132 files changed, 554 insertions, 319 deletions

diff --git a/railties/lib/rails/application.rb b/railties/lib/rails/application.rb
index ade8cb6a48..a200a1005c 100644
--- a/railties/lib/rails/application.rb
+++ b/railties/lib/rails/application.rb
@@ -174,8 +174,9 @@ module Rails
       # team. Details at https://github.com/rails/rails/pull/6952#issuecomment-7661220
       @caching_key_generator ||=
         if secret_key_base
-          ActiveSupport::CachingKeyGenerator.new \
+          ActiveSupport::CachingKeyGenerator.new(
             ActiveSupport::KeyGenerator.new(secret_key_base, iterations: 1000)
+          )
         else
           ActiveSupport::LegacyKeyGenerator.new(secrets.secret_token)
         end
@@ -265,7 +266,9 @@ module Rails
           "action_dispatch.signed_cookie_digest" => config.action_dispatch.signed_cookie_digest,
           "action_dispatch.cookies_serializer" => config.action_dispatch.cookies_serializer,
           "action_dispatch.cookies_digest" => config.action_dispatch.cookies_digest,
-          "action_dispatch.cookies_rotations" => config.action_dispatch.cookies_rotations
+          "action_dispatch.cookies_rotations" => config.action_dispatch.cookies_rotations,
+          "action_dispatch.content_security_policy" => config.content_security_policy,
+          "action_dispatch.content_security_policy_report_only" => config.content_security_policy_report_only
         )
       end
     end
@@ -400,8 +403,9 @@ module Rails
         secrets.secret_token ||= config.secret_token
 
         if secrets.secret_token.present?
-          ActiveSupport::Deprecation.warn \
+          ActiveSupport::Deprecation.warn(
             "`secrets.secret_token` is deprecated in favor of `secret_key_base` and will be removed in Rails 6.0."
+          )
         end
 
         secrets
@@ -424,19 +428,53 @@ module Rails
       if Rails.env.test? || Rails.env.development?
         Digest::MD5.hexdigest self.class.name
       else
-        validate_secret_key_base \
+        validate_secret_key_base(
           ENV["SECRET_KEY_BASE"] || credentials.secret_key_base || secrets.secret_key_base
+        )
       end
     end
 
-    # Decrypts the credentials hash as kept in `config/credentials.yml.enc`. This file is encrypted with
-    # the Rails master key, which is either taken from ENV["RAILS_MASTER_KEY"] or from loading
-    # `config/master.key`.
+    # Decrypts the credentials hash as kept in +config/credentials.yml.enc+. This file is encrypted with
+    # the Rails master key, which is either taken from <tt>ENV["RAILS_MASTER_KEY"]</tt> or from loading
+    # +config/master.key+.
     def credentials
-      @credentials ||= ActiveSupport::EncryptedConfiguration.new \
-        config_path: Rails.root.join("config/credentials.yml.enc"),
-        key_path: Rails.root.join("config/master.key"),
-        env_key: "RAILS_MASTER_KEY"
+      @credentials ||= encrypted("config/credentials.yml.enc")
+    end
+
+    # Shorthand to decrypt any encrypted configurations or files.
+    #
+    # For any file added with <tt>bin/rails encrypted:edit</tt> call +read+ to decrypt
+    # the file with the master key.
+    # The master key is either stored in +config/master.key+ or <tt>ENV["RAILS_MASTER_KEY"]</tt>.
+    #
+    #   Rails.application.encrypted("config/mystery_man.txt.enc").read
+    #   # => "We've met before, haven't we?"
+    #
+    # It's also possible to interpret encrypted YAML files with +config+.
+    #
+    #   Rails.application.encrypted("config/credentials.yml.enc").config
+    #   # => { next_guys_line: "I don't think so. Where was it you think we met?" }
+    #
+    # Any top-level configs are also accessible directly on the return value:
+    #
+    #   Rails.application.encrypted("config/credentials.yml.enc").next_guys_line
+    #   # => "I don't think so. Where was it you think we met?"
+    #
+    # The files or configs can also be encrypted with a custom key. To decrypt with
+    # a key in the +ENV+, use:
+    #
+    #   Rails.application.encrypted("config/special_tokens.yml.enc", env_key: "SPECIAL_TOKENS")
+    #
+    # Or to decrypt with a file, that should be version control ignored, relative to +Rails.root+:
+    #
+    #   Rails.application.encrypted("config/special_tokens.yml.enc", key_path: "config/special_tokens.key")
+    def encrypted(path, key_path: "config/master.key", env_key: "RAILS_MASTER_KEY")
+      ActiveSupport::EncryptedConfiguration.new(
+        config_path: Rails.root.join(path),
+        key_path: Rails.root.join(key_path),
+        env_key: env_key,
+        raise_if_missing_key: config.require_master_key
+      )
     end
 
     def to_app #:nodoc:
diff --git a/railties/lib/rails/application/configuration.rb b/railties/lib/rails/application/configuration.rb
index 290ec13878..6743ab2a54 100644
--- a/railties/lib/rails/application/configuration.rb
+++ b/railties/lib/rails/application/configuration.rb
@@ -16,44 +16,48 @@ module Rails
                     :ssl_options, :public_file_server,
                     :session_options, :time_zone, :reload_classes_only_on_change,
                     :beginning_of_week, :filter_redirect, :x, :enable_dependency_loading,
-                    :read_encrypted_secrets, :log_level
+                    :read_encrypted_secrets, :log_level, :content_security_policy_report_only,
+                    :require_master_key
 
       attr_reader :encoding, :api_only
 
       def initialize(*)
         super
-        self.encoding                    = Encoding::UTF_8
-        @allow_concurrency               = nil
-        @consider_all_requests_local     = false
-        @filter_parameters               = []
-        @filter_redirect                 = []
-        @helpers_paths                   = []
-        @public_file_server              = ActiveSupport::OrderedOptions.new
-        @public_file_server.enabled      = true
-        @public_file_server.index_name   = "index"
-        @force_ssl                       = false
-        @ssl_options                     = {}
-        @session_store                   = nil
-        @time_zone                       = "UTC"
-        @beginning_of_week               = :monday
-        @log_level                       = :debug
-        @generators                      = app_generators
-        @cache_store                     = [ :file_store, "#{root}/tmp/cache/" ]
-        @railties_order                  = [:all]
-        @relative_url_root               = ENV["RAILS_RELATIVE_URL_ROOT"]
-        @reload_classes_only_on_change   = true
-        @file_watcher                    = ActiveSupport::FileUpdateChecker
-        @exceptions_app                  = nil
-        @autoflush_log                   = true
-        @log_formatter                   = ActiveSupport::Logger::SimpleFormatter.new
-        @eager_load                      = nil
-        @secret_token                    = nil
-        @secret_key_base                 = nil
-        @api_only                        = false
-        @debug_exception_response_format = nil
-        @x                               = Custom.new
-        @enable_dependency_loading       = false
-        @read_encrypted_secrets          = false
+        self.encoding                        = Encoding::UTF_8
+        @allow_concurrency                   = nil
+        @consider_all_requests_local         = false
+        @filter_parameters                   = []
+        @filter_redirect                     = []
+        @helpers_paths                       = []
+        @public_file_server                  = ActiveSupport::OrderedOptions.new
+        @public_file_server.enabled          = true
+        @public_file_server.index_name       = "index"
+        @force_ssl                           = false
+        @ssl_options                         = {}
+        @session_store                       = nil
+        @time_zone                           = "UTC"
+        @beginning_of_week                   = :monday
+        @log_level                           = :debug
+        @generators                          = app_generators
+        @cache_store                         = [ :file_store, "#{root}/tmp/cache/" ]
+        @railties_order                      = [:all]
+        @relative_url_root                   = ENV["RAILS_RELATIVE_URL_ROOT"]
+        @reload_classes_only_on_change       = true
+        @file_watcher                        = ActiveSupport::FileUpdateChecker
+        @exceptions_app                      = nil
+        @autoflush_log                       = true
+        @log_formatter                       = ActiveSupport::Logger::SimpleFormatter.new
+        @eager_load                          = nil
+        @secret_token                        = nil
+        @secret_key_base                     = nil
+        @api_only                            = false
+        @debug_exception_response_format     = nil
+        @x                                   = Custom.new
+        @enable_dependency_loading           = false
+        @read_encrypted_secrets              = false
+        @content_security_policy             = nil
+        @content_security_policy_report_only = false
+        @require_master_key                  = false
       end
 
       def load_defaults(target_version)
@@ -71,7 +75,6 @@ module Rails
           end
 
           self.ssl_options = { hsts: { subdomains: true } }
-
         when "5.1"
           load_defaults "5.0"
 
@@ -82,7 +85,6 @@ module Rails
           if respond_to?(:action_view)
             action_view.form_with_generates_remote_forms = true
           end
-
         when "5.2"
           load_defaults "5.1"
 
@@ -100,12 +102,19 @@ module Rails
 
           if respond_to?(:active_support)
             active_support.use_authenticated_message_encryption = true
+            active_support.use_sha1_digests = true
           end
 
           if respond_to?(:action_controller)
             action_controller.default_protect_from_forgery = true
           end
 
+          if respond_to?(:action_view)
+            action_view.form_with_generates_ids = true
+          end
+        when "6.0"
+          load_defaults "5.2"
+
         else
           raise "Unknown version #{target_version.to_s.inspect}"
         end
@@ -228,6 +237,10 @@ module Rails
         SourceAnnotationExtractor::Annotation
       end
 
+      def content_security_policy(&block)
+        @content_security_policy ||= ActionDispatch::ContentSecurityPolicy.new(&block)
+      end
+
       class Custom #:nodoc:
         def initialize
           @configurations = Hash.new
diff --git a/railties/lib/rails/application/default_middleware_stack.rb b/railties/lib/rails/application/default_middleware_stack.rb
index ea2273c1f2..73c7defe7f 100644
--- a/railties/lib/rails/application/default_middleware_stack.rb
+++ b/railties/lib/rails/application/default_middleware_stack.rb
@@ -63,9 +63,14 @@ module Rails
             middleware.use ::ActionDispatch::Flash
           end
 
+          unless config.api_only
+            middleware.use ::ActionDispatch::ContentSecurityPolicy::Middleware
+          end
+
           middleware.use ::Rack::Head
           middleware.use ::Rack::ConditionalGet
           middleware.use ::Rack::ETag, "no-cache"
+          middleware.use ::Rack::TempfileReaper
         end
       end
 
diff --git a/railties/lib/rails/application/finisher.rb b/railties/lib/rails/application/finisher.rb
index 3d938be951..c4b188aeee 100644
--- a/railties/lib/rails/application/finisher.rb
+++ b/railties/lib/rails/application/finisher.rb
@@ -58,7 +58,7 @@ module Rails
       end
 
       # This needs to happen before eager load so it happens
-      # in exactly the same point regardless of config.cache_classes
+      # in exactly the same point regardless of config.eager_load
       initializer :run_prepare_callbacks do |app|
         app.reloader.prepare!
       end
diff --git a/railties/lib/rails/command/helpers/editor.rb b/railties/lib/rails/command/helpers/editor.rb
new file mode 100644
index 0000000000..6191d97672
--- /dev/null
+++ b/railties/lib/rails/command/helpers/editor.rb
@@ -0,0 +1,35 @@
+# frozen_string_literal: true
+
+require "active_support/encrypted_file"
+
+module Rails
+  module Command
+    module Helpers
+      module Editor
+        private
+          def ensure_editor_available(command:)
+            if ENV["EDITOR"].to_s.empty?
+              say "No $EDITOR to open file in. Assign one like this:"
+              say ""
+              say %(EDITOR="mate --wait" #{command})
+              say ""
+              say "For editors that fork and exit immediately, it's important to pass a wait flag,"
+              say "otherwise the credentials will be saved immediately with no chance to edit."
+
+              false
+            else
+              true
+            end
+          end
+
+          def catch_editing_exceptions
+            yield
+          rescue Interrupt
+            say "Aborted changing file: nothing saved."
+          rescue ActiveSupport::EncryptedFile::MissingKeyError => error
+            say error.message
+          end
+      end
+    end
+  end
+end
diff --git a/railties/lib/rails/commands/credentials/credentials_command.rb b/railties/lib/rails/commands/credentials/credentials_command.rb
index 1ef7c1f343..fa54c0362a 100644
--- a/railties/lib/rails/commands/credentials/credentials_command.rb
+++ b/railties/lib/rails/commands/credentials/credentials_command.rb
@@ -1,10 +1,13 @@
 # frozen_string_literal: true
 
 require "active_support"
+require "rails/command/helpers/editor"
 
 module Rails
   module Command
     class CredentialsCommand < Rails::Command::Base # :nodoc:
+      include Helpers::Editor
+
       no_commands do
         def help
           say "Usage:\n  #{self.class.banner}"
@@ -16,43 +19,27 @@ module Rails
       def edit
         require_application_and_environment!
 
