
-    def assert_streaming!(cache="no-cache")
+    def assert_streaming!(cache = "no-cache")
       assert_status 200
-      assert_equal nil, headers["Content-Length"]
+      assert_nil headers["Content-Length"]
       assert_equal "chunked", headers["Transfer-Encoding"]
       assert_equal cache, headers["Cache-Control"]
     end
diff --git a/actionpack/test/controller/parameter_encoding_test.rb b/actionpack/test/controller/parameter_encoding_test.rb
index 7840b4f5c4..234d0bddd1 100644
--- a/actionpack/test/controller/parameter_encoding_test.rb
+++ b/actionpack/test/controller/parameter_encoding_test.rb
@@ -1,9 +1,8 @@
 require "abstract_unit"
 
 class ParameterEncodingController < ActionController::Base
-  parameter_encoding :test_bar,          :bar, Encoding::ASCII_8BIT
-  parameter_encoding :test_baz,          :baz, Encoding::ISO_8859_1
-  parameter_encoding :test_baz_to_ascii, :baz, Encoding::ASCII_8BIT
+  skip_parameter_encoding :test_bar
+  skip_parameter_encoding :test_all_values_encoding
 
   def test_foo
     render body: params[:foo].encoding
@@ -13,16 +12,8 @@ class ParameterEncodingController < ActionController::Base
     render body: params[:bar].encoding
   end
 
-  def test_baz
-    render body: params[:baz].encoding
-  end
-
-  def test_no_change_to_baz
-    render body: params[:baz].encoding
-  end
-
-  def test_baz_to_ascii
-    render body: params[:baz].encoding
+  def test_all_values_encoding
+    render body: ::JSON.dump(params.values.map(&:encoding).map(&:name))
   end
 end
 
@@ -36,32 +27,18 @@ class ParameterEncodingTest < ActionController::TestCase
     assert_equal "UTF-8", @response.body
   end
 
-  test "properly transcodes ASCII_8BIT parameters into declared encodings" do
+  test "properly encodes ASCII_8BIT parameters into binary" do
     post :test_bar, params: { "foo" => "foo", "bar" => "bar", "baz" => "baz" }
 
     assert_response :success
     assert_equal "ASCII-8BIT", @response.body
   end
 
-  test "properly transcodes ISO_8859_1 parameters into declared encodings" do
-    post :test_baz, params: { "foo" => "foo", "bar" => "bar", "baz" => "baz" }
-
-    assert_response :success
-    assert_equal "ISO-8859-1", @response.body
-  end
-
-  test "does not transcode parameters when not specified" do
-    post :test_no_change_to_baz, params: { "foo" => "foo", "bar" => "bar", "baz" => "baz" }
+  test "properly encodes all ASCII_8BIT parameters into binary" do
+    post :test_all_values_encoding, params: { "foo" => "foo", "bar" => "bar", "baz" => "baz" }
 
     assert_response :success
-    assert_equal "UTF-8", @response.body
-  end
-
-  test "respects different encoding declarations for a param per action" do
-    post :test_baz_to_ascii, params: { "foo" => "foo", "bar" => "bar", "baz" => "baz" }
-
-    assert_response :success
-    assert_equal "ASCII-8BIT", @response.body
+    assert_equal ["ASCII-8BIT"], JSON.parse(@response.body).uniq
   end
 
   test "does not raise an error when passed a param declared as ASCII-8BIT that contains invalid bytes" do
diff --git a/actionpack/test/controller/parameters/mutators_test.rb b/actionpack/test/controller/parameters/mutators_test.rb
index e060e5180f..e61bbdbe13 100644
--- a/actionpack/test/controller/parameters/mutators_test.rb
+++ b/actionpack/test/controller/parameters/mutators_test.rb
@@ -45,11 +45,11 @@ class ParametersMutatorsTest < ActiveSupport::TestCase
 
   test "keep_if retains permitted status" do
     @params.permit!
-    assert @params.keep_if { |k,v| k == "person" }.permitted?
+    assert @params.keep_if { |k, v| k == "person" }.permitted?
   end
 
   test "keep_if retains unpermitted status" do
-    assert_not @params.keep_if { |k,v| k == "person" }.permitted?
+    assert_not @params.keep_if { |k, v| k == "person" }.permitted?
   end
 
   test "reject! retains permitted status" do
diff --git a/actionpack/test/controller/parameters/parameters_permit_test.rb b/actionpack/test/controller/parameters/parameters_permit_test.rb
index 728d8e1279..b62a3d6d7b 100644
--- a/actionpack/test/controller/parameters/parameters_permit_test.rb
+++ b/actionpack/test/controller/parameters/parameters_permit_test.rb
@@ -28,7 +28,7 @@ class ParametersPermitTest < ActiveSupport::TestCase
   end
 
   def walk_permitted(params)
-    params.each do |k,v|
+    params.each do |k, v|
       case v
       when ActionController::Parameters
         walk_permitted v
@@ -39,13 +39,13 @@ class ParametersPermitTest < ActiveSupport::TestCase
   end
 
   test "iteration should not impact permit" do
-    hash = { "foo"=>{ "bar"=>{ "0"=>{ "baz"=>"hello", "zot"=>"1" } } } }
+    hash = { "foo" => { "bar" => { "0" => { "baz" => "hello", "zot" => "1" } } } }
     params = ActionController::Parameters.new(hash)
 
     walk_permitted params
 
     sanitized = params[:foo].permit(bar: [:baz])
-    assert_equal({ "0"=>{ "baz"=>"hello" } }, sanitized[:bar].to_unsafe_h)
+    assert_equal({ "0" => { "baz" => "hello" } }, sanitized[:bar].to_unsafe_h)
   end
 
   test "if nothing is permitted, the hash becomes empty" do
@@ -141,7 +141,7 @@ class ParametersPermitTest < ActiveSupport::TestCase
     permitted = params.permit(:a, c: [], b: [])
     assert_equal 1, permitted[:a]
     assert_equal [1, 2, 3], permitted[:b]
-    assert_equal nil, permitted[:c]
+    assert_nil permitted[:c]
   end
 
   test "key to empty array: arrays of permitted scalars pass" do
@@ -168,6 +168,44 @@ class ParametersPermitTest < ActiveSupport::TestCase
     end
   end
 
+  test "key to empty hash: arbitrary hashes are permitted" do
+    params = ActionController::Parameters.new(
+      username: "fxn",
+      preferences: {
+        scheme: "Marazul",
+        font: {
+          name: "Source Code Pro",
+          size: 12
+        },
+        tabstops:   [4, 8, 12, 16],
+        suspicious: [true, Object.new, false, /yo!/],
+        dubious:    [{ a: :a, b: /wtf!/ }, { c: :c }],
+        injected:   Object.new
+      },
+      hacked: 1 # not a hash
+    )
+
+    permitted = params.permit(:username, preferences: {}, hacked: {})
+
+    assert permitted.permitted?
+    assert permitted[:preferences].permitted?
+    assert permitted[:preferences][:font].permitted?
+    assert permitted[:preferences][:dubious].all?(&:permitted?)
+
+    assert_equal "fxn",             permitted[:username]
+    assert_equal "Marazul",         permitted[:preferences][:scheme]
+    assert_equal "Source Code Pro", permitted[:preferences][:font][:name]
+    assert_equal 12,                permitted[:preferences][:font][:size]
+    assert_equal [4, 8, 12, 16],    permitted[:preferences][:tabstops]
+    assert_equal [true, false],     permitted[:preferences][:suspicious]
+    assert_equal :a,                permitted[:preferences][:dubious][0][:a]
+    assert_equal :c,                permitted[:preferences][:dubious][1][:c]
+
+    assert_filtered_out permitted[:preferences][:dubious][0], :b
+    assert_filtered_out permitted[:preferences], :injected
+    assert_filtered_out permitted, :hacked
+  end
+
   test "fetch raises ParameterMissing exception" do
     e = assert_raises(ActionController::ParameterMissing) do
       @params.fetch :foo
@@ -178,7 +216,7 @@ class ParametersPermitTest < ActiveSupport::TestCase
   test "fetch with a default value of a hash does not mutate the object" do
     params = ActionController::Parameters.new({})
     params.fetch :foo, {}
-    assert_equal nil, params[:foo]
+    assert_nil params[:foo]
   end
 
   test "hashes in array values get wrapped" do
@@ -216,8 +254,8 @@ class ParametersPermitTest < ActiveSupport::TestCase
   end
 
   test "fetch doesnt raise ParameterMissing exception if there is a default that is nil" do
-    assert_equal nil, @params.fetch(:foo, nil)
-    assert_equal nil, @params.fetch(:foo) { nil }
+    assert_nil @params.fetch(:foo, nil)
+    assert_nil @params.fetch(:foo) { nil }
   end
 
   test "KeyError in fetch block should not be covered up" do
@@ -244,6 +282,23 @@ class ParametersPermitTest < ActiveSupport::TestCase
     assert merged_params[:id]
   end
 
+  test "not permitted is sticky beyond merge!" do
+    assert_not @params.merge!(a: "b").permitted?
+  end
+
+  test "permitted is sticky beyond merge!" do
+    @params.permit!
+    assert @params.merge!(a: "b").permitted?
+  end
+
+  test "merge! with parameters" do
+    other_params = ActionController::Parameters.new(id: "1234").permit!
+    @params.merge!(other_params)
+
+    assert_equal "1234", @params[:id]
+    assert_equal "32", @params[:person][:age]
+  end
+
   test "modifying the parameters" do
     @params[:person][:hometown] = "Chicago"
     @params[:person][:family] = { brother: "Jonas" }
@@ -322,8 +377,8 @@ class ParametersPermitTest < ActiveSupport::TestCase
   end
 
   test "to_unsafe_h returns unfiltered params even after accessing few keys" do
-    params = ActionController::Parameters.new("f"=>{ "language_facet"=>["Tibetan"] })
-    expected = { "f"=>{ "language_facet"=>["Tibetan"] } }
+    params = ActionController::Parameters.new("f" => { "language_facet" => ["Tibetan"] })
+    expected = { "f" => { "language_facet" => ["Tibetan"] } }
 
     assert params["f"].is_a? ActionController::Parameters
     assert_equal expected, params.to_unsafe_h
diff --git a/actionpack/test/controller/parameters/serialization_test.rb b/actionpack/test/controller/parameters/serialization_test.rb
index 4fb1564c68..6fba2fde91 100644
--- a/actionpack/test/controller/parameters/serialization_test.rb
+++ b/actionpack/test/controller/parameters/serialization_test.rb
@@ -14,12 +14,10 @@ class ParametersSerializationTest < ActiveSupport::TestCase
 
   test "yaml serialization" do
     params = ActionController::Parameters.new(key: :value)
-    assert_equal <<-end_of_yaml.strip_heredoc, YAML.dump(params)
-      --- !ruby/object:ActionController::Parameters
-      parameters: !ruby/hash:ActiveSupport::HashWithIndifferentAccess
-        key: :value
-      permitted: false
-    end_of_yaml
+    yaml_dump = YAML.dump(params)
+    assert_match("--- !ruby/object:ActionController::Parameters", yaml_dump)
+    assert_match(/parameters: !ruby\/hash:ActiveSupport::HashWithIndifferentAccess\n\s+key: :value/, yaml_dump)
+    assert_match("permitted: false", yaml_dump)
   end
 
   test "yaml deserialization" do
diff --git a/actionpack/test/controller/params_wrapper_test.rb b/actionpack/test/controller/params_wrapper_test.rb
index 1549405fe7..faa57c4559 100644
--- a/actionpack/test/controller/params_wrapper_test.rb
+++ b/actionpack/test/controller/params_wrapper_test.rb
@@ -50,7 +50,7 @@ class ParamsWrapperTest < ActionController::TestCase
     with_default_wrapper_options do
       @request.env["CONTENT_TYPE"] = "application/json"
       post :parse, params: { "username" => "sikachu" }
-      assert_equal @request.filtered_parameters, "controller" => "params_wrapper_test/users", "action" => "parse", "username" => "sikachu", "user" => { "username" => "sikachu" }
+      assert_equal({ "controller" => "params_wrapper_test/users", "action" => "parse", "username" => "sikachu", "user" => { "username" => "sikachu" } }, @request.filtered_parameters)
     end
   end
 