-        ensure_editor_available || (return)
-        ensure_master_key_has_been_added
+        ensure_editor_available(command: "bin/rails credentials:edit") || (return)
+        ensure_master_key_has_been_added if Rails.application.credentials.key.nil?
         ensure_credentials_have_been_added
 
-        change_credentials_in_system_editor
+        catch_editing_exceptions do
+          change_credentials_in_system_editor
+        end
 
         say "New credentials encrypted and saved."
-      rescue Interrupt
-        say "Aborted changing credentials: nothing saved."
-      rescue ActiveSupport::EncryptedFile::MissingKeyError => error
-        say error.message
       end
 
       def show
         require_application_and_environment!
-        say Rails.application.credentials.read.presence ||
-          "No credentials have been added yet. Use bin/rails credentials:edit to change that."
+
+        say Rails.application.credentials.read.presence || missing_credentials_message
       end
 
       private
-        def ensure_editor_available
-          if ENV["EDITOR"].to_s.empty?
-            say "No $EDITOR to open credentials in. Assign one like this:"
-            say ""
-            say %(EDITOR="mate --wait" bin/rails credentials:edit)
-            say ""
-            say "For editors that fork and exit immediately, it's important to pass a wait flag,"
-            say "otherwise the credentials will be saved immediately with no chance to edit."
-
-            false
-          else
-            true
-          end
-        end
-
         def ensure_master_key_has_been_added
           master_key_generator.add_master_key_file
+          master_key_generator.ignore_master_key_file
         end
 
         def ensure_credentials_have_been_added
@@ -79,6 +66,14 @@ module Rails
 
           Rails::Generators::CredentialsGenerator.new
         end
+
+        def missing_credentials_message
+          if Rails.application.credentials.key.nil?
+            "Missing master key to decrypt credentials. See bin/rails credentials:help"
+          else
+            "No credentials have been added yet. Use bin/rails credentials:edit to change that."
+          end
+        end
     end
   end
 end
diff --git a/railties/lib/rails/commands/encrypted/encrypted_command.rb b/railties/lib/rails/commands/encrypted/encrypted_command.rb
new file mode 100644
index 0000000000..3bc8f76ce4
--- /dev/null
+++ b/railties/lib/rails/commands/encrypted/encrypted_command.rb
@@ -0,0 +1,86 @@
+# frozen_string_literal: true
+
+require "pathname"
+require "active_support"
+require "rails/command/helpers/editor"
+
+module Rails
+  module Command
+    class EncryptedCommand < Rails::Command::Base # :nodoc:
+      include Helpers::Editor
+
+      class_option :key, aliases: "-k", type: :string,
+        default: "config/master.key", desc: "The Rails.root relative path to the encryption key"
+
+      no_commands do
+        def help
+          say "Usage:\n  #{self.class.banner}"
+          say ""
+        end
+      end
+
+      def edit(file_path)
+        require_application_and_environment!
+        encrypted = Rails.application.encrypted(file_path, key_path: options[:key])
+
+        ensure_editor_available(command: "bin/rails encrypted:edit") || (return)
+        ensure_encryption_key_has_been_added(options[:key]) if encrypted.key.nil?
+        ensure_encrypted_file_has_been_added(file_path, options[:key])
+
+        catch_editing_exceptions do
+          change_encrypted_file_in_system_editor(file_path, options[:key])
+        end
+
+        say "File encrypted and saved."
+      rescue ActiveSupport::MessageEncryptor::InvalidMessage
+        say "Couldn't decrypt #{file_path}. Perhaps you passed the wrong key?"
+      end
+
+      def show(file_path)
+        require_application_and_environment!
+        encrypted = Rails.application.encrypted(file_path, key_path: options[:key])
+
+        say encrypted.read.presence || missing_encrypted_message(key: encrypted.key, key_path: options[:key], file_path: file_path)
+      end
+
+      private
+        def ensure_encryption_key_has_been_added(key_path)
+          encryption_key_file_generator.add_key_file(key_path)
+          encryption_key_file_generator.ignore_key_file(key_path)
+        end
+
+        def ensure_encrypted_file_has_been_added(file_path, key_path)
+          encrypted_file_generator.add_encrypted_file_silently(file_path, key_path)
+        end
+
+        def change_encrypted_file_in_system_editor(file_path, key_path)
+          Rails.application.encrypted(file_path, key_path: key_path).change do |tmp_path|
+            system("#{ENV["EDITOR"]} #{tmp_path}")
+          end
+        end
+
+
+        def encryption_key_file_generator
+          require "rails/generators"
+          require "rails/generators/rails/encryption_key_file/encryption_key_file_generator"
+
+          Rails::Generators::EncryptionKeyFileGenerator.new
+        end
+
+        def encrypted_file_generator
+          require "rails/generators"
+          require "rails/generators/rails/encrypted_file/encrypted_file_generator"
+
+          Rails::Generators::EncryptedFileGenerator.new
+        end
+
+        def missing_encrypted_message(key:, key_path:, file_path:)
+          if key.nil?
+            "Missing '#{key_path}' to decrypt data. See bin/rails encrypted:help"
+          else
+            "File '#{file_path}' does not exist. Use bin/rails encrypted:edit #{file_path} to change that."
+          end
+        end
+    end
+  end
+end
diff --git a/railties/lib/rails/commands/secrets/secrets_command.rb b/railties/lib/rails/commands/secrets/secrets_command.rb
index c91139e33b..a36ccf314c 100644
--- a/railties/lib/rails/commands/secrets/secrets_command.rb
+++ b/railties/lib/rails/commands/secrets/secrets_command.rb
@@ -15,7 +15,7 @@ module Rails
       end
 
       def setup
-        generator.start
+        deprecate_in_favor_of_credentials_and_exit
       end
 
       def edit
@@ -42,11 +42,10 @@ module Rails
       rescue Rails::Secrets::MissingKeyError => error
         say error.message
       rescue Errno::ENOENT => error
-        raise unless error.message =~ /secrets\.yml\.enc/
-
-        Rails::Secrets.read_template_for_editing do |tmp_path|
-          system("#{ENV["EDITOR"]} #{tmp_path}")
-          generator.skip_secrets_file { setup }
+        if error.message =~ /secrets\.yml\.enc/
+          deprecate_in_favor_of_credentials_and_exit
+        else
+          raise
         end
       end
 
@@ -55,11 +54,11 @@ module Rails
       end
 
       private
-        def generator
-          require "rails/generators"
-          require "rails/generators/rails/encrypted_secrets/encrypted_secrets_generator"
+        def deprecate_in_favor_of_credentials_and_exit
+          say "Encrypted secrets is deprecated in favor of credentials. Run:"
+          say "bin/rails credentials:help"
 
-          Rails::Generators::EncryptedSecretsGenerator
+          exit 1
         end
     end
   end
diff --git a/railties/lib/rails/commands/server/server_command.rb b/railties/lib/rails/commands/server/server_command.rb
index 703ec59087..e546fe3e4b 100644
--- a/railties/lib/rails/commands/server/server_command.rb
+++ b/railties/lib/rails/commands/server/server_command.rb
@@ -27,7 +27,7 @@ module Rails
         app = super
         if app.is_a?(Class)
           ActiveSupport::Deprecation.warn(<<-MSG.squish)
-            Use `Rails::Application` subclass to start the server is deprecated and will be removed in Rails 6.0.
+            Using `Rails::Application` subclass to start the server is deprecated and will be removed in Rails 6.0.
             Please change `run #{app}` to `run Rails.application` in config.ru.
           MSG
         end
diff --git a/railties/lib/rails/gem_version.rb b/railties/lib/rails/gem_version.rb
index 92b5e0392a..54bfbdd516 100644
--- a/railties/lib/rails/gem_version.rb
+++ b/railties/lib/rails/gem_version.rb
@@ -7,8 +7,8 @@ module Rails
   end
 
   module VERSION
-    MAJOR = 5
-    MINOR = 2
+    MAJOR = 6
+    MINOR = 0
     TINY  = 0
     PRE   = "alpha"
 
diff --git a/railties/lib/rails/generators.rb b/railties/lib/rails/generators.rb
index 5592e8d78e..6a7175c02b 100644
--- a/railties/lib/rails/generators.rb
+++ b/railties/lib/rails/generators.rb
@@ -218,6 +218,9 @@ module Rails
         rails.delete("app")
         rails.delete("plugin")
         rails.delete("encrypted_secrets")
+        rails.delete("encrypted_file")
+        rails.delete("encryption_key_file")
+        rails.delete("master_key")
         rails.delete("credentials")
 
         hidden_namespaces.each { |n| groups.delete(n.to_s) }
@@ -274,8 +277,9 @@ module Rails
         else
           options     = sorted_groups.flat_map(&:last)
           suggestions = options.sort_by { |suggested| levenshtein_distance(namespace.to_s, suggested) }.first(3)
+          suggestions.map! { |s| "'#{s}'" }
           msg =  "Could not find generator '#{namespace}'. ".dup
-          msg << "Maybe you meant #{ suggestions.map { |s| "'#{s}'" }.to_sentence(last_word_connector: " or ", locale: :en) }\n"
+          msg << "Maybe you meant #{ suggestions[0...-1].join(', ')} or #{suggestions[-1]}\n"
           msg << "Run `rails generate --help` for more options."
           puts msg
         end
diff --git a/railties/lib/rails/generators/app_base.rb b/railties/lib/rails/generators/app_base.rb
index bdeddff645..863a914912 100644
--- a/railties/lib/rails/generators/app_base.rb
+++ b/railties/lib/rails/generators/app_base.rb
@@ -84,6 +84,9 @@ module Rails
         class_option :skip_system_test,    type: :boolean, default: false,
                                            desc: "Skip system test files"
 
+        class_option :skip_bootsnap,       type: :boolean, default: false,
+                                           desc: "Skip bootsnap gem"
+
         class_option :dev,                 type: :boolean, default: false,
                                            desc: "Setup the #{name} with Gemfile pointing to your Rails checkout"
 
@@ -192,7 +195,7 @@ module Rails
       def webserver_gemfile_entry # :doc:
         return [] if options[:skip_puma]
         comment = "Use Puma as the app server"
-        GemfileEntry.new("puma", "~> 3.7", comment)
+        GemfileEntry.new("puma", "~> 3.11", comment)
       end
 
       def include_all_railties? # :doc:
@@ -266,17 +269,14 @@ module Rails
       end
 
       def rails_gemfile_entry
-        dev_edge_common = [
-          GemfileEntry.github("arel", "rails/arel"),
-        ]
         if options.dev?
           [
             GemfileEntry.path("rails", Rails::Generators::RAILS_DEV_PATH)
-          ] + dev_edge_common
+          ]
         elsif options.edge?
           [
             GemfileEntry.github("rails", "rails/rails")
-          ] + dev_edge_common
+          ]
         else
           [GemfileEntry.version("rails",
                             rails_version_specifier,
@@ -300,8 +300,8 @@ module Rails
       def gem_for_database
         # %w( mysql postgresql sqlite3 oracle frontbase ibm_db sqlserver jdbcmysql jdbcsqlite3 jdbcpostgresql )
         case options[:database]
-        when "mysql"          then ["mysql2", [">= 0.3.18", "< 0.5"]]
-        when "postgresql"     then ["pg", ["~> 0.18"]]
+        when "mysql"          then ["mysql2", ["~> 0.4.4"]]
+        when "postgresql"     then ["pg", [">= 0.18", "< 2.0"]]
         when "oracle"         then ["activerecord-oracle_enhanced-adapter", nil]
         when "frontbase"      then ["ruby-frontbase", nil]
         when "sqlserver"      then ["activerecord-sqlserver-adapter", nil]
@@ -315,11 +315,13 @@ module Rails
 
       def convert_database_option_for_jruby
         if defined?(JRUBY_VERSION)
-          case options[:database]
-          when "postgresql" then options[:database].replace "jdbcpostgresql"
-          when "mysql"      then options[:database].replace "jdbcmysql"
-          when "sqlite3"    then options[:database].replace "jdbcsqlite3"
+          opt = options.dup
+          case opt[:database]
+          when "postgresql" then opt[:database] = "jdbcpostgresql"
+          when "mysql"      then opt[:database] = "jdbcmysql"
+          when "sqlite3"    then opt[:database] = "jdbcsqlite3"
           end
+          self.options = opt.freeze
         end
       end
 
@@ -438,6 +440,10 @@ module Rails
         !options[:skip_listen] && os_supports_listen_out_of_the_box?
       end
 
+      def depend_on_bootsnap?
+        !options[:skip_bootsnap] && !options[:dev]
+      end
+
       def os_supports_listen_out_of_the_box?
         RbConfig::CONFIG["host_os"] =~ /darwin|linux/
       end
@@ -459,16 +465,6 @@ module Rails
         end
       end
 
-      def run_active_storage
-        unless skip_active_storage?
-          if bundle_install?
-            rails_command "active_storage:install", capture: options[:quiet]
-          else
-            log("Active Storage installation was skipped. Please run `bin/rails active_storage:install` to install Active Storage files.")
-          end
-        end
-      end
-
       def empty_directory_with_keep_file(destination, config = {})
         empty_directory(destination, config)
         keep_file(destination)
diff --git a/railties/lib/rails/generators/erb/controller/templates/view.html.erb b/railties/lib/rails/generators/erb/controller/templates/view.html.erb.tt
index cd54d13d83..cd54d13d83 100644
--- a/railties/lib/rails/generators/erb/controller/templates/view.html.erb
+++ b/railties/lib/rails/generators/erb/controller/templates/view.html.erb.tt
diff --git a/railties/lib/rails/generators/erb/mailer/templates/view.html.erb b/railties/lib/rails/generators/erb/mailer/templates/view.html.erb.tt
index b5045671b3..b5045671b3 100644
--- a/railties/lib/rails/generators/erb/mailer/templates/view.html.erb
+++ b/railties/lib/rails/generators/erb/mailer/templates/view.html.erb.tt
diff --git a/railties/lib/rails/generators/erb/mailer/templates/view.text.erb b/railties/lib/rails/generators/erb/mailer/templates/view.text.erb.tt
index 342285df19..342285df19 100644
--- a/railties/lib/rails/generators/erb/mailer/templates/view.text.erb
+++ b/railties/lib/rails/generators/erb/mailer/templates/view.text.erb.tt
diff --git a/railties/lib/rails/generators/erb/scaffold/templates/_form.html.erb b/railties/lib/rails/generators/erb/scaffold/templates/_form.html.erb.tt
index 0eb9d82bbb..518cb1121e 100644
--- a/railties/lib/rails/generators/erb/scaffold/templates/_form.html.erb
+++ b/railties/lib/rails/generators/erb/scaffold/templates/_form.html.erb.tt
@@ -15,15 +15,15 @@
   <div class="field">
 <% if attribute.password_digest? -%>
     <%%= form.label :password %>
-    <%%= form.password_field :password, id: :<%= field_id(:password) %> %>
+    <%%= form.password_field :password %>
   </div>
 
   <div class="field">
     <%%= form.label :password_confirmation %>
-    <%%= form.password_field :password_confirmation, id: :<%= field_id(:password_confirmation) %> %>
+    <%%= form.password_field :password_confirmation %>
 <% else -%>
     <%%= form.label :<%= attribute.column_name %> %>
-    <%%= form.<%= attribute.field_type %> :<%= attribute.column_name %>, id: :<%= field_id(attribute.column_name) %> %>
+    <%%= form.<%= attribute.field_type %> :<%= attribute.column_name %> %>
 <% end -%>
   </div>
 
diff --git a/railties/lib/rails/generators/erb/scaffold/templates/edit.html.erb b/railties/lib/rails/generators/erb/scaffold/templates/edit.html.erb.tt
index 81329473d9..81329473d9 100644
--- a/railties/lib/rails/generators/erb/scaffold/templates/edit.html.erb
+++ b/railties/lib/rails/generators/erb/scaffold/templates/edit.html.erb.tt
diff --git a/railties/lib/rails/generators/erb/scaffold/templates/index.html.erb b/railties/lib/rails/generators/erb/scaffold/templates/index.html.erb.tt
index e1ede7c713..e1ede7c713 100644
--- a/railties/lib/rails/generators/erb/scaffold/templates/index.html.erb
+++ b/railties/lib/rails/generators/erb/scaffold/templates/index.html.erb.tt
diff --git a/railties/lib/rails/generators/erb/scaffold/templates/new.html.erb b/railties/lib/rails/generators/erb/scaffold/templates/new.html.erb.tt
index 9b2b2f4875..9b2b2f4875 100644
--- a/railties/lib/rails/generators/erb/scaffold/templates/new.html.erb
+++ b/railties/lib/rails/generators/erb/scaffold/templates/new.html.erb.tt
diff --git a/railties/lib/rails/generators/erb/scaffold/templates/show.html.erb b/railties/lib/rails/generators/erb/scaffold/templates/show.html.erb.tt
index 5e634153be..5e634153be 100644
--- a/railties/lib/rails/generators/erb/scaffold/templates/show.html.erb
+++ b/railties/lib/rails/generators/erb/scaffold/templates/show.html.erb.tt
diff --git a/railties/lib/rails/generators/generated_attribute.rb b/railties/lib/rails/generators/generated_attribute.rb
index 2728459968..f7fd30a5fb 100644
--- a/railties/lib/rails/generators/generated_attribute.rb
+++ b/railties/lib/rails/generators/generated_attribute.rb
@@ -75,7 +75,7 @@ module Rails
                         when :date                 then :date_select
                         when :text                 then :text_area
                         when :boolean              then :check_box
-          else
+                        else
                           :text_field
         end
       end
@@ -91,7 +91,7 @@ module Rails
                      when :text                        then "MyText"
                      when :boolean                     then false
                      when :references, :belongs_to     then nil
-          else
+                     else
                        ""
         end
       end
diff --git a/railties/lib/rails/generators/named_base.rb b/railties/lib/rails/generators/named_base.rb
index 99165168fd..98fcc95964 100644
--- a/railties/lib/rails/generators/named_base.rb
+++ b/railties/lib/rails/generators/named_base.rb
@@ -114,10 +114,6 @@ module Rails
           "new_#{singular_route_name}_url"
         end
 
-        def field_id(attribute_name)
-          [singular_table_name, attribute_name].join("_")
-        end
-
         def singular_table_name # :doc:
           @singular_table_name ||= (pluralize_table_names? ? table_name.singularize : table_name)
         end
diff --git a/railties/lib/rails/generators/rails/app/app_generator.rb b/railties/lib/rails/generators/rails/app/app_generator.rb
index 1c32fad3ea..fd9da7803f 100644
--- a/railties/lib/rails/generators/rails/app/app_generator.rb
+++ b/railties/lib/rails/generators/rails/app/app_generator.rb
@@ -128,6 +128,7 @@ module Rails
       active_storage_config_exist    = File.exist?("config/storage.yml")
       rack_cors_config_exist         = File.exist?("config/initializers/cors.rb")
       assets_config_exist            = File.exist?("config/initializers/assets.rb")
+      csp_config_exist               = File.exist?("config/initializers/content_security_policy.rb")
 
       config
 
@@ -155,27 +156,27 @@ module Rails
         unless assets_config_exist
           remove_file "config/initializers/assets.rb"
         end
+
+        unless csp_config_exist
+          remove_file "config/initializers/content_security_policy.rb"
+        end
       end
     end
 
     def master_key
-      return if options[:pretend]
+      return if options[:pretend] || options[:dummy_app]
 
       require "rails/generators/rails/master_key/master_key_generator"
-
-      after_bundle do
-        Rails::Generators::MasterKeyGenerator.new([], quiet: options[:quiet]).add_master_key_file
-      end
+      master_key_generator = Rails::Generators::MasterKeyGenerator.new([], quiet: options[:quiet])
+      master_key_generator.add_master_key_file_silently
+      master_key_generator.ignore_master_key_file_silently
     end
 
     def credentials
-      return if options[:pretend]
+      return if options[:pretend] || options[:dummy_app]
 
       require "rails/generators/rails/credentials/credentials_generator"
-
-      after_bundle do
-        Rails::Generators::CredentialsGenerator.new([], quiet: options[:quiet]).add_credentials_file_silently
-      end
+      Rails::Generators::CredentialsGenerator.new([], quiet: options[:quiet]).add_credentials_file_silently
     end
 
     def database_yml
@@ -347,6 +348,14 @@ module Rails
         build(:public_directory)
       end
 
+      def create_tmp_files
+        build(:tmp)
+      end
+
+      def create_vendor_files
+        build(:vendor)
+      end
+
       def create_test_files
         build(:test) unless options[:skip_test]
       end
@@ -359,14 +368,6 @@ module Rails
         build(:storage) unless skip_active_storage?
       end
 
-      def create_tmp_files
-        build(:tmp)
-      end
-
-      def create_vendor_files
-        build(:vendor)
-      end
-
       def delete_app_assets_if_api_option
         if options[:api]
           remove_dir "app/assets"
@@ -436,6 +437,7 @@ module Rails
       def delete_non_api_initializers_if_api_option
         if options[:api]
           remove_file "config/initializers/cookies_serializer.rb"
+          remove_file "config/initializers/content_security_policy.rb"
         end
       end
 