@@ -212,6 +212,16 @@ class ParamsWrapperTest < ActionController::TestCase
       )
     end
   end
+
+  def test_handles_empty_content_type
+    with_default_wrapper_options do
+      @request.env["CONTENT_TYPE"] = nil
+      _controller_class.dispatch(:parse, @request, @response)
+
+      assert_equal 200, @response.status
+      assert_equal "", @response.body
+    end
+  end
 end
 
 class NamespacedParamsWrapperTest < ActionController::TestCase
diff --git a/actionpack/test/controller/redirect_test.rb b/actionpack/test/controller/redirect_test.rb
index 0e61b92bcf..e4e968dfdb 100644
--- a/actionpack/test/controller/redirect_test.rb
+++ b/actionpack/test/controller/redirect_test.rb
@@ -123,7 +123,7 @@ class RedirectController < ActionController::Base
 
   def rescue_errors(e) raise e end
 
-  protected
+  private
     def dashbord_url(id, message)
       url_for action: "dashboard", params: { "id" => id, "message" => message }
     end
diff --git a/actionpack/test/controller/render_json_test.rb b/actionpack/test/controller/render_json_test.rb
index 213829bd9e..79552ec8f1 100644
--- a/actionpack/test/controller/render_json_test.rb
+++ b/actionpack/test/controller/render_json_test.rb
@@ -5,7 +5,7 @@ require "pathname"
 
 class RenderJsonTest < ActionController::TestCase
   class JsonRenderable
-    def as_json(options={})
+    def as_json(options = {})
       hash = { a: :b, c: :d, e: :f }
       hash.except!(*options[:except]) if options[:except]
       hash
diff --git a/actionpack/test/controller/render_test.rb b/actionpack/test/controller/render_test.rb
index 76139d59e2..0c0f18f200 100644
--- a/actionpack/test/controller/render_test.rb
+++ b/actionpack/test/controller/render_test.rb
@@ -368,7 +368,7 @@ class ExpiresInRenderTest < ActionController::TestCase
   end
 
   def test_date_header_when_expires_in
-    time = Time.mktime(2011,10,30)
+    time = Time.mktime(2011, 10, 30)
     Time.stub :now, time do
       get :conditional_hello_with_expires_in
       assert_equal Time.now.httpdate, @response.headers["Date"]
diff --git a/actionpack/test/controller/renderer_test.rb b/actionpack/test/controller/renderer_test.rb
index d6f09f2d90..866600b935 100644
--- a/actionpack/test/controller/renderer_test.rb
+++ b/actionpack/test/controller/renderer_test.rb
@@ -60,6 +60,14 @@ class RendererTest < ActiveSupport::TestCase
     assert_equal "true", content
   end
 
+  test "rendering with custom env using a key that is not in RACK_KEY_TRANSLATION" do
+    value    = "warden is here"
+    renderer = ApplicationController.renderer.new warden: value
+    content  = renderer.render inline: "<%= request.env['warden'] %>"
+
+    assert_equal value, content
+  end
+
   test "rendering with defaults" do
     renderer = ApplicationController.renderer.new https: true
     content = renderer.render inline: "<%= request.ssl? %>"
diff --git a/actionpack/test/controller/renderers_test.rb b/actionpack/test/controller/renderers_test.rb
index 122f5be549..ccc700d79c 100644
--- a/actionpack/test/controller/renderers_test.rb
+++ b/actionpack/test/controller/renderers_test.rb
@@ -10,7 +10,7 @@ class RenderersTest < ActionController::TestCase
     end
   end
   class JsonRenderable
-    def as_json(options={})
+    def as_json(options = {})
       hash = { a: :b, c: :d, e: :f }
       hash.except!(*options[:except]) if options[:except]
       hash
diff --git a/actionpack/test/controller/request/test_request_test.rb b/actionpack/test/controller/request/test_request_test.rb
index fa049fbc9f..b67ae72c0a 100644
--- a/actionpack/test/controller/request/test_request_test.rb
+++ b/actionpack/test/controller/request/test_request_test.rb
@@ -8,7 +8,17 @@ class ActionController::TestRequestTest < ActionController::TestCase
 
   def test_mutating_session_options_does_not_affect_default_options
     @request.session_options[:myparam] = 123
-    assert_equal nil, ActionController::TestSession::DEFAULT_OPTIONS[:myparam]
+    assert_nil ActionController::TestSession::DEFAULT_OPTIONS[:myparam]
+  end
+
+  def test_content_length_has_bytes_count_value
+    non_ascii_parameters = { data: { content: "Latin + Кириллица" } }
+    @request.set_header "REQUEST_METHOD", "POST"
+    @request.set_header "CONTENT_TYPE", "application/json"
+    @request.assign_parameters(@routes, "test", "create", non_ascii_parameters,
+                               "/test", [:data, :controller, :action])
+    assert_equal(StringIO.new(non_ascii_parameters.to_json).length.to_s,
+                 @request.get_header("CONTENT_LENGTH"))
   end
 
   ActionDispatch::Session::AbstractStore::DEFAULT_OPTIONS.each_key do |option|
diff --git a/actionpack/test/controller/request_forgery_protection_test.rb b/actionpack/test/controller/request_forgery_protection_test.rb
index 90d5ab3c67..d645ddfdbe 100644
--- a/actionpack/test/controller/request_forgery_protection_test.rb
+++ b/actionpack/test/controller/request_forgery_protection_test.rb
@@ -92,7 +92,7 @@ class PrependProtectForgeryBaseController < ActionController::Base
     render inline: "OK"
   end
 
-  protected
+  private
 
     def add_called_callback(name)
       @called_callbacks ||= []
diff --git a/actionpack/test/controller/rescue_test.rb b/actionpack/test/controller/rescue_test.rb
index a98e6479b7..9ae22c4554 100644
--- a/actionpack/test/controller/rescue_test.rb
+++ b/actionpack/test/controller/rescue_test.rb
@@ -149,7 +149,7 @@ class RescueController < ActionController::Base
     raise RangeError
   end
 
-  protected
+  private
     def deny_access
       head :forbidden
     end
@@ -327,7 +327,7 @@ class RescueTest < ActionDispatch::IntegrationTest
       raise "b00m"
     end
 
-    protected
+    private
       def show_errors(exception)
         render plain: exception.message
       end
diff --git a/actionpack/test/controller/resources_test.rb b/actionpack/test/controller/resources_test.rb
index b572e7e8d5..fad34dacce 100644
--- a/actionpack/test/controller/resources_test.rb
+++ b/actionpack/test/controller/resources_test.rb
@@ -27,7 +27,7 @@ class ResourcesTest < ActionController::TestCase
 
   def test_override_paths_for_member_and_collection_methods
     collection_methods = { rss: :get, reorder: :post, csv: :post }
-    member_methods    = { rss: :get, atom: :get, upload: :post, fix: :post }
+    member_methods = { rss: :get, atom: :get, upload: :post, fix: :post }
     path_names = { new: "nuevo", rss: "canal", fix: "corrigir" }
 
     with_restful_routing :messages,
@@ -792,7 +792,7 @@ class ResourcesTest < ActionController::TestCase
       end
 
       assert_simply_restful_for :product_reviews, controller: "messages", as: "reviews", name_prefix: "product_", path_prefix: "products/1/", options: { product_id: "1" }
-      assert_simply_restful_for :tutor_reviews,controller: "comments", as: "reviews", name_prefix: "tutor_", path_prefix: "tutors/1/", options: { tutor_id: "1" }
+      assert_simply_restful_for :tutor_reviews, controller: "comments", as: "reviews", name_prefix: "tutor_", path_prefix: "tutors/1/", options: { tutor_id: "1" }
     end
   end
 
@@ -1089,7 +1089,7 @@ class ResourcesTest < ActionController::TestCase
     end
   end
 
-  protected
+  private
     def with_restful_routing(*args)
       options = args.extract_options!
       collection_methods = options.delete(:collection)
@@ -1306,7 +1306,7 @@ class ResourcesTest < ActionController::TestCase
     end
 
     def assert_named_route(expected, route, options)
-      actual =  @controller.send(route, options) rescue $!.class.name
+      actual = @controller.send(route, options) rescue $!.class.name
       assert_equal expected, actual, "Error on route: #{route}(#{options.inspect})"
     end
 
diff --git a/actionpack/test/controller/routing_test.rb b/actionpack/test/controller/routing_test.rb
index 7be2ad2b28..56b39510bb 100644
--- a/actionpack/test/controller/routing_test.rb
+++ b/actionpack/test/controller/routing_test.rb
@@ -91,7 +91,7 @@ class LegacyRouteSetTests < ActiveSupport::TestCase
     end
 
     hash = ActiveSupport::JSON.decode get(URI("http://example.org/journey/faithfully-omg"))
-    assert_equal({ "artist"=>"journey", "song"=>"faithfully" }, hash)
+    assert_equal({ "artist" => "journey", "song" => "faithfully" }, hash)
   end
 
   def test_id_with_dash
@@ -103,7 +103,7 @@ class LegacyRouteSetTests < ActiveSupport::TestCase
     end
 
     hash = ActiveSupport::JSON.decode get(URI("http://example.org/journey/faithfully-omg"))
-    assert_equal({ "id"=>"faithfully-omg" }, hash)
+    assert_equal({ "id" => "faithfully-omg" }, hash)
   end
 
   def test_dash_with_custom_regexp
@@ -115,7 +115,7 @@ class LegacyRouteSetTests < ActiveSupport::TestCase
     end
 
     hash = ActiveSupport::JSON.decode get(URI("http://example.org/journey/123-omg"))
-    assert_equal({ "artist"=>"journey", "song"=>"123" }, hash)
+    assert_equal({ "artist" => "journey", "song" => "123" }, hash)
     assert_equal "Not Found", get(URI("http://example.org/journey/faithfully-omg"))
   end
 
@@ -128,7 +128,7 @@ class LegacyRouteSetTests < ActiveSupport::TestCase
     end
 
     hash = ActiveSupport::JSON.decode get(URI("http://example.org/journey/omg-faithfully"))
-    assert_equal({ "artist"=>"journey", "song"=>"faithfully" }, hash)
+    assert_equal({ "artist" => "journey", "song" => "faithfully" }, hash)
   end
 
   def test_pre_dash_with_custom_regexp
@@ -140,7 +140,7 @@ class LegacyRouteSetTests < ActiveSupport::TestCase
     end
 
     hash = ActiveSupport::JSON.decode get(URI("http://example.org/journey/omg-123"))
-    assert_equal({ "artist"=>"journey", "song"=>"123" }, hash)
+    assert_equal({ "artist" => "journey", "song" => "123" }, hash)
     assert_equal "Not Found", get(URI("http://example.org/journey/omg-faithfully"))
   end
 
@@ -1931,7 +1931,7 @@ class RackMountIntegrationTests < ActiveSupport::TestCase
     get "clients" => "projects#index"
 
     get "ignorecase/geocode/:postalcode" => "geocode#show", :postalcode => /hx\d\d-\d[a-z]{2}/i
-    get "extended/geocode/:postalcode" => "geocode#show",:constraints => {
+    get "extended/geocode/:postalcode" => "geocode#show", :constraints => {
                   postalcode: /# Postcode format
                                   \d{5} #Prefix
                                   (-\d{4})? #Suffix
diff --git a/actionpack/test/controller/send_file_test.rb b/actionpack/test/controller/send_file_test.rb
index 8dc565ac8d..9e6b975fe2 100644
--- a/actionpack/test/controller/send_file_test.rb
+++ b/actionpack/test/controller/send_file_test.rb
@@ -180,7 +180,7 @@ class SendFileTest < ActionController::TestCase
       "file.zip" => "application/zip",
       "file.unk" => "application/octet-stream",
       "zip" => "application/octet-stream"
-    }.each do |filename,expected_type|
+    }.each do |filename, expected_type|
       get __method__, params: { filename: filename }
       assert_equal expected_type, response.content_type
     end
@@ -241,10 +241,17 @@ class SendFileTest < ActionController::TestCase
     assert_equal "text/calendar; charset=utf-8", response.headers["Content-Type"]
   end
 
+  def test_send_file_charset_with_type_options_key_without_charset
+    @controller = SendFileWithActionControllerLive.new
+    @controller.options = { type: "image/png" }
+    response = process("file")
+    assert_equal "image/png", response.headers["Content-Type"]
+  end
+
   def test_send_file_charset_with_content_type_options_key
     @controller = SendFileWithActionControllerLive.new
     @controller.options = { content_type: "text/calendar" }
     response = process("file")
-    assert_equal "text/calendar; charset=utf-8", response.headers["Content-Type"]
+    assert_equal "text/calendar", response.headers["Content-Type"]
   end
 end
diff --git a/actionpack/test/controller/test_case_test.rb b/actionpack/test/controller/test_case_test.rb
index 82f42e306f..874f9c3c42 100644
--- a/actionpack/test/controller/test_case_test.rb
+++ b/actionpack/test/controller/test_case_test.rb
@@ -100,11 +100,11 @@ HTML
     end
 
     def test_xml_output
-      response.content_type = "application/xml"
+      response.content_type = params[:response_as]
       render plain: <<XML
 <?xml version="1.0" encoding="UTF-8"?>
 <root>
-  <area>area is an empty tag in HTML, raising an error if not in xml mode</area>
+  <area><p>area is an empty tag in HTML, so it won't contain this content</p></area>
 </root>
 XML
     end
@@ -231,7 +231,7 @@ XML
 
   def test_document_body_and_params_with_post
     post :test_params, params: { id: 1 }
-    assert_equal({ "id"=>"1", "controller"=>"test_case_test/test", "action"=>"test_params" }, ::JSON.parse(@response.body))
+    assert_equal({ "id" => "1", "controller" => "test_case_test/test", "action" => "test_params" }, ::JSON.parse(@response.body))
   end
 
   def test_document_body_with_post
@@ -374,18 +374,18 @@ XML
     assert_equal "OK", @response.body
   end
 