@@ -461,7 +463,6 @@ module Rails
 
       public_task :apply_rails_template, :run_bundle
       public_task :run_webpack, :generate_spring_binstubs
-      public_task :run_active_storage
 
       def run_after_bundle_callbacks
         @after_bundle_callbacks.each(&:call)
diff --git a/railties/lib/rails/generators/rails/app/templates/Gemfile b/railties/lib/rails/generators/rails/app/templates/Gemfile.tt
index 61026f5182..23bb89f4ce 100644
--- a/railties/lib/rails/generators/rails/app/templates/Gemfile
+++ b/railties/lib/rails/generators/rails/app/templates/Gemfile.tt
@@ -29,9 +29,11 @@ ruby <%= "'#{RUBY_VERSION}'" -%>
 # Use Capistrano for deployment
 # gem 'capistrano-rails', group: :development
 
+<% if depend_on_bootsnap? -%>
 # Reduces boot times through caching; required in config/boot.rb
 gem 'bootsnap', '>= 1.1.0', require: false
 
+<%- end -%>
 <%- if options.api? -%>
 # Use Rack CORS for handling Cross-Origin Resource Sharing (CORS), making cross-origin AJAX possible
 # gem 'rack-cors'
@@ -41,13 +43,6 @@ gem 'bootsnap', '>= 1.1.0', require: false
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
   gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
-  <%- if depends_on_system_test? -%>
-  # Adds support for Capybara system testing and selenium driver
-  gem 'capybara', '~> 2.15'
-  gem 'selenium-webdriver'
-  # Easy installation and use of chromedriver to run system tests with Chrome
-  gem 'chromedriver-helper'
-  <%- end -%>
 end
 
 group :development do
@@ -70,6 +65,16 @@ group :development do
 <% end -%>
 <% end -%>
 end
+
+<%- if depends_on_system_test? -%>
+group :test do
+  # Adds support for Capybara system testing and selenium driver
+  gem 'capybara', '~> 2.15'
+  gem 'selenium-webdriver'
+  # Easy installation and use of chromedriver to run system tests with Chrome
+  gem 'chromedriver-helper'
+end
+<%- end -%>
 <% end -%>
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
diff --git a/railties/lib/rails/generators/rails/app/templates/README.md b/railties/lib/rails/generators/rails/app/templates/README.md.tt
index 7db80e4ca1..7db80e4ca1 100644
--- a/railties/lib/rails/generators/rails/app/templates/README.md
+++ b/railties/lib/rails/generators/rails/app/templates/README.md.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/Rakefile b/railties/lib/rails/generators/rails/app/templates/Rakefile.tt
index e85f913914..e85f913914 100644
--- a/railties/lib/rails/generators/rails/app/templates/Rakefile
+++ b/railties/lib/rails/generators/rails/app/templates/Rakefile.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/app/assets/javascripts/cable.js b/railties/lib/rails/generators/rails/app/templates/app/assets/javascripts/cable.js.tt
index 739aa5f022..739aa5f022 100644
--- a/railties/lib/rails/generators/rails/app/templates/app/assets/javascripts/cable.js
+++ b/railties/lib/rails/generators/rails/app/templates/app/assets/javascripts/cable.js.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/app/assets/stylesheets/application.css b/railties/lib/rails/generators/rails/app/templates/app/assets/stylesheets/application.css.tt
index d05ea0f511..d05ea0f511 100644
--- a/railties/lib/rails/generators/rails/app/templates/app/assets/stylesheets/application.css
+++ b/railties/lib/rails/generators/rails/app/templates/app/assets/stylesheets/application.css.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/app/channels/application_cable/channel.rb b/railties/lib/rails/generators/rails/app/templates/app/channels/application_cable/channel.rb.tt
index d672697283..d672697283 100644
--- a/railties/lib/rails/generators/rails/app/templates/app/channels/application_cable/channel.rb
+++ b/railties/lib/rails/generators/rails/app/templates/app/channels/application_cable/channel.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/app/channels/application_cable/connection.rb b/railties/lib/rails/generators/rails/app/templates/app/channels/application_cable/connection.rb.tt
index 0ff5442f47..0ff5442f47 100644
--- a/railties/lib/rails/generators/rails/app/templates/app/channels/application_cable/connection.rb
+++ b/railties/lib/rails/generators/rails/app/templates/app/channels/application_cable/connection.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/app/helpers/application_helper.rb b/railties/lib/rails/generators/rails/app/templates/app/helpers/application_helper.rb.tt
index de6be7945c..de6be7945c 100644
--- a/railties/lib/rails/generators/rails/app/templates/app/helpers/application_helper.rb
+++ b/railties/lib/rails/generators/rails/app/templates/app/helpers/application_helper.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/app/jobs/application_job.rb b/railties/lib/rails/generators/rails/app/templates/app/jobs/application_job.rb.tt
index a009ace51c..a009ace51c 100644
--- a/railties/lib/rails/generators/rails/app/templates/app/jobs/application_job.rb
+++ b/railties/lib/rails/generators/rails/app/templates/app/jobs/application_job.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/app/mailers/application_mailer.rb b/railties/lib/rails/generators/rails/app/templates/app/mailers/application_mailer.rb.tt
index 286b2239d1..286b2239d1 100644
--- a/railties/lib/rails/generators/rails/app/templates/app/mailers/application_mailer.rb
+++ b/railties/lib/rails/generators/rails/app/templates/app/mailers/application_mailer.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/app/models/application_record.rb b/railties/lib/rails/generators/rails/app/templates/app/models/application_record.rb.tt
index 10a4cba84d..10a4cba84d 100644
--- a/railties/lib/rails/generators/rails/app/templates/app/models/application_record.rb
+++ b/railties/lib/rails/generators/rails/app/templates/app/models/application_record.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/bin/bundle b/railties/lib/rails/generators/rails/app/templates/bin/bundle.tt
index a84f0afe47..a84f0afe47 100644
--- a/railties/lib/rails/generators/rails/app/templates/bin/bundle
+++ b/railties/lib/rails/generators/rails/app/templates/bin/bundle.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/bin/rails b/railties/lib/rails/generators/rails/app/templates/bin/rails.tt
index 513a2e0183..513a2e0183 100644
--- a/railties/lib/rails/generators/rails/app/templates/bin/rails
+++ b/railties/lib/rails/generators/rails/app/templates/bin/rails.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/bin/rake b/railties/lib/rails/generators/rails/app/templates/bin/rake.tt
index d14fc8395b..d14fc8395b 100644
--- a/railties/lib/rails/generators/rails/app/templates/bin/rake
+++ b/railties/lib/rails/generators/rails/app/templates/bin/rake.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/bin/yarn b/railties/lib/rails/generators/rails/app/templates/bin/yarn.tt
index b4e4d95286..90ddcc520e 100644
--- a/railties/lib/rails/generators/rails/app/templates/bin/yarn
+++ b/railties/lib/rails/generators/rails/app/templates/bin/yarn.tt
@@ -1,7 +1,7 @@
 APP_ROOT = File.expand_path('..', __dir__)
 Dir.chdir(APP_ROOT) do
   begin
-    exec "yarnpkg #{ARGV.join(' ')}"
+    exec "yarnpkg", *ARGV
   rescue Errno::ENOENT
     $stderr.puts "Yarn executable was not detected in the system."
     $stderr.puts "Download Yarn at https://yarnpkg.com/en/docs/install"
diff --git a/railties/lib/rails/generators/rails/app/templates/config.ru b/railties/lib/rails/generators/rails/app/templates/config.ru.tt
index f7ba0b527b..f7ba0b527b 100644
--- a/railties/lib/rails/generators/rails/app/templates/config.ru
+++ b/railties/lib/rails/generators/rails/app/templates/config.ru.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/application.rb b/railties/lib/rails/generators/rails/app/templates/config/application.rb.tt
index 9e03e86771..d1a09f9c3c 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/application.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/application.rb.tt
@@ -27,8 +27,9 @@ module <%= app_const_base %>
     config.load_defaults <%= Rails::VERSION::STRING.to_f %>
 
     # Settings in config/environments/* take precedence over those specified here.
-    # Application configuration should go into files in config/initializers
-    # -- all .rb files in that directory are automatically loaded.
+    # Application configuration can go into files in config/initializers
+    # -- all .rb files in that directory are automatically loaded after loading
+    # the framework and any gems in your application.
 <%- if options.api? -%>
 
     # Only loads a smaller set of middleware suitable for API only apps.
diff --git a/railties/lib/rails/generators/rails/app/templates/config/boot.rb b/railties/lib/rails/generators/rails/app/templates/config/boot.rb.tt
index b9e460cef3..42d46b8175 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/boot.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/boot.rb.tt
@@ -1,4 +1,6 @@
 ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
 
 require 'bundler/setup' # Set up gems listed in the Gemfile.
+<% if depend_on_bootsnap? -%>
 require 'bootsnap/setup' # Speed up boot time by caching expensive operations.
+<%- end -%>
diff --git a/railties/lib/rails/generators/rails/app/templates/config/cable.yml b/railties/lib/rails/generators/rails/app/templates/config/cable.yml.tt
index 8e53156c71..8e53156c71 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/cable.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/cable.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/frontbase.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/frontbase.yml.tt
index 917b52e535..917b52e535 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/databases/frontbase.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/frontbase.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/ibm_db.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/ibm_db.yml.tt
index d40117a27f..d40117a27f 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/databases/ibm_db.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/ibm_db.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/jdbc.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/jdbc.yml.tt
index 563be77710..563be77710 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/databases/jdbc.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/jdbc.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcmysql.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcmysql.yml.tt
index 2a67bdca25..2a67bdca25 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcmysql.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcmysql.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcpostgresql.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcpostgresql.yml.tt
index 70df04079d..70df04079d 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcpostgresql.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcpostgresql.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcsqlite3.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcsqlite3.yml.tt
index 371415e6a8..371415e6a8 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcsqlite3.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/jdbcsqlite3.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/mysql.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/mysql.yml.tt
index 04afaa0596..04afaa0596 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/databases/mysql.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/mysql.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/oracle.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/oracle.yml.tt
index 6da0601b24..6da0601b24 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/databases/oracle.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/oracle.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/postgresql.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/postgresql.yml.tt
index 145cfb7f74..145cfb7f74 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/databases/postgresql.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/postgresql.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/sqlite3.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/sqlite3.yml.tt
index 9510568124..9510568124 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/databases/sqlite3.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/sqlite3.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/databases/sqlserver.yml b/railties/lib/rails/generators/rails/app/templates/config/databases/sqlserver.yml.tt
index 049de65f22..049de65f22 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/databases/sqlserver.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/databases/sqlserver.yml.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/environment.rb b/railties/lib/rails/generators/rails/app/templates/config/environment.rb.tt
index 426333bb46..426333bb46 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/environment.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/environment.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt
index b383228dc0..a87649b50f 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config/environments/development.rb.tt
@@ -14,7 +14,7 @@ Rails.application.configure do
 
   # Enable/disable caching. By default caching is disabled.
   # Run rails dev:cache to toggle caching.
-  if Rails.root.join('tmp/caching-dev.txt').exist?
+  if Rails.root.join('tmp', 'caching-dev.txt').exist?
     config.action_controller.perform_caching = true
 
     config.cache_store = :memory_store
@@ -46,6 +46,9 @@ Rails.application.configure do
   # Raise an error on page load if there are pending migrations.
   config.active_record.migration_error = :page_load
 