-  def test_should_not_impose_childless_html_tags_in_xml
-    process :test_xml_output
+  def test_should_impose_childless_html_tags_in_html
+    process :test_xml_output, params: { response_as: "text/html" }
 
-    begin
-      $stderr = StringIO.new
-      assert_select "area" #This will cause a warning if content is processed as HTML
-      $stderr.rewind && err = $stderr.read
-    ensure
-      $stderr = STDERR
-    end
+    # <area> auto-closes, so the <p> becomes a sibling
+    assert_select "root > area + p"
+  end
+
+  def test_should_not_impose_childless_html_tags_in_xml
+    process :test_xml_output, params: { response_as: "application/xml" }
 
-    assert err.empty?
+    # <area> is not special, so the <p> is its child
+    assert_select "root > area > p"
   end
 
   def test_assert_generates
@@ -651,7 +651,7 @@ XML
   def test_xhr_with_params
     get :test_params, params: { id: 1 }, xhr: true
 
-    assert_equal({ "id"=>"1", "controller"=>"test_case_test/test", "action"=>"test_params" }, ::JSON.parse(@response.body))
+    assert_equal({ "id" => "1", "controller" => "test_case_test/test", "action" => "test_params" }, ::JSON.parse(@response.body))
   end
 
   def test_xhr_with_session
@@ -753,10 +753,10 @@ XML
 
   def test_multiple_mixed_method_process_should_scrub_rack_input
     post :test_params, params: { id: 1, foo: "an foo" }
-    assert_equal({ "id"=>"1", "foo" => "an foo", "controller"=>"test_case_test/test", "action"=>"test_params" }, ::JSON.parse(@response.body))
+    assert_equal({ "id" => "1", "foo" => "an foo", "controller" => "test_case_test/test", "action" => "test_params" }, ::JSON.parse(@response.body))
 
     get :test_params, params: { bar: "an bar" }
-    assert_equal({ "bar"=>"an bar", "controller"=>"test_case_test/test", "action"=>"test_params" }, ::JSON.parse(@response.body))
+    assert_equal({ "bar" => "an bar", "controller" => "test_case_test/test", "action" => "test_params" }, ::JSON.parse(@response.body))
   end
 
   %w(controller response request).each do |variable|
@@ -781,7 +781,7 @@ XML
   READ_PLAIN = "r:binary"
 
   def test_test_uploaded_file
-    filename = "mona_lisa.jpg"
+    filename = "ruby_on_rails.jpg"
     path = "#{FILES_DIR}/#{filename}"
     content_type = "image/png"
     expected = File.read(path)
@@ -801,13 +801,13 @@ XML
 
   def test_fixture_path_is_accessed_from_self_instead_of_active_support_test_case
     TestCaseTest.stub :fixture_path, FILES_DIR do
-      uploaded_file = fixture_file_upload("/mona_lisa.jpg", "image/png")
-      assert_equal File.open("#{FILES_DIR}/mona_lisa.jpg", READ_PLAIN).read, uploaded_file.read
+      uploaded_file = fixture_file_upload("/ruby_on_rails.jpg", "image/png")
+      assert_equal File.open("#{FILES_DIR}/ruby_on_rails.jpg", READ_PLAIN).read, uploaded_file.read
     end
   end
 
   def test_test_uploaded_file_with_binary
-    filename = "mona_lisa.jpg"
+    filename = "ruby_on_rails.jpg"
     path = "#{FILES_DIR}/#{filename}"
     content_type = "image/png"
 
@@ -819,7 +819,7 @@ XML
   end
 
   def test_fixture_file_upload_with_binary
-    filename = "mona_lisa.jpg"
+    filename = "ruby_on_rails.jpg"
     path = "#{FILES_DIR}/#{filename}"
     content_type = "image/jpg"
 
@@ -831,44 +831,44 @@ XML
   end
 
   def test_fixture_file_upload_should_be_able_access_to_tempfile
-    file = fixture_file_upload(FILES_DIR + "/mona_lisa.jpg", "image/jpg")
+    file = fixture_file_upload(FILES_DIR + "/ruby_on_rails.jpg", "image/jpg")
     assert file.respond_to?(:tempfile), "expected tempfile should respond on fixture file object, got nothing"
   end
 
   def test_fixture_file_upload
     post :test_file_upload,
       params: {
-        file: fixture_file_upload(FILES_DIR + "/mona_lisa.jpg", "image/jpg")
+        file: fixture_file_upload(FILES_DIR + "/ruby_on_rails.jpg", "image/jpg")
       }
-    assert_equal "159528", @response.body
+    assert_equal "45142", @response.body
   end
 
   def test_fixture_file_upload_relative_to_fixture_path
     TestCaseTest.stub :fixture_path, FILES_DIR do
-      uploaded_file = fixture_file_upload("mona_lisa.jpg", "image/jpg")
-      assert_equal File.open("#{FILES_DIR}/mona_lisa.jpg", READ_PLAIN).read, uploaded_file.read
+      uploaded_file = fixture_file_upload("ruby_on_rails.jpg", "image/jpg")
+      assert_equal File.open("#{FILES_DIR}/ruby_on_rails.jpg", READ_PLAIN).read, uploaded_file.read
     end
   end
 
   def test_fixture_file_upload_ignores_fixture_path_given_full_path
     TestCaseTest.stub :fixture_path, File.dirname(__FILE__) do
-      uploaded_file = fixture_file_upload("#{FILES_DIR}/mona_lisa.jpg", "image/jpg")
-      assert_equal File.open("#{FILES_DIR}/mona_lisa.jpg", READ_PLAIN).read, uploaded_file.read
+      uploaded_file = fixture_file_upload("#{FILES_DIR}/ruby_on_rails.jpg", "image/jpg")
+      assert_equal File.open("#{FILES_DIR}/ruby_on_rails.jpg", READ_PLAIN).read, uploaded_file.read
     end
   end
 
   def test_fixture_file_upload_ignores_nil_fixture_path
-    uploaded_file = fixture_file_upload("#{FILES_DIR}/mona_lisa.jpg", "image/jpg")
-    assert_equal File.open("#{FILES_DIR}/mona_lisa.jpg", READ_PLAIN).read, uploaded_file.read
+    uploaded_file = fixture_file_upload("#{FILES_DIR}/ruby_on_rails.jpg", "image/jpg")
+    assert_equal File.open("#{FILES_DIR}/ruby_on_rails.jpg", READ_PLAIN).read, uploaded_file.read
   end
 
   def test_action_dispatch_uploaded_file_upload
-    filename = "mona_lisa.jpg"
+    filename = "ruby_on_rails.jpg"
     path = "#{FILES_DIR}/#{filename}"
     post :test_file_upload, params: {
       file: Rack::Test::UploadedFile.new(path, "image/jpg", true)
     }
-    assert_equal "159528", @response.body
+    assert_equal "45142", @response.body
   end
 
   def test_test_uploaded_file_exception_when_file_doesnt_exist
diff --git a/actionpack/test/controller/url_for_integration_test.rb b/actionpack/test/controller/url_for_integration_test.rb
index c7ea6c5ef6..f640e77b99 100644
--- a/actionpack/test/controller/url_for_integration_test.rb
+++ b/actionpack/test/controller/url_for_integration_test.rb
@@ -43,7 +43,7 @@ module ActionPack
       get "clients" => "projects#index"
 
       get "ignorecase/geocode/:postalcode" => "geocode#show", :postalcode => /hx\d\d-\d[a-z]{2}/i
-      get "extended/geocode/:postalcode" => "geocode#show",:constraints => {
+      get "extended/geocode/:postalcode" => "geocode#show", :constraints => {
         postalcode: /# Postcode format
         \d{5} #Prefix
         (-\d{4})? #Suffix
@@ -73,99 +73,99 @@ module ActionPack
     end
 
     [
-      ["/admin/users",[ { use_route: "admin_users" }]],
-      ["/admin/users",[ { controller: "admin/users" }]],
-      ["/admin/users",[ { controller: "admin/users", action: "index" }]],
-      ["/admin/users",[ { action: "index" }, { controller: "admin/users", action: "index" }, "/admin/users"]],
-      ["/admin/users",[ { controller: "users", action: "index" }, { controller: "admin/accounts", action: "show", id: "1" }, "/admin/accounts/show/1"]],
-      ["/people",[      { controller: "/people", action: "index" }, { controller: "admin/accounts", action: "foo", id: "bar" }, "/admin/accounts/foo/bar"]],
-
-      ["/admin/posts",[     { controller: "admin/posts" }]],
-      ["/admin/posts/new",[ { controller: "admin/posts", action: "new" }]],
-
-      ["/blog/2009",[     { controller: "posts", action: "show_date", year: 2009 }]],
-      ["/blog/2009/1",[   { controller: "posts", action: "show_date", year: 2009, month: 1 }]],
-      ["/blog/2009/1/1",[ { controller: "posts", action: "show_date", year: 2009, month: 1, day: 1 }]],
-
-      ["/archive/2010",[ { controller: "archive", action: "index", year: "2010" }]],
-      ["/archive",[      { controller: "archive", action: "index" }]],
-      ["/archive?year=january",[ { controller: "archive", action: "index", year: "january" }]],
-
-      ["/people",[ { controller: "people", action: "index" }]],
-      ["/people",[ { action: "index" }, { controller: "people", action: "index" }, "/people"]],
-      ["/people",[ { action: "index" }, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
-      ["/people",[ { controller: "people", action: "index" }, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
-      ["/people",[ {}, { controller: "people", action: "index" }, "/people"]],
-      ["/people/1",[   { controller: "people", action: "show" }, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
-      ["/people/new",[ { use_route: "new_person" }]],
-      ["/people/new",[ { controller: "people", action: "new" }]],
-      ["/people/1",[   { use_route: "person", id: "1" }]],
-      ["/people/1",[   { controller: "people", action: "show", id: "1" }]],
-      ["/people/1.xml",[ { controller: "people", action: "show", id: "1", format: "xml" }]],
-      ["/people/1",[ { controller: "people", action: "show", id: 1 }]],
-      ["/people/1",[ { controller: "people", action: "show", id: Model.new("1") }]],
-      ["/people/1",[ { action: "show", id: "1" }, { controller: "people", action: "index" }, "/people"]],
-      ["/people/1",[ { action: "show", id: 1 }, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
-      ["/people",[   { controller: "people", action: "index" }, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
-      ["/people/1",[ {}, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
-      ["/people/1",[ { controller: "people", action: "show" }, { controller: "people", action: "index", id: "1" }, "/people/index/1"]],
-      ["/people/1/edit",[     { controller: "people", action: "edit", id: "1" }]],
-      ["/people/1/edit.xml",[ { controller: "people", action: "edit", id: "1", format: "xml" }]],
-      ["/people/1/edit",[     { use_route: "edit_person", id: "1" }]],
-      ["/people/1?legacy=true",[ { controller: "people", action: "show", id: "1", legacy: "true" }]],
-      ["/people?legacy=true",[   { controller: "people", action: "index", legacy: "true" }]],
-
-      ["/id_default/2",[ { controller: "foo", action: "id_default", id: "2" }]],
-      ["/id_default",[   { controller: "foo", action: "id_default", id: "1" }]],
-      ["/id_default",[   { controller: "foo", action: "id_default", id: 1 }]],
-      ["/id_default",[   { controller: "foo", action: "id_default" }]],
-      ["/optional/bar",[ { controller: "posts", action: "index", optional: "bar" }]],
-      ["/posts",[ { controller: "posts", action: "index" }]],
-
-      ["/project",[    { controller: "project", action: "index" }]],
-      ["/projects/1",[ { controller: "project", action: "index", project_id: "1" }]],
-      ["/projects/1",[ { controller: "project", action: "index" }, { project_id: "1", controller: "project", action: "index" }, "/projects/1"]],
-      ["/projects/1",[ { use_route: "project", controller: "project", action: "index", project_id: "1" }]],
-      ["/projects/1",[ { use_route: "project", controller: "project", action: "index" }, { controller: "project", action: "index", project_id: "1" }, "/projects/1"]],
-
-      ["/clients",[ { controller: "projects", action: "index" }]],
-      ["/clients?project_id=1",[ { controller: "projects", action: "index", project_id: "1" }]],
-      ["/clients",[ { controller: "projects", action: "index" }, { project_id: "1", controller: "project", action: "index" }, "/projects/1"]],
-
-      ["/comment/20",[   { id: 20 }, { controller: "comments", action: "show" }, "/comments/show"]],
-      ["/comment/20",[   { controller: "comments", id: 20, action: "show" }]],
-      ["/comments/boo",[ { controller: "comments", action: "boo" }]],
-
-      ["/ws/posts/show/1",[ { controller: "posts", action: "show", id: "1", ws: true }]],
-      ["/ws/posts",[        { controller: "posts", action: "index", ws: true }]],
-
-      ["/account",[         { controller: "account", action: "subscription" }]],
-      ["/account/billing",[ { controller: "account", action: "billing" }]],
-
-      ["/pages/1/notes/show/1",[ { page_id: "1", controller: "notes", action: "show", id: "1" }]],
-      ["/pages/1/notes/list",[   { page_id: "1", controller: "notes", action: "list" }]],
-      ["/pages/1/notes",[ { page_id: "1", controller: "notes", action: "index" }]],
-      ["/pages/1/notes",[ { page_id: "1", controller: "notes" }]],
-      ["/notes",[         { page_id: nil, controller: "notes" }]],
-      ["/notes",[         { controller: "notes" }]],
-      ["/notes/print",[   { controller: "notes", action: "print" }]],
-      ["/notes/print",[   {}, { controller: "notes", action: "print" }, "/notes/print"]],
-
-      ["/notes/index/1",[ { controller: "notes" }, { controller: "notes", action: "index", id: "1" }, "/notes/index/1"]],
-      ["/notes/index/1",[ { controller: "notes" }, { controller: "notes", id: "1", action: "index" }, "/notes/index/1"]],
-      ["/notes/index/1",[ { action: "index" }, { controller: "notes", id: "1", action: "index" }, "/notes/index/1"]],
-      ["/notes/index/1",[ {}, { controller: "notes", id: "1", action: "index" }, "/notes/index/1"]],
-      ["/notes/show/1",[  {}, { controller: "notes", action: "show", id: "1" }, "/notes/show/1"]],
-      ["/posts",[      { controller: "posts" }, { controller: "notes", action: "show", id: "1" }, "/notes/show/1"]],
-      ["/notes/list",[ { action: "list" }, { controller: "notes", action: "show", id: "1" }, "/notes/show/1"]],
-
-      ["/posts/ping",[    { controller: "posts", action: "ping" }]],
-      ["/posts/show/1",[  { controller: "posts", action: "show", id: "1" }]],
-      ["/posts/show/1",[  { controller: "posts", action: "show", id: "1", format: "" }]],
-      ["/posts",[         { controller: "posts" }]],
-      ["/posts",[         { controller: "posts", action: "index" }]],
-      ["/posts/create",[  { action: "create" }, { day: nil, month: nil, controller: "posts", action: "show_date" }, "/blog"]],
-      ["/posts?foo=bar",[ { controller: "posts", foo: "bar" }]],
+      ["/admin/users", [ { use_route: "admin_users" }]],
+      ["/admin/users", [ { controller: "admin/users" }]],
+      ["/admin/users", [ { controller: "admin/users", action: "index" }]],
+      ["/admin/users", [ { action: "index" }, { controller: "admin/users", action: "index" }, "/admin/users"]],
+      ["/admin/users", [ { controller: "users", action: "index" }, { controller: "admin/accounts", action: "show", id: "1" }, "/admin/accounts/show/1"]],
+      ["/people", [      { controller: "/people", action: "index" }, { controller: "admin/accounts", action: "foo", id: "bar" }, "/admin/accounts/foo/bar"]],
+
+      ["/admin/posts", [     { controller: "admin/posts" }]],
+      ["/admin/posts/new", [ { controller: "admin/posts", action: "new" }]],
+
+      ["/blog/2009", [     { controller: "posts", action: "show_date", year: 2009 }]],
+      ["/blog/2009/1", [   { controller: "posts", action: "show_date", year: 2009, month: 1 }]],
+      ["/blog/2009/1/1", [ { controller: "posts", action: "show_date", year: 2009, month: 1, day: 1 }]],
+
+      ["/archive/2010", [ { controller: "archive", action: "index", year: "2010" }]],
+      ["/archive", [      { controller: "archive", action: "index" }]],
+      ["/archive?year=january", [ { controller: "archive", action: "index", year: "january" }]],
+
+      ["/people", [ { controller: "people", action: "index" }]],
+      ["/people", [ { action: "index" }, { controller: "people", action: "index" }, "/people"]],
+      ["/people", [ { action: "index" }, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
+      ["/people", [ { controller: "people", action: "index" }, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
+      ["/people", [ {}, { controller: "people", action: "index" }, "/people"]],
+      ["/people/1", [   { controller: "people", action: "show" }, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
+      ["/people/new", [ { use_route: "new_person" }]],
+      ["/people/new", [ { controller: "people", action: "new" }]],
+      ["/people/1", [   { use_route: "person", id: "1" }]],
+      ["/people/1", [   { controller: "people", action: "show", id: "1" }]],
+      ["/people/1.xml", [ { controller: "people", action: "show", id: "1", format: "xml" }]],
+      ["/people/1", [ { controller: "people", action: "show", id: 1 }]],
+      ["/people/1", [ { controller: "people", action: "show", id: Model.new("1") }]],
+      ["/people/1", [ { action: "show", id: "1" }, { controller: "people", action: "index" }, "/people"]],
+      ["/people/1", [ { action: "show", id: 1 }, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
+      ["/people", [   { controller: "people", action: "index" }, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
+      ["/people/1", [ {}, { controller: "people", action: "show", id: "1" }, "/people/show/1"]],
+      ["/people/1", [ { controller: "people", action: "show" }, { controller: "people", action: "index", id: "1" }, "/people/index/1"]],
+      ["/people/1/edit", [     { controller: "people", action: "edit", id: "1" }]],
+      ["/people/1/edit.xml", [ { controller: "people", action: "edit", id: "1", format: "xml" }]],
+      ["/people/1/edit", [     { use_route: "edit_person", id: "1" }]],
+      ["/people/1?legacy=true", [ { controller: "people", action: "show", id: "1", legacy: "true" }]],
+      ["/people?legacy=true", [   { controller: "people", action: "index", legacy: "true" }]],
+
+      ["/id_default/2", [ { controller: "foo", action: "id_default", id: "2" }]],
+      ["/id_default", [   { controller: "foo", action: "id_default", id: "1" }]],
+      ["/id_default", [   { controller: "foo", action: "id_default", id: 1 }]],
+      ["/id_default", [   { controller: "foo", action: "id_default" }]],
+      ["/optional/bar", [ { controller: "posts", action: "index", optional: "bar" }]],
+      ["/posts", [ { controller: "posts", action: "index" }]],
+
+      ["/project", [    { controller: "project", action: "index" }]],
+      ["/projects/1", [ { controller: "project", action: "index", project_id: "1" }]],
+      ["/projects/1", [ { controller: "project", action: "index" }, { project_id: "1", controller: "project", action: "index" }, "/projects/1"]],
+      ["/projects/1", [ { use_route: "project", controller: "project", action: "index", project_id: "1" }]],
+      ["/projects/1", [ { use_route: "project", controller: "project", action: "index" }, { controller: "project", action: "index", project_id: "1" }, "/projects/1"]],
+
+      ["/clients", [ { controller: "projects", action: "index" }]],
+      ["/clients?project_id=1", [ { controller: "projects", action: "index", project_id: "1" }]],
+      ["/clients", [ { controller: "projects", action: "index" }, { project_id: "1", controller: "project", action: "index" }, "/projects/1"]],
+
+      ["/comment/20", [   { id: 20 }, { controller: "comments", action: "show" }, "/comments/show"]],
+      ["/comment/20", [   { controller: "comments", id: 20, action: "show" }]],
+      ["/comments/boo", [ { controller: "comments", action: "boo" }]],
+
+      ["/ws/posts/show/1", [ { controller: "posts", action: "show", id: "1", ws: true }]],
+      ["/ws/posts", [        { controller: "posts", action: "index", ws: true }]],
+
+      ["/account", [         { controller: "account", action: "subscription" }]],
+      ["/account/billing", [ { controller: "account", action: "billing" }]],
+
+      ["/pages/1/notes/show/1", [ { page_id: "1", controller: "notes", action: "show", id: "1" }]],
+      ["/pages/1/notes/list", [   { page_id: "1", controller: "notes", action: "list" }]],
+      ["/pages/1/notes", [ { page_id: "1", controller: "notes", action: "index" }]],
+      ["/pages/1/notes", [ { page_id: "1", controller: "notes" }]],
+      ["/notes", [         { page_id: nil, controller: "notes" }]],
+      ["/notes", [         { controller: "notes" }]],
+      ["/notes/print", [   { controller: "notes", action: "print" }]],
+      ["/notes/print", [   {}, { controller: "notes", action: "print" }, "/notes/print"]],
+
+      ["/notes/index/1", [ { controller: "notes" }, { controller: "notes", action: "index", id: "1" }, "/notes/index/1"]],
+      ["/notes/index/1", [ { controller: "notes" }, { controller: "notes", id: "1", action: "index" }, "/notes/index/1"]],
+      ["/notes/index/1", [ { action: "index" }, { controller: "notes", id: "1", action: "index" }, "/notes/index/1"]],
+      ["/notes/index/1", [ {}, { controller: "notes", id: "1", action: "index" }, "/notes/index/1"]],
+      ["/notes/show/1", [  {}, { controller: "notes", action: "show", id: "1" }, "/notes/show/1"]],
+      ["/posts", [      { controller: "posts" }, { controller: "notes", action: "show", id: "1" }, "/notes/show/1"]],
+      ["/notes/list", [ { action: "list" }, { controller: "notes", action: "show", id: "1" }, "/notes/show/1"]],
+
+      ["/posts/ping", [    { controller: "posts", action: "ping" }]],
+      ["/posts/show/1", [  { controller: "posts", action: "show", id: "1" }]],
+      ["/posts/show/1", [  { controller: "posts", action: "show", id: "1", format: "" }]],
+      ["/posts", [         { controller: "posts" }]],
+      ["/posts", [         { controller: "posts", action: "index" }]],
+      ["/posts/create", [  { action: "create" }, { day: nil, month: nil, controller: "posts", action: "show_date" }, "/blog"]],
+      ["/posts?foo=bar", [ { controller: "posts", foo: "bar" }]],
       ["/posts?foo%5B%5D=bar&foo%5B%5D=baz", [{ controller: "posts", foo: ["bar", "baz"] }]],
       ["/posts?page=2",  [{ controller: "posts", page: 2 }]],
       ["/posts?q%5Bfoo%5D%5Ba%5D=b", [{ controller: "posts", q: { foo: { a: "b" } } }]],
diff --git a/actionpack/test/controller/url_for_test.rb b/actionpack/test/controller/url_for_test.rb
index 8d7190365d..4b6f33c545 100644
--- a/actionpack/test/controller/url_for_test.rb
+++ b/actionpack/test/controller/url_for_test.rb
@@ -223,13 +223,13 @@ module AbstractController
       def test_trailing_slash
         add_host!
         options = { controller: "foo", trailing_slash: true, action: "bar", id: "33" }
-        assert_equal("http://www.basecamphq.com/foo/bar/33/", W.new.url_for(options) )
+        assert_equal("http://www.basecamphq.com/foo/bar/33/", W.new.url_for(options))
       end
 
       def test_trailing_slash_with_protocol
         add_host!
-        options = { trailing_slash: true,protocol: "https", controller: "foo", action: "bar", id: "33" }
-        assert_equal("https://www.basecamphq.com/foo/bar/33/", W.new.url_for(options) )
+        options = { trailing_slash: true, protocol: "https", controller: "foo", action: "bar", id: "33" }
+        assert_equal("https://www.basecamphq.com/foo/bar/33/", W.new.url_for(options))
         assert_equal "https://www.basecamphq.com/foo/bar/33/?query=string", W.new.url_for(options.merge(query: "string"))
       end
 
@@ -238,7 +238,7 @@ module AbstractController
         assert_equal "/foo/", W.new.url_for(options.merge(only_path: true))
         options.update(action: "bar", id: "33")
         assert_equal "/foo/bar/33/", W.new.url_for(options.merge(only_path: true))
-        assert_equal "/foo/bar/33/?query=string", W.new.url_for(options.merge(query: "string",only_path: true))
+        assert_equal "/foo/bar/33/?query=string", W.new.url_for(options.merge(query: "string", only_path: true))
       end
 
       def test_trailing_slash_with_anchor
@@ -423,7 +423,7 @@ module AbstractController
         first_class.default_url_options[:host] = first_host
         second_class.default_url_options[:host] = second_host
 