+  # Highlight code that triggered database queries in logs.
+  config.active_record.verbose_query_logs = true
+
   <%- end -%>
   <%- unless options.skip_sprockets? -%>
   # Debug mode disables concatenation and preprocessing of assets.
diff --git a/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt
index 4c0f36db98..926326b5bb 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config/environments/production.rb.tt
@@ -34,8 +34,6 @@ Rails.application.configure do
   # Do not fallback to assets pipeline if a precompiled asset is missed.
   config.assets.compile = false
 
-  # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb
-
   <%- end -%>
   # Enable serving of images, stylesheets, and JavaScripts from an asset server.
   # config.action_controller.asset_host = 'http://assets.example.com'
diff --git a/railties/lib/rails/generators/rails/app/templates/config/initializers/application_controller_renderer.rb b/railties/lib/rails/generators/rails/app/templates/config/initializers/application_controller_renderer.rb.tt
index 89d2efab2b..89d2efab2b 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/initializers/application_controller_renderer.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/initializers/application_controller_renderer.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/initializers/backtrace_silencers.rb b/railties/lib/rails/generators/rails/app/templates/config/initializers/backtrace_silencers.rb.tt
index 59385cdf37..59385cdf37 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/initializers/backtrace_silencers.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/initializers/backtrace_silencers.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/initializers/content_security_policy.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/initializers/content_security_policy.rb.tt
new file mode 100644
index 0000000000..edde7f42b8
--- /dev/null
+++ b/railties/lib/rails/generators/rails/app/templates/config/initializers/content_security_policy.rb.tt
@@ -0,0 +1,22 @@
+# Be sure to restart your server when you modify this file.
+
+# Define an application-wide content security policy
+# For further information see the following documentation
+# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy
+
+# Rails.application.config.content_security_policy do |policy|
+#   policy.default_src :self, :https
+#   policy.font_src    :self, :https, :data
+#   policy.img_src     :self, :https, :data
+#   policy.object_src  :none
+#   policy.script_src  :self, :https
+#   policy.style_src   :self, :https, :unsafe_inline
+
+#   # Specify URI for violation reports
+#   # policy.report_uri "/csp-violation-report-endpoint"
+# end
+
+# Report CSP violations to a specified URI
+# For further information see the following documentation:
+# https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy-Report-Only
+# Rails.application.config.content_security_policy_report_only = true
diff --git a/railties/lib/rails/generators/rails/app/templates/config/initializers/cookies_serializer.rb b/railties/lib/rails/generators/rails/app/templates/config/initializers/cookies_serializer.rb.tt
index 5a6a32d371..5a6a32d371 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/initializers/cookies_serializer.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/initializers/cookies_serializer.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/initializers/cors.rb b/railties/lib/rails/generators/rails/app/templates/config/initializers/cors.rb.tt
index 3b1c1b5ed1..3b1c1b5ed1 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/initializers/cors.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/initializers/cors.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/initializers/filter_parameter_logging.rb b/railties/lib/rails/generators/rails/app/templates/config/initializers/filter_parameter_logging.rb.tt
index 4a994e1e7b..4a994e1e7b 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/initializers/filter_parameter_logging.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/initializers/filter_parameter_logging.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/initializers/inflections.rb b/railties/lib/rails/generators/rails/app/templates/config/initializers/inflections.rb.tt
index ac033bf9dc..ac033bf9dc 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/initializers/inflections.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/initializers/inflections.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/initializers/mime_types.rb b/railties/lib/rails/generators/rails/app/templates/config/initializers/mime_types.rb.tt
index dc1899682b..dc1899682b 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/initializers/mime_types.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/initializers/mime_types.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/initializers/new_framework_defaults_5_2.rb.tt b/railties/lib/rails/generators/rails/app/templates/config/initializers/new_framework_defaults_5_2.rb.tt
index 25dcddb27a..b4ef455802 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/initializers/new_framework_defaults_5_2.rb.tt
+++ b/railties/lib/rails/generators/rails/app/templates/config/initializers/new_framework_defaults_5_2.rb.tt
@@ -10,7 +10,7 @@
 # This is needed for recyclable cache keys.
 # Rails.application.config.active_record.cache_versioning = true
 
-# Use AES 256 GCM authenticated encryption for encrypted cookies.
+# Use AES-256-GCM authenticated encryption for encrypted cookies.
 # Existing cookies will be converted on read then written with the new scheme.
 # Rails.application.config.action_dispatch.use_authenticated_cookie_encryption = true
 
@@ -25,3 +25,6 @@
 # Store boolean values are in sqlite3 databases as 1 and 0 instead of 't' and
 # 'f' after migrating old data.
 # Rails.application.config.active_record.sqlite3.represent_boolean_as_integer = true
+
+# Use SHA-1 instead of MD5 to generate non-sensitive digests, such as the ETag header.
+# Rails.application.config.active_support.use_sha1_digests = true
diff --git a/railties/lib/rails/generators/rails/app/templates/config/puma.rb b/railties/lib/rails/generators/rails/app/templates/config/puma.rb.tt
index 1e19380dcb..a5eccf816b 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/puma.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/puma.rb.tt
@@ -26,31 +26,9 @@ environment ENV.fetch("RAILS_ENV") { "development" }
 # Use the `preload_app!` method when specifying a `workers` number.
 # This directive tells Puma to first boot the application and load code
 # before forking the application. This takes advantage of Copy On Write
-# process behavior so workers use less memory. If you use this option
-# you need to make sure to reconnect any threads in the `on_worker_boot`
-# block.
+# process behavior so workers use less memory.
 #
 # preload_app!
 
-# If you are preloading your application and using Active Record, it's
-# recommended that you close any connections to the database before workers
-# are forked to prevent connection leakage.
-#
-# before_fork do
-#   ActiveRecord::Base.connection_pool.disconnect! if defined?(ActiveRecord)
-# end
-
-# The code in the `on_worker_boot` will be called if you are using
-# clustered mode by specifying a number of `workers`. After each worker
-# process is booted, this block will be run. If you are using the `preload_app!`
-# option, you will want to use this block to reconnect to any threads
-# or connections that may have been created at application boot, as Ruby
-# cannot share connections between processes.
-#
-# on_worker_boot do
-#   ActiveRecord::Base.establish_connection if defined?(ActiveRecord)
-# end
-#
-
 # Allow puma to be restarted by `rails restart` command.
 plugin :tmp_restart
diff --git a/railties/lib/rails/generators/rails/app/templates/config/routes.rb b/railties/lib/rails/generators/rails/app/templates/config/routes.rb.tt
index 787824f888..787824f888 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/routes.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/routes.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/spring.rb b/railties/lib/rails/generators/rails/app/templates/config/spring.rb.tt
index 9fa7863f99..9fa7863f99 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/spring.rb
+++ b/railties/lib/rails/generators/rails/app/templates/config/spring.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/config/storage.yml b/railties/lib/rails/generators/rails/app/templates/config/storage.yml.tt
index 9bada4b66d..1c0cde0b09 100644
--- a/railties/lib/rails/generators/rails/app/templates/config/storage.yml
+++ b/railties/lib/rails/generators/rails/app/templates/config/storage.yml.tt
@@ -18,7 +18,7 @@ local:
 # google:
 #   service: GCS
 #   project: your_project
-#   keyfile: <%%= Rails.root.join("path/to/gcs.keyfile") %>
+#   credentials: <%%= Rails.root.join("path/to/gcs.keyfile") %>
 #   bucket: your_own_bucket
 
 # Use rails credentials:edit to set the Azure Storage secret (as azure_storage:storage_access_key)
diff --git a/railties/lib/rails/generators/rails/app/templates/gitignore b/railties/lib/rails/generators/rails/app/templates/gitignore.tt
index 2cd8335aba..2cd8335aba 100644
--- a/railties/lib/rails/generators/rails/app/templates/gitignore
+++ b/railties/lib/rails/generators/rails/app/templates/gitignore.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/package.json b/railties/lib/rails/generators/rails/app/templates/package.json.tt
index 46db57dcbe..46db57dcbe 100644
--- a/railties/lib/rails/generators/rails/app/templates/package.json
+++ b/railties/lib/rails/generators/rails/app/templates/package.json.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/ruby-version b/railties/lib/rails/generators/rails/app/templates/ruby-version.tt
index c444f33b0f..c444f33b0f 100644
--- a/railties/lib/rails/generators/rails/app/templates/ruby-version
+++ b/railties/lib/rails/generators/rails/app/templates/ruby-version.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/test/application_system_test_case.rb b/railties/lib/rails/generators/rails/app/templates/test/application_system_test_case.rb.tt
index d19212abd5..d19212abd5 100644
--- a/railties/lib/rails/generators/rails/app/templates/test/application_system_test_case.rb
+++ b/railties/lib/rails/generators/rails/app/templates/test/application_system_test_case.rb.tt
diff --git a/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb b/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb.tt
index 6ad1f11781..52d68cc77c 100644
--- a/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb
+++ b/railties/lib/rails/generators/rails/app/templates/test/test_helper.rb.tt
@@ -1,3 +1,4 @@
+ENV['RAILS_ENV'] ||= 'test'
 require_relative '../config/environment'
 require 'rails/test_help'
 
diff --git a/railties/lib/rails/generators/rails/assets/templates/stylesheet.css b/railties/lib/rails/generators/rails/assets/templates/stylesheet.css
index 7594abf268..afad32db02 100644
--- a/railties/lib/rails/generators/rails/assets/templates/stylesheet.css
+++ b/railties/lib/rails/generators/rails/assets/templates/stylesheet.css
@@ -1,4 +1,4 @@
-/* 
+/*
   Place all the styles related to the matching controller here.
   They will automatically be included in application.css.
 */
diff --git a/railties/lib/rails/generators/rails/controller/templates/controller.rb b/railties/lib/rails/generators/rails/controller/templates/controller.rb.tt
index 633e0b3177..633e0b3177 100644
--- a/railties/lib/rails/generators/rails/controller/templates/controller.rb
+++ b/railties/lib/rails/generators/rails/controller/templates/controller.rb.tt
diff --git a/railties/lib/rails/generators/rails/credentials/credentials_generator.rb b/railties/lib/rails/generators/rails/credentials/credentials_generator.rb
index 52cb4bd8bf..0fb4d5fbd1 100644
--- a/railties/lib/rails/generators/rails/credentials/credentials_generator.rb
+++ b/railties/lib/rails/generators/rails/credentials/credentials_generator.rb
@@ -2,19 +2,17 @@
 
 require "rails/generators/base"
 require "rails/generators/rails/master_key/master_key_generator"
+require "active_support/core_ext/string/strip"
 require "active_support/encrypted_configuration"
 
 module Rails
   module Generators
-    class CredentialsGenerator < Base
-      CONFIG_PATH = "config/credentials.yml.enc"
-      KEY_PATH    = "config/master.key"
-
+    class CredentialsGenerator < Base # :nodoc:
       def add_credentials_file
-        unless File.exist?(CONFIG_PATH)
+        unless credentials.content_path.exist?
           template = credentials_template
 
-          say "Adding #{CONFIG_PATH} to store encrypted credentials."
+          say "Adding #{credentials.content_path} to store encrypted credentials."
           say ""
           say "The following content has been encrypted with the Rails master key:"
           say ""
@@ -29,17 +27,30 @@ module Rails
       end
 
       def add_credentials_file_silently(template = nil)
-        unless File.exist?(CONFIG_PATH)
-          setup = { config_path: CONFIG_PATH, key_path: KEY_PATH, env_key: "RAILS_MASTER_KEY" }
-          ActiveSupport::EncryptedConfiguration.new(setup).write(credentials_template)
+        unless credentials.content_path.exist?
+          credentials.write(credentials_template)
         end
       end
 
       private
+        def credentials
+          ActiveSupport::EncryptedConfiguration.new(
+            config_path: "config/credentials.yml.enc",
+            key_path: "config/master.key",
+            env_key: "RAILS_MASTER_KEY",
+            raise_if_missing_key: true
+          )
+        end
+
         def credentials_template
-          "# aws:\n#  access_key_id: 123\n#  secret_access_key: 345\n\n" +
-          "# Used as the base secret for all MessageVerifiers in Rails, including the one protecting cookies.\n" +
-          "secret_key_base: #{SecureRandom.hex(64)}"
+          <<-YAML.strip_heredoc
+          # aws:
+          #   access_key_id: 123
+          #   secret_access_key: 345
+
+          # Used as the base secret for all MessageVerifiers in Rails, including the one protecting cookies.
+          secret_key_base: #{SecureRandom.hex(64)}
+          YAML
         end
     end
   end
diff --git a/railties/lib/rails/generators/rails/encrypted_file/encrypted_file_generator.rb b/railties/lib/rails/generators/rails/encrypted_file/encrypted_file_generator.rb
new file mode 100644
index 0000000000..ef398f52a1
--- /dev/null
+++ b/railties/lib/rails/generators/rails/encrypted_file/encrypted_file_generator.rb
@@ -0,0 +1,28 @@
+# frozen_string_literal: true
+
+require "rails/generators/base"
+require "active_support/core_ext/string/strip"
+require "active_support/encrypted_file"
+
+module Rails
+  module Generators
+    class EncryptedFileGenerator < Base # :nodoc:
+      def add_encrypted_file_silently(file_path, key_path, template = encrypted_file_template)
+        unless File.exist?(file_path)
+          setup = { content_path: file_path, key_path: key_path, env_key: "RAILS_MASTER_KEY", raise_if_missing_key: true }
+          ActiveSupport::EncryptedFile.new(setup).write(template)
+        end
+      end
+
+      private
+        def encrypted_file_template
+          <<-YAML.strip_heredoc
+          # aws:
+          #   access_key_id: 123
+          #   secret_access_key: 345
+
+          YAML
+        end
+    end
+  end
+end
diff --git a/railties/lib/rails/generators/rails/encrypted_secrets/encrypted_secrets_generator.rb b/railties/lib/rails/generators/rails/encrypted_secrets/encrypted_secrets_generator.rb
deleted file mode 100644
index 1aa7a2622a..0000000000
--- a/railties/lib/rails/generators/rails/encrypted_secrets/encrypted_secrets_generator.rb
+++ /dev/null
@@ -1,72 +0,0 @@
-# frozen_string_literal: true
-
-require "rails/generators/base"
-require "rails/secrets"
-
-module Rails
-  module Generators
-    class EncryptedSecretsGenerator < Base
-      def add_secrets_key_file
-        unless File.exist?("config/secrets.yml.key") || File.exist?("config/secrets.yml.enc")
-          key = Rails::Secrets.generate_key
-
-          say "Adding config/secrets.yml.key to store the encryption key: #{key}"
-          say ""
-          say "Save this in a password manager your team can access."
-          say ""
-          say "If you lose the key, no one, including you, can access any encrypted secrets."
-
-          say ""
-          create_file "config/secrets.yml.key", key
-          say ""
-        end
-      end
-
-      def ignore_key_file
-        if File.exist?(".gitignore")
-          unless File.read(".gitignore").include?(key_ignore)
-            say "Ignoring config/secrets.yml.key so it won't end up in Git history:"
-            say ""
-            append_to_file ".gitignore", key_ignore
-            say ""
-          end
-        else
-          say "IMPORTANT: Don't commit config/secrets.yml.key. Add this to your ignore file:"
-          say key_ignore, :on_green
-          say ""
-        end
-      end
-
-      def add_encrypted_secrets_file
-        unless (defined?(@@skip_secrets_file) && @@skip_secrets_file) || File.exist?("config/secrets.yml.enc")
-          say "Adding config/secrets.yml.enc to store secrets that needs to be encrypted."
-          say ""
-          say "For now the file contains this but it's been encrypted with the generated key:"
-          say ""
-          say Secrets.template, :on_green
-          say ""
-
-          Secrets.write(Secrets.template)
-
-          say "You can edit encrypted secrets with `bin/rails secrets:edit`."
-          say ""
-        end
-
-        say "Add this to your config/environments/production.rb:"
-        say "config.read_encrypted_secrets = true"
-      end
-
-      def self.skip_secrets_file
-        @@skip_secrets_file = true
-        yield
-      ensure
-        @@skip_secrets_file = false
-      end
-
-      private
-        def key_ignore
-          [ "", "# Ignore encrypted secrets key file.", "config/secrets.yml.key", "" ].join("\n")
-        end
-    end
-  end
-end
diff --git a/railties/lib/rails/generators/rails/encryption_key_file/encryption_key_file_generator.rb b/railties/lib/rails/generators/rails/encryption_key_file/encryption_key_file_generator.rb
new file mode 100644
index 0000000000..90068c678d
--- /dev/null
+++ b/railties/lib/rails/generators/rails/encryption_key_file/encryption_key_file_generator.rb
@@ -0,0 +1,57 @@
+# frozen_string_literal: true
+
+require "pathname"
+require "rails/generators/base"
+require "active_support/encrypted_file"
+
+module Rails
+  module Generators
+    class EncryptionKeyFileGenerator < Base # :nodoc:
+      def add_key_file(key_path)
+        key_path = Pathname.new(key_path)
+
+        unless key_path.exist?
+          key = ActiveSupport::EncryptedFile.generate_key
+
+          log "Adding #{key_path} to store the encryption key: #{key}"
+          log ""
+          log "Save this in a password manager your team can access."
+          log ""
+          log "If you lose the key, no one, including you, can access anything encrypted with it."
+
+          log ""
+          add_key_file_silently(key_path, key)
+          log ""
+        end
+      end
+
+      def add_key_file_silently(key_path, key = nil)
+        create_file key_path, key || ActiveSupport::EncryptedFile.generate_key
+      end
+
+      def ignore_key_file(key_path, ignore: key_ignore(key_path))
+        if File.exist?(".gitignore")
+          unless File.read(".gitignore").include?(ignore)
+            log "Ignoring #{key_path} so it won't end up in Git history:"
+            log ""
+            append_to_file ".gitignore", ignore
+            log ""
+          end
+        else
+          log "IMPORTANT: Don't commit #{key_path}. Add this to your ignore file:"
+          log ignore, :on_green
+          log ""
+        end
+      end
+
+      def ignore_key_file_silently(key_path, ignore: key_ignore(key_path))
+        append_to_file ".gitignore", ignore if File.exist?(".gitignore")
+      end
+
+      private
+        def key_ignore(key_path)
+          [ "", "/#{key_path}", "" ].join("\n")
+        end
+    end
+  end
+end
diff --git a/railties/lib/rails/generators/rails/helper/templates/helper.rb b/railties/lib/rails/generators/rails/helper/templates/helper.rb.tt
index b4173151b4..b4173151b4 100644
--- a/railties/lib/rails/generators/rails/helper/templates/helper.rb
+++ b/railties/lib/rails/generators/rails/helper/templates/helper.rb.tt
diff --git a/railties/lib/rails/generators/rails/master_key/master_key_generator.rb b/railties/lib/rails/generators/rails/master_key/master_key_generator.rb
index 23dbed20ac..82968985dc 100644
--- a/railties/lib/rails/generators/rails/master_key/master_key_generator.rb
+++ b/railties/lib/rails/generators/rails/master_key/master_key_generator.rb
@@ -1,12 +1,13 @@
 # frozen_string_literal: true
 
-require "rails/generators/base"
 require "pathname"
+require "rails/generators/base"
+require "rails/generators/rails/encryption_key_file/encryption_key_file_generator"
 require "active_support/encrypted_file"
 
 module Rails
   module Generators
-    class MasterKeyGenerator < Base
+    class MasterKeyGenerator < Base # :nodoc:
       MASTER_KEY_PATH = Pathname.new("config/master.key")
 
       def add_master_key_file
@@ -20,27 +21,26 @@ module Rails
           log "If you lose the key, no one, including you, can access anything encrypted with it."
 
           log ""
-          create_file MASTER_KEY_PATH, key
+          add_master_key_file_silently(key)
           log ""
-
-          ignore_master_key_file
         end
       end
 
+      def add_master_key_file_silently(key = nil)
+        key_file_generator.add_key_file_silently(MASTER_KEY_PATH, key)
+      end
+
+      def ignore_master_key_file
+        key_file_generator.ignore_key_file(MASTER_KEY_PATH, ignore: key_ignore)
+      end
+
+      def ignore_master_key_file_silently
+        key_file_generator.ignore_key_file_silently(MASTER_KEY_PATH, ignore: key_ignore)
+      end
+
       private
-        def ignore_master_key_file
-          if File.exist?(".gitignore")
-            unless File.read(".gitignore").include?(key_ignore)
-              log "Ignoring #{MASTER_KEY_PATH} so it won't end up in Git history:"
-              log ""
-              append_to_file ".gitignore", key_ignore
-              log ""
-            end
-          else
-            log "IMPORTANT: Don't commit #{MASTER_KEY_PATH}. Add this to your ignore file:"
-            log key_ignore, :on_green
-            log ""
-          end
+        def key_file_generator
+          EncryptionKeyFileGenerator.new([], options)
         end
 
         def key_ignore
diff --git a/railties/lib/rails/generators/rails/plugin/plugin_generator.rb b/railties/lib/rails/generators/rails/plugin/plugin_generator.rb
index bc2dcf008e..a83c911806 100644
--- a/railties/lib/rails/generators/rails/plugin/plugin_generator.rb
+++ b/railties/lib/rails/generators/rails/plugin/plugin_generator.rb
@@ -98,6 +98,7 @@ task default: :test
       opts[:skip_listen] = true
       opts[:skip_git] = true
       opts[:skip_turbolinks] = true
+      opts[:dummy_app] = true
 
       invoke Rails::Generators::AppGenerator,
         [ File.expand_path(dummy_path, destination_root) ], opts
@@ -166,7 +167,7 @@ task default: :test
 
       gemfile_in_app_path = File.join(rails_app_path, "Gemfile")
       if File.exist? gemfile_in_app_path
-        entry = "gem '#{name}', path: '#{relative_path}'"
+        entry = "\ngem '#{name}', path: '#{relative_path}'"
         append_file gemfile_in_app_path, entry
       end
     end
@@ -262,6 +263,10 @@ task default: :test
       public_task :apply_rails_template
 