-        assert_equal  first_host, first_class.default_url_options[:host]
+        assert_equal first_host, first_class.default_url_options[:host]
         assert_equal second_host, second_class.default_url_options[:host]
       end
 
diff --git a/actionpack/test/dispatch/cookies_test.rb b/actionpack/test/dispatch/cookies_test.rb
index 6dcd62572a..664faa31bb 100644
--- a/actionpack/test/dispatch/cookies_test.rb
+++ b/actionpack/test/dispatch/cookies_test.rb
@@ -43,7 +43,7 @@ class CookieJarTest < ActiveSupport::TestCase
   def test_each
     request.cookie_jar["foo"] = :bar
     list = []
-    request.cookie_jar.each do |k,v|
+    request.cookie_jar.each do |k, v|
       list << [k, v]
     end
 
@@ -52,7 +52,7 @@ class CookieJarTest < ActiveSupport::TestCase
 
   def test_enumerable
     request.cookie_jar["foo"] = :bar
-    actual = request.cookie_jar.map { |k,v| [k.to_s, v.to_s] }
+    actual = request.cookie_jar.map { |k, v| [k.to_s, v.to_s] }
     assert_equal [["foo", "bar"]], actual
   end
 
@@ -95,17 +95,17 @@ class CookiesTest < ActionController::TestCase
     end
 
     def authenticate_for_fourteen_days
-      cookies["user_name"] = { "value" => "david", "expires" => Time.utc(2005, 10, 10,5) }
+      cookies["user_name"] = { "value" => "david", "expires" => Time.utc(2005, 10, 10, 5) }
       head :ok
     end
 
     def authenticate_for_fourteen_days_with_symbols
-      cookies[:user_name] = { value: "david", expires: Time.utc(2005, 10, 10,5) }
+      cookies[:user_name] = { value: "david", expires: Time.utc(2005, 10, 10, 5) }
       head :ok
     end
 
     def set_multiple_cookies
-      cookies["user_name"] = { "value" => "david", "expires" => Time.utc(2005, 10, 10,5) }
+      cookies["user_name"] = { "value" => "david", "expires" => Time.utc(2005, 10, 10, 5) }
       cookies["login"]     = "XJ-122"
       head :ok
     end
@@ -205,7 +205,7 @@ class CookiesTest < ActionController::TestCase
 
     def delete_and_set_cookie
       cookies.delete :user_name
-      cookies[:user_name] = { value: "david", expires: Time.utc(2005, 10, 10,5) }
+      cookies[:user_name] = { value: "david", expires: Time.utc(2005, 10, 10, 5) }
       head :ok
     end
 
@@ -272,6 +272,10 @@ class CookiesTest < ActionController::TestCase
     def noop
       head :ok
     end
+
+    def encrypted_cookie
+      cookies.encrypted["foo"]
+    end
   end
 
   tests TestController
@@ -940,8 +944,8 @@ class CookiesTest < ActionController::TestCase
     @request.headers["Cookie"] = "user_id=45"
     get :get_signed_cookie
 
-    assert_equal nil, @controller.send(:cookies).signed[:user_id]
-    assert_equal nil, @response.cookies["user_id"]
+    assert_nil @controller.send(:cookies).signed[:user_id]
+    assert_nil @response.cookies["user_id"]
   end
 
   def test_legacy_signed_cookie_is_treated_as_nil_by_encrypted_cookie_jar_if_tampered
@@ -951,8 +955,8 @@ class CookiesTest < ActionController::TestCase
     @request.headers["Cookie"] = "foo=baz"
     get :get_encrypted_cookie
 
-    assert_equal nil, @controller.send(:cookies).encrypted[:foo]
-    assert_equal nil, @response.cookies["foo"]
+    assert_nil @controller.send(:cookies).encrypted[:foo]
+    assert_nil @response.cookies["foo"]
   end
 
   def test_cookie_with_all_domain_option
@@ -1189,6 +1193,12 @@ class CookiesTest < ActionController::TestCase
     assert_equal "david", cookies[:user_name]
   end
 
+  def test_cookies_are_not_cleared
+    cookies.encrypted["foo"] = "bar"
+    get :noop
+    assert_equal "bar", @controller.encrypted_cookie
+  end
+
   private
     def assert_cookie_header(expected)
       header = @response.headers["Set-Cookie"]
diff --git a/actionpack/test/dispatch/debug_exceptions_test.rb b/actionpack/test/dispatch/debug_exceptions_test.rb
index 2c5e09e283..ea477e8908 100644
--- a/actionpack/test/dispatch/debug_exceptions_test.rb
+++ b/actionpack/test/dispatch/debug_exceptions_test.rb
@@ -287,7 +287,7 @@ class DebugExceptionsTest < ActionDispatch::IntegrationTest
   test "does not show filtered parameters" do
     @app = DevelopmentApp
 
-    get "/", params: { "foo"=>"bar" }, headers: { "action_dispatch.show_exceptions" => true,
+    get "/", params: { "foo" => "bar" }, headers: { "action_dispatch.show_exceptions" => true,
       "action_dispatch.parameter_filter" => [:foo] }
     assert_response 500
     assert_match("&quot;foo&quot;=&gt;&quot;[FILTERED]&quot;", body)
@@ -384,6 +384,23 @@ class DebugExceptionsTest < ActionDispatch::IntegrationTest
     end
   end
 
+  test "logs with non active support loggers" do
+    @app = DevelopmentApp
+    io = StringIO.new
+    logger = Logger.new(io)
+
+    _old, ActionView::Base.logger = ActionView::Base.logger, logger
+    begin
+      assert_nothing_raised do
+        get "/", headers: { "action_dispatch.show_exceptions" => true, "action_dispatch.logger" => logger }
+      end
+    ensure
+      ActionView::Base.logger = _old
+    end
+
+    assert_match(/puke/, io.rewind && io.read)
+  end
+
   test "uses backtrace cleaner from env" do
     @app = DevelopmentApp
     backtrace_cleaner = ActiveSupport::BacktraceCleaner.new
diff --git a/actionpack/test/dispatch/header_test.rb b/actionpack/test/dispatch/header_test.rb
index 6febd5cb68..958450072e 100644
--- a/actionpack/test/dispatch/header_test.rb
+++ b/actionpack/test/dispatch/header_test.rb
@@ -155,8 +155,8 @@ class HeaderTest < ActiveSupport::TestCase
     headers = make_headers(env)
     headers["Referer"] = "http://example.com/"
     headers.merge! "CONTENT_TYPE" => "text/plain"
-    assert_equal({ "HTTP_REFERER"=>"http://example.com/",
-                  "CONTENT_TYPE"=>"text/plain" }, env)
+    assert_equal({ "HTTP_REFERER" => "http://example.com/",
+                  "CONTENT_TYPE" => "text/plain" }, env)
   end
 
   test "fetch exception" do
diff --git a/actionpack/test/dispatch/mime_type_test.rb b/actionpack/test/dispatch/mime_type_test.rb
index e558efb88d..2ca03c535a 100644
--- a/actionpack/test/dispatch/mime_type_test.rb
+++ b/actionpack/test/dispatch/mime_type_test.rb
@@ -89,7 +89,7 @@ class MimeTypeTest < ActiveSupport::TestCase
   #  (compatible; MSIE 6.0; Windows NT 5.1; SV1; .NET CLR 1.1.4322; InfoPath.1)
   test "parse other broken acceptlines" do
     accept = "image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, application/x-shockwave-flash, application/vnd.ms-excel, application/vnd.ms-powerpoint, application/msword,  , pronto/1.00.00, sslvpn/1.00.00.00, */*"
-    expect = ["image/gif", "image/x-xbitmap", "image/jpeg","image/pjpeg", "application/x-shockwave-flash", "application/vnd.ms-excel", "application/vnd.ms-powerpoint", "application/msword", "pronto/1.00.00", "sslvpn/1.00.00.00", "*/*"]
+    expect = ["image/gif", "image/x-xbitmap", "image/jpeg", "image/pjpeg", "application/x-shockwave-flash", "application/vnd.ms-excel", "application/vnd.ms-powerpoint", "application/msword", "pronto/1.00.00", "sslvpn/1.00.00.00", "*/*"]
     assert_equal expect.map(&:to_s), Mime::Type.parse(accept).map(&:to_s)
   end
 
diff --git a/actionpack/test/dispatch/reloader_test.rb b/actionpack/test/dispatch/reloader_test.rb
index e74b8e40fd..db68549b84 100644
--- a/actionpack/test/dispatch/reloader_test.rb
+++ b/actionpack/test/dispatch/reloader_test.rb
@@ -178,7 +178,7 @@ class ReloaderTest < ActiveSupport::TestCase
   def test_cleanup_callbacks_are_called_on_exceptions
     cleaned = false
     assert_deprecated do
-      Reloader.to_cleanup { cleaned  = true }
+      Reloader.to_cleanup { cleaned = true }
     end
 
     begin
diff --git a/actionpack/test/dispatch/request/multipart_params_parsing_test.rb b/actionpack/test/dispatch/request/multipart_params_parsing_test.rb
index e572c722a0..01c5ff1429 100644
--- a/actionpack/test/dispatch/request/multipart_params_parsing_test.rb
+++ b/actionpack/test/dispatch/request/multipart_params_parsing_test.rb
@@ -129,7 +129,7 @@ class MultipartParamsParsingTest < ActionDispatch::IntegrationTest
     params = parse_multipart("none")
     assert_equal %w(submit-name), params.keys.sort
     assert_equal "Larry", params["submit-name"]
-    assert_equal nil, params["files"]
+    assert_nil params["files"]
   end
 
   test "parses empty upload file" do
@@ -142,7 +142,7 @@ class MultipartParamsParsingTest < ActionDispatch::IntegrationTest
 
   test "uploads and reads binary file" do
     with_test_routing do
-      fixture = FIXTURE_PATH + "/mona_lisa.jpg"
+      fixture = FIXTURE_PATH + "/ruby_on_rails.jpg"
       params = { uploaded_data: fixture_file_upload(fixture, "image/jpg") }
       post "/read", params: params
     end
diff --git a/actionpack/test/dispatch/request/query_string_parsing_test.rb b/actionpack/test/dispatch/request/query_string_parsing_test.rb
index 5c992be216..2499c33cef 100644
--- a/actionpack/test/dispatch/request/query_string_parsing_test.rb
+++ b/actionpack/test/dispatch/request/query_string_parsing_test.rb
@@ -97,7 +97,7 @@ class QueryStringParsingTest < ActionDispatch::IntegrationTest
     assert_parses({ "action" => { "foo" => { "bar" => nil } } }, "action[foo][bar]")
     assert_parses({ "action" => { "foo" => { "bar" => [] } } }, "action[foo][bar][]")
     assert_parses({ "action" => { "foo" => [] } }, "action[foo][]")
-    assert_parses({ "action"=>{ "foo"=>[{ "bar"=>nil }] } }, "action[foo][][bar]")
+    assert_parses({ "action" => { "foo" => [{ "bar" => nil }] } }, "action[foo][][bar]")
   end
 
   def test_array_parses_without_nil
@@ -114,7 +114,7 @@ class QueryStringParsingTest < ActionDispatch::IntegrationTest
       assert_parses({ "action" => { "foo" => { "bar" => [nil] } } }, "action[foo][bar][]")
       assert_parses({ "action" => { "foo" => [nil] } }, "action[foo][]")
       assert_parses({ "action" => { "foo" => [{ "bar" => nil }] } }, "action[foo][][bar]")
-      assert_parses({ "action" => ["1",nil] }, "action[]=1&action[]")
+      assert_parses({ "action" => ["1", nil] }, "action[]=1&action[]")
     ensure
       ActionDispatch::Request::Utils.perform_deep_munge = old_perform_deep_munge
     end
diff --git a/actionpack/test/dispatch/request/url_encoded_params_parsing_test.rb b/actionpack/test/dispatch/request/url_encoded_params_parsing_test.rb
index 5c7558e48d..1169bf0cdb 100644
--- a/actionpack/test/dispatch/request/url_encoded_params_parsing_test.rb
+++ b/actionpack/test/dispatch/request/url_encoded_params_parsing_test.rb
@@ -55,7 +55,7 @@ class UrlEncodedParamsParsingTest < ActionDispatch::IntegrationTest
       "products[second]=Pc",
       "=Save"
     ].join("&")
-    expected =  {
+    expected = {
       "customers" => {
         "boston" => {
           "first" => {
diff --git a/actionpack/test/dispatch/request_test.rb b/actionpack/test/dispatch/request_test.rb
index 13a87b8976..e11b93b4f0 100644
--- a/actionpack/test/dispatch/request_test.rb
+++ b/actionpack/test/dispatch/request_test.rb
@@ -18,7 +18,7 @@ class BaseRequestTest < ActiveSupport::TestCase
     ActionDispatch::Http::URL.url_for(options)
   end
 