       def run_after_bundle_callbacks
+        unless @after_bundle_callbacks.empty?
+          ActiveSupport::Deprecation.warn("`after_bundle` is deprecated and will be removed in the next version of Rails. ")
+        end
+
         @after_bundle_callbacks.each do |callback|
           callback.call
         end
diff --git a/railties/lib/rails/generators/rails/plugin/templates/%name%.gemspec b/railties/lib/rails/generators/rails/plugin/templates/%name%.gemspec.tt
index 9a8c4bf098..9a8c4bf098 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/%name%.gemspec
+++ b/railties/lib/rails/generators/rails/plugin/templates/%name%.gemspec.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/Gemfile b/railties/lib/rails/generators/rails/plugin/templates/Gemfile.tt
index 290259b4db..290259b4db 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/Gemfile
+++ b/railties/lib/rails/generators/rails/plugin/templates/Gemfile.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/MIT-LICENSE b/railties/lib/rails/generators/rails/plugin/templates/MIT-LICENSE.tt
index ff2fb3ba4e..ff2fb3ba4e 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/MIT-LICENSE
+++ b/railties/lib/rails/generators/rails/plugin/templates/MIT-LICENSE.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/README.md b/railties/lib/rails/generators/rails/plugin/templates/README.md.tt
index 1632409bea..1632409bea 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/README.md
+++ b/railties/lib/rails/generators/rails/plugin/templates/README.md.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/Rakefile b/railties/lib/rails/generators/rails/plugin/templates/Rakefile.tt
index f3efe21cf1..f3efe21cf1 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/Rakefile
+++ b/railties/lib/rails/generators/rails/plugin/templates/Rakefile.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/config/routes.rb b/railties/lib/rails/generators/rails/plugin/templates/config/routes.rb.tt
index 154452bfe5..154452bfe5 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/config/routes.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/config/routes.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/gitignore b/railties/lib/rails/generators/rails/plugin/templates/gitignore.tt
index 7a68da5c4b..7a68da5c4b 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/gitignore
+++ b/railties/lib/rails/generators/rails/plugin/templates/gitignore.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%.rb b/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%.rb.tt
index 3285055eb7..3285055eb7 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/engine.rb b/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/engine.rb.tt
index 8938770fc4..8938770fc4 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/engine.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/engine.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/railtie.rb b/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/railtie.rb.tt
index 7bdf4ee5fb..7bdf4ee5fb 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/railtie.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/railtie.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/version.rb b/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/version.rb.tt
index b08f4ef9ae..b08f4ef9ae 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/version.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/lib/%namespaced_name%/version.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/lib/tasks/%namespaced_name%_tasks.rake b/railties/lib/rails/generators/rails/plugin/templates/lib/tasks/%namespaced_name%_tasks.rake.tt
index 88a2c4120f..88a2c4120f 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/lib/tasks/%namespaced_name%_tasks.rake
+++ b/railties/lib/rails/generators/rails/plugin/templates/lib/tasks/%namespaced_name%_tasks.rake.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/rails/application.rb b/railties/lib/rails/generators/rails/plugin/templates/rails/application.rb.tt
index 06ffe2f1ed..06ffe2f1ed 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/rails/application.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/application.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/rails/boot.rb b/railties/lib/rails/generators/rails/plugin/templates/rails/boot.rb.tt
index c9aef85d40..c9aef85d40 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/rails/boot.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/boot.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/rails/dummy_manifest.js b/railties/lib/rails/generators/rails/plugin/templates/rails/dummy_manifest.js.tt
index 03937cf8ff..03937cf8ff 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/rails/dummy_manifest.js
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/dummy_manifest.js.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/rails/engine_manifest.js b/railties/lib/rails/generators/rails/plugin/templates/rails/engine_manifest.js.tt
index 2f23844f5e..2f23844f5e 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/rails/engine_manifest.js
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/engine_manifest.js.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/rails/javascripts.js b/railties/lib/rails/generators/rails/plugin/templates/rails/javascripts.js.tt
index f3d80c87f5..f3d80c87f5 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/rails/javascripts.js
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/javascripts.js.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/rails/routes.rb b/railties/lib/rails/generators/rails/plugin/templates/rails/routes.rb.tt
index 694510edc0..694510edc0 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/rails/routes.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/rails/routes.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/test/%namespaced_name%_test.rb b/railties/lib/rails/generators/rails/plugin/templates/test/%namespaced_name%_test.rb.tt
index 1ee05d7871..1ee05d7871 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/test/%namespaced_name%_test.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/test/%namespaced_name%_test.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/test/application_system_test_case.rb b/railties/lib/rails/generators/rails/plugin/templates/test/application_system_test_case.rb.tt
index d19212abd5..d19212abd5 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/test/application_system_test_case.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/test/application_system_test_case.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/test/integration/navigation_test.rb b/railties/lib/rails/generators/rails/plugin/templates/test/integration/navigation_test.rb.tt
index 29e59d8407..29e59d8407 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/test/integration/navigation_test.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/test/integration/navigation_test.rb.tt
diff --git a/railties/lib/rails/generators/rails/plugin/templates/test/test_helper.rb b/railties/lib/rails/generators/rails/plugin/templates/test/test_helper.rb.tt
index 7fa9973931..755d19ef5d 100644
--- a/railties/lib/rails/generators/rails/plugin/templates/test/test_helper.rb
+++ b/railties/lib/rails/generators/rails/plugin/templates/test/test_helper.rb.tt
@@ -1,3 +1,6 @@
+# Configure Rails Environment
+ENV["RAILS_ENV"] = "test"
+
 require_relative "<%= File.join('..', options[:dummy_path], 'config/environment') -%>"
 <% unless options[:skip_active_record] -%>
 ActiveRecord::Migrator.migrations_paths = [File.expand_path("../<%= options[:dummy_path] -%>/db/migrate", __dir__)]
diff --git a/railties/lib/rails/generators/rails/scaffold_controller/templates/api_controller.rb b/railties/lib/rails/generators/rails/scaffold_controller/templates/api_controller.rb.tt
index 400afec6dc..400afec6dc 100644
--- a/railties/lib/rails/generators/rails/scaffold_controller/templates/api_controller.rb
+++ b/railties/lib/rails/generators/rails/scaffold_controller/templates/api_controller.rb.tt
diff --git a/railties/lib/rails/generators/rails/scaffold_controller/templates/controller.rb b/railties/lib/rails/generators/rails/scaffold_controller/templates/controller.rb.tt
index 05f1c2b2d3..05f1c2b2d3 100644
--- a/railties/lib/rails/generators/rails/scaffold_controller/templates/controller.rb
+++ b/railties/lib/rails/generators/rails/scaffold_controller/templates/controller.rb.tt
diff --git a/railties/lib/rails/generators/rails/task/templates/task.rb b/railties/lib/rails/generators/rails/task/templates/task.rb.tt
index 1e3ed5f158..1e3ed5f158 100644
--- a/railties/lib/rails/generators/rails/task/templates/task.rb
+++ b/railties/lib/rails/generators/rails/task/templates/task.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/controller/templates/functional_test.rb b/railties/lib/rails/generators/test_unit/controller/templates/functional_test.rb.tt
index ff41fef9e9..ff41fef9e9 100644
--- a/railties/lib/rails/generators/test_unit/controller/templates/functional_test.rb
+++ b/railties/lib/rails/generators/test_unit/controller/templates/functional_test.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/generator/templates/generator_test.rb b/railties/lib/rails/generators/test_unit/generator/templates/generator_test.rb.tt
index a7f1fc4fba..a7f1fc4fba 100644
--- a/railties/lib/rails/generators/test_unit/generator/templates/generator_test.rb
+++ b/railties/lib/rails/generators/test_unit/generator/templates/generator_test.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/integration/templates/integration_test.rb b/railties/lib/rails/generators/test_unit/integration/templates/integration_test.rb.tt
index 118e0f1271..118e0f1271 100644
--- a/railties/lib/rails/generators/test_unit/integration/templates/integration_test.rb
+++ b/railties/lib/rails/generators/test_unit/integration/templates/integration_test.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/job/job_generator.rb b/railties/lib/rails/generators/test_unit/job/job_generator.rb
index 9225af4e0c..a99ce914c0 100644
--- a/railties/lib/rails/generators/test_unit/job/job_generator.rb
+++ b/railties/lib/rails/generators/test_unit/job/job_generator.rb
@@ -8,7 +8,7 @@ module TestUnit # :nodoc:
       check_class_collision suffix: "JobTest"
 
       def create_test_file
-        template "unit_test.rb.erb", File.join("test/jobs", class_path, "#{file_name}_job_test.rb")
+        template "unit_test.rb", File.join("test/jobs", class_path, "#{file_name}_job_test.rb")
       end
     end
   end
diff --git a/railties/lib/rails/generators/test_unit/job/templates/unit_test.rb.erb b/railties/lib/rails/generators/test_unit/job/templates/unit_test.rb.tt
index f5351d0ec6..f5351d0ec6 100644
--- a/railties/lib/rails/generators/test_unit/job/templates/unit_test.rb.erb
+++ b/railties/lib/rails/generators/test_unit/job/templates/unit_test.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/mailer/templates/functional_test.rb b/railties/lib/rails/generators/test_unit/mailer/templates/functional_test.rb.tt
index a2f2d30de5..a2f2d30de5 100644
--- a/railties/lib/rails/generators/test_unit/mailer/templates/functional_test.rb
+++ b/railties/lib/rails/generators/test_unit/mailer/templates/functional_test.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/mailer/templates/preview.rb b/railties/lib/rails/generators/test_unit/mailer/templates/preview.rb.tt
index b063cbc47b..b063cbc47b 100644
--- a/railties/lib/rails/generators/test_unit/mailer/templates/preview.rb
+++ b/railties/lib/rails/generators/test_unit/mailer/templates/preview.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/model/templates/fixtures.yml b/railties/lib/rails/generators/test_unit/model/templates/fixtures.yml.tt
index 0681780c97..0681780c97 100644
--- a/railties/lib/rails/generators/test_unit/model/templates/fixtures.yml
+++ b/railties/lib/rails/generators/test_unit/model/templates/fixtures.yml.tt
diff --git a/railties/lib/rails/generators/test_unit/model/templates/unit_test.rb b/railties/lib/rails/generators/test_unit/model/templates/unit_test.rb.tt
index c9bc7d5b90..c9bc7d5b90 100644
--- a/railties/lib/rails/generators/test_unit/model/templates/unit_test.rb
+++ b/railties/lib/rails/generators/test_unit/model/templates/unit_test.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/scaffold/scaffold_generator.rb b/railties/lib/rails/generators/test_unit/scaffold/scaffold_generator.rb
index b6c13b41ae..e2e8b18eab 100644
--- a/railties/lib/rails/generators/test_unit/scaffold/scaffold_generator.rb
+++ b/railties/lib/rails/generators/test_unit/scaffold/scaffold_generator.rb
@@ -23,7 +23,7 @@ module TestUnit # :nodoc:
         template template_file,
                  File.join("test/controllers", controller_class_path, "#{controller_file_name}_controller_test.rb")
 