-  protected
+  private
     def stub_request(env = {})
       ip_spoofing_check = env.key?(:ip_spoofing_check) ? env.delete(:ip_spoofing_check) : true
       @trusted_proxies ||= nil
@@ -94,13 +94,13 @@ class RequestIP < BaseRequestTest
     assert_equal "3.4.5.6", request.remote_ip
 
     request = stub_request "HTTP_X_FORWARDED_FOR" => "unknown,192.168.0.1"
-    assert_equal nil, request.remote_ip
+    assert_nil request.remote_ip
 
     request = stub_request "HTTP_X_FORWARDED_FOR" => "9.9.9.9, 3.4.5.6, 172.31.4.4, 10.0.0.1"
     assert_equal "3.4.5.6", request.remote_ip
 
     request = stub_request "HTTP_X_FORWARDED_FOR" => "not_ip_address"
-    assert_equal nil, request.remote_ip
+    assert_nil request.remote_ip
   end
 
   test "remote ip spoof detection" do
@@ -154,7 +154,7 @@ class RequestIP < BaseRequestTest
     assert_equal "fe80:0000:0000:0000:0202:b3ff:fe1e:8329", request.remote_ip
 
     request = stub_request "HTTP_X_FORWARDED_FOR" => "unknown,::1"
-    assert_equal nil, request.remote_ip
+    assert_nil request.remote_ip
 
     request = stub_request "HTTP_X_FORWARDED_FOR" => "2001:0db8:85a3:0000:0000:8a2e:0370:7334, fe80:0000:0000:0000:0202:b3ff:fe1e:8329, ::1, fc00::, fc01::, fdff"
     assert_equal "fe80:0000:0000:0000:0202:b3ff:fe1e:8329", request.remote_ip
@@ -163,7 +163,7 @@ class RequestIP < BaseRequestTest
     assert_equal "FE00::", request.remote_ip
 
     request = stub_request "HTTP_X_FORWARDED_FOR" => "not_ip_address"
-    assert_equal nil, request.remote_ip
+    assert_nil request.remote_ip
   end
 
   test "remote ip v6 spoof detection" do
@@ -200,7 +200,7 @@ class RequestIP < BaseRequestTest
     assert_equal "3.4.5.6", request.remote_ip
 
     request = stub_request "HTTP_X_FORWARDED_FOR" => "67.205.106.73,unknown"
-    assert_equal nil, request.remote_ip
+    assert_nil request.remote_ip
 
     request = stub_request "HTTP_X_FORWARDED_FOR" => "9.9.9.9, 3.4.5.6, 10.0.0.1, 67.205.106.73"
     assert_equal "3.4.5.6", request.remote_ip
@@ -222,7 +222,7 @@ class RequestIP < BaseRequestTest
     assert_equal "::1", request.remote_ip
 
     request = stub_request "HTTP_X_FORWARDED_FOR" => "unknown,fe80:0000:0000:0000:0202:b3ff:fe1e:8329"
-    assert_equal nil, request.remote_ip
+    assert_nil request.remote_ip
 
     request = stub_request "HTTP_X_FORWARDED_FOR" => "fe80:0000:0000:0000:0202:b3ff:fe1e:8329,2001:0db8:85a3:0000:0000:8a2e:0370:7334"
     assert_equal "2001:0db8:85a3:0000:0000:8a2e:0370:7334", request.remote_ip
@@ -345,7 +345,7 @@ class RequestPort < BaseRequestTest
 
   test "optional port" do
     request = stub_request "HTTP_HOST" => "www.example.org:80"
-    assert_equal nil, request.optional_port
+    assert_nil request.optional_port
 
     request = stub_request "HTTP_HOST" => "www.example.org:8080"
     assert_equal 8080, request.optional_port
@@ -537,7 +537,7 @@ class RequestCGI < BaseRequestTest
 
     assert_equal "Basic", request.auth_type
     assert_equal 0, request.content_length
-    assert_equal nil, request.content_mime_type
+    assert_nil request.content_mime_type
     assert_equal "CGI/1.1", request.gateway_interface
     assert_equal "*/*", request.accept
     assert_equal "UTF-8", request.accept_charset
@@ -581,7 +581,7 @@ class RequestCookie < BaseRequestTest
 
     # some Nokia phone browsers omit the space after the semicolon separator.
     # some developers have grown accustomed to using comma in cookie values.
-    request = stub_request("HTTP_COOKIE"=>"_session_id=c84ace847,96670c052c6ceb2451fb0f2;is_admin=yes")
+    request = stub_request("HTTP_COOKIE" => "_session_id=c84ace847,96670c052c6ceb2451fb0f2;is_admin=yes")
     assert_equal "c84ace847", request.cookies["_session_id"], request.cookies.inspect
     assert_equal "yes", request.cookies["is_admin"], request.cookies.inspect
   end
@@ -596,7 +596,7 @@ class RequestParamsParsing < BaseRequestTest
       "rack.input" => StringIO.new("flamenco=love")
     )
 
-    assert_equal({ "flamenco"=> "love" }, request.request_parameters)
+    assert_equal({ "flamenco" => "love" }, request.request_parameters)
   end
 
   test "doesnt interpret request uri as query string when missing" do
@@ -774,8 +774,8 @@ class RequestMethod < BaseRequestTest
     ensure
       # Reset original acronym set
       ActiveSupport::Inflector.inflections do |inflect|
-        inflect.send(:instance_variable_set,"@acronyms",existing_acrnoyms)
-        inflect.send(:instance_variable_set,"@acronym_regex",existing_acrnoym_regex)
+        inflect.send(:instance_variable_set, "@acronyms", existing_acrnoyms)
+        inflect.send(:instance_variable_set, "@acronym_regex", existing_acrnoym_regex)
       end
     end
   end
@@ -957,7 +957,7 @@ class RequestMimeType < BaseRequestTest
   end
 
   test "no content type" do
-    assert_equal nil, stub_request.content_mime_type
+    assert_nil stub_request.content_mime_type
   end
 
   test "content type is XML" do
@@ -978,7 +978,7 @@ class RequestMimeType < BaseRequestTest
       "HTTP_X_REQUESTED_WITH" => "XMLHttpRequest"
     )
 
-    assert_equal nil, request.negotiate_mime([Mime[:xml], Mime[:json]])
+    assert_nil request.negotiate_mime([Mime[:xml], Mime[:json]])
     assert_equal Mime[:html], request.negotiate_mime([Mime[:xml], Mime[:html]])
     assert_equal Mime[:html], request.negotiate_mime([Mime[:xml], Mime::ALL])
   end
@@ -1072,14 +1072,14 @@ end
 class RequestParameterFilter < BaseRequestTest
   test "process parameter filter" do
     test_hashes = [
-    [{ "foo"=>"bar" },{ "foo"=>"bar" },%w'food'],
-    [{ "foo"=>"bar" },{ "foo"=>"[FILTERED]" },%w'foo'],
-    [{ "foo"=>"bar", "bar"=>"foo" },{ "foo"=>"[FILTERED]", "bar"=>"foo" },%w'foo baz'],
-    [{ "foo"=>"bar", "baz"=>"foo" },{ "foo"=>"[FILTERED]", "baz"=>"[FILTERED]" },%w'foo baz'],
-    [{ "bar"=>{ "foo"=>"bar","bar"=>"foo" } },{ "bar"=>{ "foo"=>"[FILTERED]","bar"=>"foo" } },%w'fo'],
-    [{ "foo"=>{ "foo"=>"bar","bar"=>"foo" } },{ "foo"=>"[FILTERED]" },%w'f banana'],
-    [{ "deep"=>{ "cc"=>{ "code"=>"bar","bar"=>"foo" },"ss"=>{ "code"=>"bar" } } },{ "deep"=>{ "cc"=>{ "code"=>"[FILTERED]","bar"=>"foo" },"ss"=>{ "code"=>"bar" } } },%w'deep.cc.code'],
-    [{ "baz"=>[{ "foo"=>"baz" }, "1"] }, { "baz"=>[{ "foo"=>"[FILTERED]" }, "1"] }, [/foo/]]]
+    [{ "foo" => "bar" }, { "foo" => "bar" }, %w'food'],
+    [{ "foo" => "bar" }, { "foo" => "[FILTERED]" }, %w'foo'],
+    [{ "foo" => "bar", "bar" => "foo" }, { "foo" => "[FILTERED]", "bar" => "foo" }, %w'foo baz'],
+    [{ "foo" => "bar", "baz" => "foo" }, { "foo" => "[FILTERED]", "baz" => "[FILTERED]" }, %w'foo baz'],
+    [{ "bar" => { "foo" => "bar", "bar" => "foo" } }, { "bar" => { "foo" => "[FILTERED]", "bar" => "foo" } }, %w'fo'],
+    [{ "foo" => { "foo" => "bar", "bar" => "foo" } }, { "foo" => "[FILTERED]" }, %w'f banana'],
+    [{ "deep" => { "cc" => { "code" => "bar", "bar" => "foo" }, "ss" => { "code" => "bar" } } }, { "deep" => { "cc" => { "code" => "[FILTERED]", "bar" => "foo" }, "ss" => { "code" => "bar" } } }, %w'deep.cc.code'],
+    [{ "baz" => [{ "foo" => "baz" }, "1"] }, { "baz" => [{ "foo" => "[FILTERED]" }, "1"] }, [/foo/]]]
 
     test_hashes.each do |before_filter, after_filter, filter_words|
       parameter_filter = ActionDispatch::Http::ParameterFilter.new(filter_words)
@@ -1091,8 +1091,8 @@ class RequestParameterFilter < BaseRequestTest
       }
 
       parameter_filter = ActionDispatch::Http::ParameterFilter.new(filter_words)
-      before_filter["barg"] = { :bargain=>"gain", "blah"=>"bar", "bar"=>{ "bargain"=>{ "blah"=>"foo" } } }
-      after_filter["barg"]  = { :bargain=>"niag", "blah"=>"[FILTERED]", "bar"=>{ "bargain"=>{ "blah"=>"[FILTERED]" } } }
+      before_filter["barg"] = { :bargain => "gain", "blah" => "bar", "bar" => { "bargain" => { "blah" => "foo" } } }
+      after_filter["barg"]  = { :bargain => "niag", "blah" => "[FILTERED]", "bar" => { "bargain" => { "blah" => "[FILTERED]" } } }
 
       assert_equal after_filter, parameter_filter.filter(before_filter)
     end
@@ -1192,7 +1192,7 @@ class RequestEtag < BaseRequestTest
   test "doesn't match absent If-None-Match" do
     request = stub_request
 
-    assert_equal nil, request.if_none_match
+    assert_nil request.if_none_match
     assert_equal [], request.if_none_match_etags
 
     assert_not request.etag_matches?("foo")
diff --git a/actionpack/test/dispatch/response_test.rb b/actionpack/test/dispatch/response_test.rb
index 4e547ab7d5..7433c5ce0c 100644
--- a/actionpack/test/dispatch/response_test.rb
+++ b/actionpack/test/dispatch/response_test.rb
@@ -74,7 +74,7 @@ class ResponseTest < ActiveSupport::TestCase
     @response.body = "Hello, World!"
 
     # even though there's no explicitly set content-type,
-    assert_equal nil, @response.content_type
+    assert_nil @response.content_type
 
     # after the action reads back @response.body,
     assert_equal "Hello, World!", @response.body
@@ -110,6 +110,11 @@ class ResponseTest < ActiveSupport::TestCase
     assert_equal "application/aaron", @response.content_type
   end
 
+  def test_empty_content_type_returns_nil
+    @response.headers["Content-Type"] = ""
+    assert_nil @response.content_type
+  end
+
   test "simple output" do
     @response.body = "Hello, World!"
 
@@ -131,7 +136,7 @@ class ResponseTest < ActiveSupport::TestCase
   def test_only_set_charset_still_defaults_to_text_html
     response = ActionDispatch::Response.new
     response.charset = "utf-16"
-    _,headers,_ = response.to_a
+    _, headers, _ = response.to_a
     assert_equal "text/html; charset=utf-16", headers["Content-Type"]
   end
 
@@ -229,7 +234,7 @@ class ResponseTest < ActiveSupport::TestCase
 
   test "multiple cookies" do
     @response.set_cookie("user_name", value: "david", path: "/")
-    @response.set_cookie("login", value: "foo&bar", path: "/", expires: Time.utc(2005, 10, 10,5))
+    @response.set_cookie("login", value: "foo&bar", path: "/", expires: Time.utc(2005, 10, 10, 5))
     _status, headers, _body = @response.to_a
     assert_equal "user_name=david; path=/\nlogin=foo%26bar; path=/; expires=Mon, 10 Oct 2005 05:00:00 -0000", headers["Set-Cookie"]
     assert_equal({ "login" => "foo&bar", "user_name" => "david" }, @response.cookies)
@@ -237,7 +242,7 @@ class ResponseTest < ActiveSupport::TestCase
 
   test "delete cookies" do
     @response.set_cookie("user_name", value: "david", path: "/")
-    @response.set_cookie("login", value: "foo&bar", path: "/", expires: Time.utc(2005, 10, 10,5))
+    @response.set_cookie("login", value: "foo&bar", path: "/", expires: Time.utc(2005, 10, 10, 5))
     @response.delete_cookie("login")
     assert_equal({ "user_name" => "david", "login" => nil }, @response.cookies)
   end
diff --git a/actionpack/test/dispatch/routing/ipv6_redirect_test.rb b/actionpack/test/dispatch/routing/ipv6_redirect_test.rb
index 4987ed84e4..179aee9ba7 100644
--- a/actionpack/test/dispatch/routing/ipv6_redirect_test.rb
+++ b/actionpack/test/dispatch/routing/ipv6_redirect_test.rb
@@ -7,7 +7,7 @@ class IPv6IntegrationTest < ActionDispatch::IntegrationTest
   class ::BadRouteRequestController < ActionController::Base
     include Routes.url_helpers
     def index
-      render text: foo_path
+      render plain: foo_path
     end
 
     def foo
diff --git a/actionpack/test/dispatch/routing_test.rb b/actionpack/test/dispatch/routing_test.rb
index c01065932a..474d053af6 100644
--- a/actionpack/test/dispatch/routing_test.rb
+++ b/actionpack/test/dispatch/routing_test.rb
@@ -1933,7 +1933,7 @@ class TestRoutingMapper < ActionDispatch::IntegrationTest
           post :preview, on: :new
         end
 
-        resource  :admin, path_names: { new: "novo" }, path: "administrador" do
+        resource :admin, path_names: { new: "novo" }, path: "administrador" do
           post :preview, on: :new
         end
 
@@ -3736,7 +3736,7 @@ private
     https!(old_https)
   end
 
-  def verify_redirect(url, status=301)
+  def verify_redirect(url, status = 301)
     assert_equal status, @response.status
     assert_equal url, @response.headers["Location"]
     assert_equal expected_redirect_body(url), @response.body
@@ -4163,7 +4163,7 @@ class TestRedirectInterpolation < ActionDispatch::IntegrationTest
   end
 
 private
-  def verify_redirect(url, status=301)
+  def verify_redirect(url, status = 301)
     assert_equal status, @response.status
     assert_equal url, @response.headers["Location"]
     assert_equal expected_redirect_body(url), @response.body
@@ -4189,7 +4189,7 @@ class TestConstraintsAccessingParameters < ActionDispatch::IntegrationTest
 
   test "parameters are reset between constraint checks" do
     get "/bar"
-    assert_equal nil, @request.params[:foo]
+    assert_nil @request.params[:foo]
     assert_equal "bar", @request.params[:bar]
   end
 end
@@ -4696,15 +4696,15 @@ class TestUrlGenerationErrors < ActionDispatch::IntegrationTest
   end
 
   test "url helpers raise message with mixed parameters when generation fails" do
-    url, missing = { action: "show", controller: "products", id: nil, "id"=>"url-tested" }, [:id]
+    url, missing = { action: "show", controller: "products", id: nil, "id" => "url-tested" }, [:id]
     message = "No route matches #{url.inspect}, possible unmatched constraints: #{missing.inspect}"
 
     # Optimized url helper
-    error = assert_raises(ActionController::UrlGenerationError) { product_path(nil, "id"=>"url-tested") }
+    error = assert_raises(ActionController::UrlGenerationError) { product_path(nil, "id" => "url-tested") }
     assert_equal message, error.message
 
     # Non-optimized url helper
-    error = assert_raises(ActionController::UrlGenerationError, message) { product_path(id: nil, "id"=>"url-tested") }
+    error = assert_raises(ActionController::UrlGenerationError, message) { product_path(id: nil, "id" => "url-tested") }
     assert_equal message, error.message
   end
 end
diff --git a/actionpack/test/dispatch/session/cache_store_test.rb b/actionpack/test/dispatch/session/cache_store_test.rb
index a60629a7ee..859059063f 100644
--- a/actionpack/test/dispatch/session/cache_store_test.rb
+++ b/actionpack/test/dispatch/session/cache_store_test.rb
@@ -142,20 +142,20 @@ class CacheStoreTest < ActionDispatch::IntegrationTest
 
       get "/get_session_value"
       assert_response :success
-      assert_equal nil, headers["Set-Cookie"], "should not resend the cookie again if session_id cookie is already exists"
+      assert_nil headers["Set-Cookie"], "should not resend the cookie again if session_id cookie is already exists"
     end
   end
 
   def test_prevents_session_fixation
     with_test_route_set do
-      assert_equal nil, @cache.read("_session_id:0xhax")
+      assert_nil @cache.read("_session_id:0xhax")
 
       cookies["_session_id"] = "0xhax"
       get "/set_session_value"
 
       assert_response :success
       assert_not_equal "0xhax", cookies["_session_id"]
-      assert_equal nil, @cache.read("_session_id:0xhax")
+      assert_nil @cache.read("_session_id:0xhax")
       assert_equal({ "foo" => "bar" }, @cache.read("_session_id:#{cookies['_session_id']}"))
     end
   end
diff --git a/actionpack/test/dispatch/session/cookie_store_test.rb b/actionpack/test/dispatch/session/cookie_store_test.rb
index 013d289c6d..2a1053be16 100644
--- a/actionpack/test/dispatch/session/cookie_store_test.rb
+++ b/actionpack/test/dispatch/session/cookie_store_test.rb
@@ -108,7 +108,7 @@ class CookieStoreTest < ActionDispatch::IntegrationTest
     with_test_route_set(secure: true) do
       get "/set_session_value"
       assert_response :success
-      assert_equal nil, headers["Set-Cookie"]
+      assert_nil headers["Set-Cookie"]
     end
   end
 
@@ -169,7 +169,7 @@ class CookieStoreTest < ActionDispatch::IntegrationTest
     with_test_route_set do
       get "/no_session_access"
       assert_response :success
-      assert_equal nil, headers["Set-Cookie"]
+      assert_nil headers["Set-Cookie"]
     end
   end
 
@@ -179,7 +179,7 @@ class CookieStoreTest < ActionDispatch::IntegrationTest
         "fef868465920f415f2c0652d6910d3af288a0367"
       get "/no_session_access"
       assert_response :success
-      assert_equal nil, headers["Set-Cookie"]
+      assert_nil headers["Set-Cookie"]
     end
   end
 
diff --git a/actionpack/test/dispatch/session/mem_cache_store_test.rb b/actionpack/test/dispatch/session/mem_cache_store_test.rb
index c2d0719b4e..121e9ebef7 100644
--- a/actionpack/test/dispatch/session/mem_cache_store_test.rb
+++ b/actionpack/test/dispatch/session/mem_cache_store_test.rb
@@ -157,7 +157,7 @@ class MemCacheStoreTest < ActionDispatch::IntegrationTest
 
         get "/get_session_value"
         assert_response :success
-        assert_equal nil, headers["Set-Cookie"], "should not resend the cookie again if session_id cookie is already exists"
+        assert_nil headers["Set-Cookie"], "should not resend the cookie again if session_id cookie is already exists"
       end
     rescue Dalli::RingError => ex
       skip ex.message, ex.backtrace
diff --git a/actionpack/test/dispatch/static_test.rb b/actionpack/test/dispatch/static_test.rb
index aca70e180c..d8bc96e3e0 100644
--- a/actionpack/test/dispatch/static_test.rb
+++ b/actionpack/test/dispatch/static_test.rb
@@ -143,16 +143,16 @@ module StaticTests
     assert_equal "Accept-Encoding",        response.headers["Vary"]
     assert_equal "gzip",                   response.headers["Content-Encoding"]
 
-    response  = get(file_name, "HTTP_ACCEPT_ENCODING" => "Gzip")
-    assert_gzip  file_name, response
+    response = get(file_name, "HTTP_ACCEPT_ENCODING" => "Gzip")
+    assert_gzip file_name, response
 
-    response  = get(file_name, "HTTP_ACCEPT_ENCODING" => "GZIP")
-    assert_gzip  file_name, response
+    response = get(file_name, "HTTP_ACCEPT_ENCODING" => "GZIP")
+    assert_gzip file_name, response
 
-    response  = get(file_name, "HTTP_ACCEPT_ENCODING" => "compress;q=0.5, gzip;q=1.0")
-    assert_gzip  file_name, response
+    response = get(file_name, "HTTP_ACCEPT_ENCODING" => "compress;q=0.5, gzip;q=1.0")
+    assert_gzip file_name, response
 
-    response  = get(file_name, "HTTP_ACCEPT_ENCODING" => "")
+    response = get(file_name, "HTTP_ACCEPT_ENCODING" => "")
     assert_not_equal "gzip", response.headers["Content-Encoding"]
   end
 
@@ -166,7 +166,7 @@ module StaticTests
   def test_serves_gzip_with_propper_content_type_fallback
     file_name = "/gzip/foo.zoo"
     response  = get(file_name, "HTTP_ACCEPT_ENCODING" => "gzip")
-    assert_gzip  file_name, response
+    assert_gzip file_name, response
 
     default_response = get(file_name) # no gzip
     assert_equal default_response.headers["Content-Type"], response.headers["Content-Type"]
@@ -177,9 +177,9 @@ module StaticTests
     last_modified = File.mtime(File.join(@root, "#{file_name}.gz"))
     response = get(file_name, "HTTP_ACCEPT_ENCODING" => "gzip", "HTTP_IF_MODIFIED_SINCE" => last_modified.httpdate)
     assert_equal 304, response.status
-    assert_equal nil, response.headers["Content-Type"]
-    assert_equal nil, response.headers["Content-Encoding"]
-    assert_equal nil, response.headers["Vary"]
+    assert_nil response.headers["Content-Type"]
+    assert_nil response.headers["Content-Encoding"]
+    assert_nil response.headers["Vary"]
   end
 
   def test_serves_files_with_headers
@@ -204,7 +204,7 @@ module StaticTests
   end
 
   # Windows doesn't allow \ / : * ? " < > | in filenames
-  unless RbConfig::CONFIG["host_os"] =~ /mswin|mingw/
+  unless Gem.win_platform?
     def test_serves_static_file_with_colon
       with_static_file "/foo/foo:bar.html" do |file|
         assert_html file, get("/foo/foo%3Abar.html")
@@ -269,14 +269,14 @@ class StaticTest < ActiveSupport::TestCase
     filename = "shared.html.erb"
     assert File.exist?(File.join(@root, "..", filename))
     env = {
-      "REQUEST_METHOD"=>"GET",
-      "REQUEST_PATH"=>"/..%2F#{filename}",
-      "PATH_INFO"=>"/..%2F#{filename}",
-      "REQUEST_URI"=>"/..%2F#{filename}",
-      "HTTP_VERSION"=>"HTTP/1.1",
-      "SERVER_NAME"=>"localhost",
-      "SERVER_PORT"=>"8080",
-      "QUERY_STRING"=>""
+      "REQUEST_METHOD" => "GET",
+      "REQUEST_PATH" => "/..%2F#{filename}",
+      "PATH_INFO" => "/..%2F#{filename}",
+      "REQUEST_URI" => "/..%2F#{filename}",
+      "HTTP_VERSION" => "HTTP/1.1",
+      "SERVER_NAME" => "localhost",
+      "SERVER_PORT" => "8080",
+      "QUERY_STRING" => ""
     }
     assert_equal(DummyApp.call(nil), @app.call(env))
   end
diff --git a/actionpack/test/dispatch/test_request_test.rb b/actionpack/test/dispatch/test_request_test.rb
index b479af781d..85a6df4975 100644
--- a/actionpack/test/dispatch/test_request_test.rb
+++ b/actionpack/test/dispatch/test_request_test.rb
@@ -30,7 +30,7 @@ class TestRequestTest < ActiveSupport::TestCase
     req = ActionDispatch::TestRequest.create({})
 
     assert_equal({}, req.cookies)
-    assert_equal nil, req.env["HTTP_COOKIE"]
+    assert_nil req.env["HTTP_COOKIE"]
 