-        unless options.api? || options[:system_tests].nil?
+        if !options.api? && options[:system_tests]
           template "system_test.rb", File.join("test/system", class_path, "#{file_name.pluralize}_test.rb")
         end
       end
diff --git a/railties/lib/rails/generators/test_unit/scaffold/templates/api_functional_test.rb b/railties/lib/rails/generators/test_unit/scaffold/templates/api_functional_test.rb.tt
index f21861d8e6..f21861d8e6 100644
--- a/railties/lib/rails/generators/test_unit/scaffold/templates/api_functional_test.rb
+++ b/railties/lib/rails/generators/test_unit/scaffold/templates/api_functional_test.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/scaffold/templates/functional_test.rb b/railties/lib/rails/generators/test_unit/scaffold/templates/functional_test.rb.tt
index 195d60be20..195d60be20 100644
--- a/railties/lib/rails/generators/test_unit/scaffold/templates/functional_test.rb
+++ b/railties/lib/rails/generators/test_unit/scaffold/templates/functional_test.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/scaffold/templates/system_test.rb b/railties/lib/rails/generators/test_unit/scaffold/templates/system_test.rb.tt
index f83f5a5c62..f83f5a5c62 100644
--- a/railties/lib/rails/generators/test_unit/scaffold/templates/system_test.rb
+++ b/railties/lib/rails/generators/test_unit/scaffold/templates/system_test.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/system/templates/application_system_test_case.rb b/railties/lib/rails/generators/test_unit/system/templates/application_system_test_case.rb.tt
index d19212abd5..d19212abd5 100644
--- a/railties/lib/rails/generators/test_unit/system/templates/application_system_test_case.rb
+++ b/railties/lib/rails/generators/test_unit/system/templates/application_system_test_case.rb.tt
diff --git a/railties/lib/rails/generators/test_unit/system/templates/system_test.rb b/railties/lib/rails/generators/test_unit/system/templates/system_test.rb.tt
index b5ce2ba5c8..b5ce2ba5c8 100644
--- a/railties/lib/rails/generators/test_unit/system/templates/system_test.rb
+++ b/railties/lib/rails/generators/test_unit/system/templates/system_test.rb.tt
diff --git a/railties/lib/rails/info.rb b/railties/lib/rails/info.rb
index d8f361f524..d5c9973c6b 100644
--- a/railties/lib/rails/info.rb
+++ b/railties/lib/rails/info.rb
@@ -99,7 +99,7 @@ module Rails
     end
 
     property "Database schema version" do
-      ActiveRecord::Migrator.current_version rescue nil
+      ActiveRecord::Base.connection.migration_context.current_version rescue nil
     end
   end
 end
diff --git a/railties/lib/rails/mailers_controller.rb b/railties/lib/rails/mailers_controller.rb
index 66636e5d6b..0b0e802358 100644
--- a/railties/lib/rails/mailers_controller.rb
+++ b/railties/lib/rails/mailers_controller.rb
@@ -6,9 +6,9 @@ class Rails::MailersController < Rails::ApplicationController # :nodoc:
   prepend_view_path ActionDispatch::DebugExceptions::RESCUES_TEMPLATE_PATH
 
   before_action :require_local!, unless: :show_previews?
-  before_action :find_preview, only: :preview
+  before_action :find_preview, :set_locale, only: :preview
 
-  helper_method :part_query
+  helper_method :part_query, :locale_query
 
   def index
     @previews = ActionMailer::Preview.all
@@ -84,4 +84,12 @@ class Rails::MailersController < Rails::ApplicationController # :nodoc:
     def part_query(mime_type)
       request.query_parameters.merge(part: mime_type).to_query
     end
+
+    def locale_query(locale)
+      request.query_parameters.merge(locale: locale).to_query
+    end
+
+    def set_locale
+      I18n.locale = params[:locale] || I18n.default_locale
+    end
 end
diff --git a/railties/lib/rails/railtie/configuration.rb b/railties/lib/rails/railtie/configuration.rb
index 48853129bc..70274b948c 100644
--- a/railties/lib/rails/railtie/configuration.rb
+++ b/railties/lib/rails/railtie/configuration.rb
@@ -55,7 +55,7 @@ module Rails
         ActiveSupport.on_load(:before_configuration, yield: true, &block)
       end
 
-      # Third configurable block to run. Does not run if +config.cache_classes+
+      # Third configurable block to run. Does not run if +config.eager_load+
       # set to false.
       def before_eager_load(&block)
         ActiveSupport.on_load(:before_eager_load, yield: true, &block)
diff --git a/railties/lib/rails/secrets.rb b/railties/lib/rails/secrets.rb
index aea72b2d01..30e3478c9b 100644
--- a/railties/lib/rails/secrets.rb
+++ b/railties/lib/rails/secrets.rb
@@ -32,23 +32,10 @@ module Rails
         end
       end
 
-      def generate_key
-        SecureRandom.hex(OpenSSL::Cipher.new(@cipher).key_len)
-      end
-
       def key
         ENV["RAILS_MASTER_KEY"] || read_key_file || handle_missing_key
       end
 
-      def template
-        <<-end_of_template.strip_heredoc
-          # See `secrets.yml` for tips on generating suitable keys.
-          # production:
-          #   external_api_key: 1466aac22e6a869134be3d09b9e89232fc2c2289
-
-        end_of_template
-      end
-
       def encrypt(data)
         encryptor.encrypt_and_sign(data)
       end
@@ -70,10 +57,6 @@ module Rails
         writing(read, &block)
       end
 
-      def read_template_for_editing(&block)
-        writing(template, &block)
-      end
-
       private
         def handle_missing_key
           raise MissingKeyError
diff --git a/railties/lib/rails/tasks/engine.rake b/railties/lib/rails/tasks/engine.rake
index c24d1ad532..8d77904210 100644
--- a/railties/lib/rails/tasks/engine.rake
+++ b/railties/lib/rails/tasks/engine.rake
@@ -53,7 +53,7 @@ namespace :db do
   desc "Rolls the schema back to the previous version (specify steps w/ STEP=n)."
   app_task "rollback"
 
-  desc "Create a db/schema.rb file that can be portably used against any DB supported by Active Record"
+  desc "Create a db/schema.rb file that can be portably used against any database supported by Active Record"
   app_task "schema:dump"
 
   desc "Load a schema.rb file into the database"
@@ -62,7 +62,7 @@ namespace :db do
   desc "Load the seed data from db/seeds.rb"
   app_task "seed"
 
-  desc "Create the database, load the schema, and initialize with the seed data (use db:reset to also drop the db first)"
+  desc "Create the database, load the schema, and initialize with the seed data (use db:reset to also drop the database first)"
   app_task "setup"
 
   desc "Dump the database structure to an SQL file"
@@ -70,6 +70,9 @@ namespace :db do
 
   desc "Retrieves the current schema version number"
   app_task "version"
+
+  # desc 'Load the test schema'
+  app_task "test:prepare"
 end
 
 def find_engine_path(path)
diff --git a/railties/lib/rails/templates/rails/mailers/email.html.erb b/railties/lib/rails/templates/rails/mailers/email.html.erb
index 89c1129f90..2a41c29602 100644
--- a/railties/lib/rails/templates/rails/mailers/email.html.erb
+++ b/railties/lib/rails/templates/rails/mailers/email.html.erb
@@ -95,11 +95,25 @@
       </dd>
     <% end %>
 
+    <dt>Format:</dt>
     <% if @email.multipart? %>
       <dd>
-        <select onchange="formatChanged(this);">
-          <option <%= request.format == Mime[:html] ? 'selected' : '' %> value="?<%= part_query('text/html') %>">View as HTML email</option>
-          <option <%= request.format == Mime[:text] ? 'selected' : '' %> value="?<%= part_query('text/plain') %>">View as plain-text email</option>
+        <select id="part" onchange="refreshBody();">
+          <option <%= request.format == Mime[:html] ? 'selected' : '' %> value="<%= part_query('text/html') %>">View as HTML email</option>
+          <option <%= request.format == Mime[:text] ? 'selected' : '' %> value="<%= part_query('text/plain') %>">View as plain-text email</option>
+        </select>
+      </dd>
+    <% else %>
+      <dd id="mime_type" data-mime-type="<%= part_query(@email.mime_type) %>"><%= @email.mime_type == 'text/html' ? 'HTML email' : 'plain-text email' %></dd>
+    <% end %>
+
+    <% if I18n.available_locales.count > 1 %>
+      <dt>Locale:</dt>
+      <dd>
+        <select id="locale" onchange="refreshBody();">
+          <% I18n.available_locales.each do |locale| %>
+            <option <%= I18n.locale == locale ? 'selected' : '' %> value="<%= locale_query(locale) %>"><%= locale %></option>
+          <% end %>
         </select>
       </dd>
     <% end %>
@@ -116,15 +130,27 @@
 <% end %>
 
 <script>
-  function formatChanged(form) {
-    var part_name = form.options[form.selectedIndex].value
-    var iframe =document.getElementsByName('messageBody')[0];
-    iframe.contentWindow.location.replace(part_name);
+  function refreshBody() {
+    var part_select = document.querySelector('select#part');
+    var locale_select = document.querySelector('select#locale');
+    var iframe = document.getElementsByName('messageBody')[0];
+    var part_param = part_select ?
+      part_select.options[part_select.selectedIndex].value :
+      document.querySelector('#mime_type').dataset.mimeType;
+    var locale_param = locale_select ? locale_select.options[locale_select.selectedIndex].value : null;
+    var fresh_location;
+    if (locale_param) {
+      fresh_location = '?' + part_param + '&' + locale_param;
+    } else {
+      fresh_location = '?' + part_param;
+    }
+    iframe.contentWindow.location = fresh_location;
 
     if (history.replaceState) {
-      var url    = location.pathname.replace(/\.(txt|html)$/, '');
-      var format = /html/.test(part_name) ? '.html' : '.txt';
-      window.history.replaceState({}, '', url + format);
+      var url = location.pathname.replace(/\.(txt|html)$/, '');
+      var format = /html/.test(part_param) ? '.html' : '.txt';
+      var state_to_replace = locale_param ? (url + format + '?' + locale_param) : (url + format);
+      window.history.replaceState({}, '', state_to_replace);
     }
   }
 </script>
diff --git a/railties/lib/rails/test_help.rb b/railties/lib/rails/test_help.rb
index 732c5c1e1f..76c28ac85e 100644
--- a/railties/lib/rails/test_help.rb
+++ b/railties/lib/rails/test_help.rb
@@ -29,10 +29,6 @@ if defined?(ActiveRecord::Base)
   end
 
   ActionDispatch::IntegrationTest.fixture_path = ActiveSupport::TestCase.fixture_path
-
-  def create_fixtures(*fixture_set_names, &block)
-    FixtureSet.create_fixtures(ActiveSupport::TestCase.fixture_path, fixture_set_names, {}, &block)
-  end
 end
 
 # :enddoc:
diff --git a/railties/lib/rails/test_unit/reporter.rb b/railties/lib/rails/test_unit/reporter.rb
index 7d3164f1eb..28b93cee5a 100644
--- a/railties/lib/rails/test_unit/reporter.rb
+++ b/railties/lib/rails/test_unit/reporter.rb
@@ -64,11 +64,17 @@ module Rails
       end
 
       def format_line(result)
-        "%s#%s = %.2f s = %s" % [result.class, result.name, result.time, result.result_code]
+        klass = result.respond_to?(:klass) ? result.klass : result.class
+        "%s#%s = %.2f s = %s" % [klass, result.name, result.time, result.result_code]
       end
 
       def format_rerun_snippet(result)
-        location, line = result.method(result.name).source_location
+        location, line = if result.respond_to?(:source_location)
+          result.source_location
+        else
+          result.method(result.name).source_location
+        end
+
         "#{executable} #{relative_path_for(location)}:#{line}"
       end
 
diff --git a/railties/lib/rails/test_unit/runner.rb b/railties/lib/rails/test_unit/runner.rb
index 5c2f6451e2..de5744c662 100644
--- a/railties/lib/rails/test_unit/runner.rb
+++ b/railties/lib/rails/test_unit/runner.rb
@@ -13,7 +13,7 @@ module Rails
       class << self
         def attach_before_load_options(opts)
           opts.on("--warnings", "-w", "Run with Ruby warnings enabled") {}
-          opts.on("--environment", "-e", "Run tests in the ENV environment") {}
+          opts.on("-e", "--environment ENV", "Run tests in the ENV environment") {}
         end
 
         def parse_options(argv)