     req.cookie_jar["user_name"] = "david"
     assert_cookies({ "user_name" => "david" }, req.cookie_jar)
diff --git a/actionpack/test/dispatch/uploaded_file_test.rb b/actionpack/test/dispatch/uploaded_file_test.rb
index 60d0246a68..51680216e4 100644
--- a/actionpack/test/dispatch/uploaded_file_test.rb
+++ b/actionpack/test/dispatch/uploaded_file_test.rb
@@ -58,25 +58,25 @@ module ActionDispatch
     end
 
     def test_delegates_close_to_tempfile
-      tf = Class.new { def close(unlink_now=false); "thunderhorse" end }
+      tf = Class.new { def close(unlink_now = false); "thunderhorse" end }
       uf = Http::UploadedFile.new(tempfile: tf.new)
       assert_equal "thunderhorse", uf.close
     end
 
     def test_close_accepts_parameter
-      tf = Class.new { def close(unlink_now=false); "thunderhorse: #{unlink_now}" end }
+      tf = Class.new { def close(unlink_now = false); "thunderhorse: #{unlink_now}" end }
       uf = Http::UploadedFile.new(tempfile: tf.new)
       assert_equal "thunderhorse: true", uf.close(true)
     end
 
     def test_delegates_read_to_tempfile
-      tf = Class.new { def read(length=nil, buffer=nil); "thunderhorse" end }
+      tf = Class.new { def read(length = nil, buffer = nil); "thunderhorse" end }
       uf = Http::UploadedFile.new(tempfile: tf.new)
       assert_equal "thunderhorse", uf.read
     end
 
     def test_delegates_read_to_tempfile_with_params
-      tf = Class.new { def read(length=nil, buffer=nil); [length, buffer] end }
+      tf = Class.new { def read(length = nil, buffer = nil); [length, buffer] end }
       uf = Http::UploadedFile.new(tempfile: tf.new)
       assert_equal %w{ thunder horse }, uf.read(*%w{ thunder horse })
     end
diff --git a/actionpack/test/fixtures/multipart/mona_lisa.jpg b/actionpack/test/fixtures/multipart/mona_lisa.jpg
deleted file mode 100644
index 5cf3bef3d0..0000000000
--- a/actionpack/test/fixtures/multipart/mona_lisa.jpg
+++ /dev/null
diff --git a/actionpack/test/fixtures/multipart/ruby_on_rails.jpg b/actionpack/test/fixtures/multipart/ruby_on_rails.jpg
new file mode 100644
index 0000000000..ed284ea0ba
--- /dev/null
+++ b/actionpack/test/fixtures/multipart/ruby_on_rails.jpg
diff --git a/actionpack/test/fixtures/session_autoload_test/session_autoload_test/foo.rb b/actionpack/test/fixtures/session_autoload_test/session_autoload_test/foo.rb
index cd0be6d1b5..18fa5cd923 100644
--- a/actionpack/test/fixtures/session_autoload_test/session_autoload_test/foo.rb
+++ b/actionpack/test/fixtures/session_autoload_test/session_autoload_test/foo.rb
@@ -1,6 +1,6 @@
 module SessionAutoloadTest
   class Foo
-    def initialize(bar="baz")
+    def initialize(bar = "baz")
       @bar = bar
     end
     def inspect
diff --git a/actionpack/test/journey/gtg/builder_test.rb b/actionpack/test/journey/gtg/builder_test.rb
index 2b314cdd4e..aa8427b265 100644
--- a/actionpack/test/journey/gtg/builder_test.rb
+++ b/actionpack/test/journey/gtg/builder_test.rb
@@ -5,18 +5,18 @@ module ActionDispatch
     module GTG
       class TestBuilder < ActiveSupport::TestCase
         def test_following_states_multi
-          table  = tt ["a|a"]
+          table = tt ["a|a"]
           assert_equal 1, table.move([0], "a").length
         end
 
         def test_following_states_multi_regexp
-          table  = tt [":a|b"]
+          table = tt [":a|b"]
           assert_equal 1, table.move([0], "fooo").length
           assert_equal 2, table.move([0], "b").length
         end
 
         def test_multi_path
-          table  = tt ["/:a/d", "/b/c"]
+          table = tt ["/:a/d", "/b/c"]
 
           [
             [1, "/"],
@@ -38,7 +38,7 @@ module ActionDispatch
             /articles/:id(.:format)
           }
 
-          sim     = NFA::Simulator.new table
+          sim = NFA::Simulator.new table
 
           match = sim.match "/articles/new"
           assert_equal 2, match.memos.length
@@ -52,7 +52,7 @@ module ActionDispatch
             /articles/new(.:format)
           }
 
-          sim     = NFA::Simulator.new table
+          sim = NFA::Simulator.new table
 
           match = sim.match "/articles/new"
           assert_equal 2, match.memos.length
diff --git a/actionpack/test/journey/gtg/transition_table_test.rb b/actionpack/test/journey/gtg/transition_table_test.rb
index 4c8b5032eb..c7315c0338 100644
--- a/actionpack/test/journey/gtg/transition_table_test.rb
+++ b/actionpack/test/journey/gtg/transition_table_test.rb
@@ -92,7 +92,7 @@ module ActionDispatch
 
         private
           def asts(paths)
-            parser  = Journey::Parser.new
+            parser = Journey::Parser.new
             paths.map { |x|
               ast = parser.parse x
               ast.each { |n| n.memo = ast }
diff --git a/actionpack/test/journey/nfa/simulator_test.rb b/actionpack/test/journey/nfa/simulator_test.rb
index 183c892a53..38f99398cb 100644
--- a/actionpack/test/journey/nfa/simulator_test.rb
+++ b/actionpack/test/journey/nfa/simulator_test.rb
@@ -80,7 +80,7 @@ module ActionDispatch
 
           ast = Nodes::Or.new routes
 
-          nfa   = Journey::NFA::Builder.new ast
+          nfa = Journey::NFA::Builder.new ast
           sim = Simulator.new nfa.transition_table
           md = sim.match "/articles"
           assert_equal [asts.first], md.memos
diff --git a/actionpack/test/journey/nfa/transition_table_test.rb b/actionpack/test/journey/nfa/transition_table_test.rb
index f3cf36a064..0bc6bc1cf8 100644
--- a/actionpack/test/journey/nfa/transition_table_test.rb
+++ b/actionpack/test/journey/nfa/transition_table_test.rb
@@ -53,10 +53,10 @@ module ActionDispatch
         end
 
         def test_alphabet
-          table  = tt "a|:a"
+          table = tt "a|:a"
           assert_equal [/[^\.\/\?]+/, "a"], table.alphabet
 
-          table  = tt "a|a"
+          table = tt "a|a"
           assert_equal ["a"], table.alphabet
         end
 
diff --git a/actionpack/test/journey/route_test.rb b/actionpack/test/journey/route_test.rb
index b6414fd101..8fd73970b8 100644
--- a/actionpack/test/journey/route_test.rb
+++ b/actionpack/test/journey/route_test.rb
@@ -26,7 +26,7 @@ module ActionDispatch
       end
 
       def test_path_requirements_override_defaults
-        path    = Path::Pattern.build(":name", { name: /love/ }, "/", true)
+        path = Path::Pattern.build(":name", { name: /love/ }, "/", true)
         defaults  = { name: "tender" }
         route     = Route.build("name", nil, path, {}, [], defaults)
         assert_equal(/love/, route.requirements[:name])
@@ -96,7 +96,7 @@ module ActionDispatch
         path = Path::Pattern.from_string "/:controller(/:action(/:id))(.:format)"
         generic = Route.build "name", nil, path, constraints, [], {}
 
-        knowledge = { id: 20, controller: "pages", action: "show" }
+        knowledge = { "id" => true, "controller" => true, "action" => true }
 
         routes = [specific, generic]
 
diff --git a/actionpack/test/journey/router_test.rb b/actionpack/test/journey/router_test.rb
index 7b5916eb72..f223a125a3 100644
--- a/actionpack/test/journey/router_test.rb
+++ b/actionpack/test/journey/router_test.rb
@@ -6,8 +6,8 @@ module ActionDispatch
       attr_reader :mapper, :routes, :route_set, :router
 
       def setup
-        @app       = Routing::RouteSet::Dispatcher.new({})
-        @route_set  = ActionDispatch::Routing::RouteSet.new
+        @app = Routing::RouteSet::Dispatcher.new({})
+        @route_set = ActionDispatch::Routing::RouteSet.new
         @routes = @route_set.router.routes
         @router = @route_set.router
         @formatter = @route_set.formatter
@@ -116,7 +116,7 @@ module ActionDispatch
       end
 
       def test_clear_trailing_slash_from_script_name_on_root_unanchored_routes
-        app    = lambda { |env| [200, {}, ["success!"]] }
+        app = lambda { |env| [200, {}, ["success!"]] }
         get "/weblog", to: app
 
         env  = rack_env("SCRIPT_NAME" => "", "PATH_INFO" => "/weblog")
@@ -233,7 +233,7 @@ module ActionDispatch
           nil,
           Hash[params],
           {},
-          lambda { |k,v| parameterized << [k,v]; v })
+          lambda { |k, v| parameterized << [k, v]; v })
 
         assert_equal params.map(&:to_s).sort, parameterized.map(&:to_s).sort
       end
@@ -289,15 +289,15 @@ module ActionDispatch
           relative_url_root: nil
         }
         redirection_parameters = {
-          "action"=>"show",
+          "action" => "show",
         }
         missing_key = "name"
-        missing_parameters ={
+        missing_parameters = {
           missing_key => "task_1"
         }
         request_parameters = primarty_parameters.merge(redirection_parameters).merge(missing_parameters)
 
-        message = "No route matches #{Hash[request_parameters.sort_by { |k,v|k.to_s }].inspect}, missing required keys: #{[missing_key.to_sym].inspect}"
+        message = "No route matches #{Hash[request_parameters.sort_by { |k, v|k.to_s }].inspect}, missing required keys: #{[missing_key.to_sym].inspect}"
 
         error = assert_raises(ActionController::UrlGenerationError) do
           @formatter.generate(
@@ -338,7 +338,7 @@ module ActionDispatch
           route = @routes.first
 
           env = rails_env "PATH_INFO" => request_path
-          called   = false
+          called = false
 
           router.recognize(env) do |r, params|
             assert_equal route, r
@@ -358,7 +358,7 @@ module ActionDispatch
           get "/:segment/*splat", to: "foo#bar"
 
           env = rails_env "PATH_INFO" => request_path
-          called   = false
+          called = false
           route = @routes.first
 
           router.recognize(env) do |r, params|
@@ -395,7 +395,7 @@ module ActionDispatch
         get "/books(/:action(.:format))", controller: "books"
         route = @routes.first
 
-        env    = rails_env "PATH_INFO" => "/books/list.rss"
+        env = rails_env "PATH_INFO" => "/books/list.rss"
         expected = { controller: "books", action: "list", format: "rss" }
         called = false
         router.recognize(env) do |r, params|
@@ -427,7 +427,7 @@ module ActionDispatch
         get "/books(/:action(.:format))", to: "foo#bar"
 
         env = rails_env "PATH_INFO" => "/books/list.rss",
-                        "REQUEST_METHOD"    => "HEAD"
+                        "REQUEST_METHOD" => "HEAD"
 
         called = false
         router.recognize(env) do |r, params|
diff --git a/actionpack/test/journey/routes_test.rb b/actionpack/test/journey/routes_test.rb
index ca735ea022..d8db5ffad1 100644
--- a/actionpack/test/journey/routes_test.rb
+++ b/actionpack/test/journey/routes_test.rb
@@ -6,7 +6,7 @@ module ActionDispatch
       attr_reader :routes, :mapper
 
       def setup
-        @route_set  = ActionDispatch::Routing::RouteSet.new
+        @route_set = ActionDispatch::Routing::RouteSet.new
         @routes = @route_set.router.routes
         @router = @route_set.router
         @mapper = ActionDispatch::Routing::Mapper.new @route_set
diff --git a/actionpack/test/lib/controller/fake_models.rb b/actionpack/test/lib/controller/fake_models.rb
index ce9522d12a..046b4167bb 100644
--- a/actionpack/test/lib/controller/fake_models.rb
+++ b/actionpack/test/lib/controller/fake_models.rb
@@ -6,7 +6,7 @@ class Customer < Struct.new(:name, :id)
 
   undef_method :to_json
 
-  def to_xml(options={})
+  def to_xml(options = {})
     if options[:builder]
       options[:builder].name name
     else
@@ -14,7 +14,7 @@ class Customer < Struct.new(:name, :id)
     end
   end
 
-  def to_js(options={})
+  def to_js(options = {})
     "name: #{name.inspect}"
   end
   alias :to_text :to_js