Use `Mime[:foo]` instead of `Mime::Type[:FOO]` for back compat

Rails 4.x and earlier didn't support `Mime::Type[:FOO]`, so libraries
that support multiple Rails versions would've had to feature-detect
whether to use `Mime::Type[:FOO]` or `Mime::FOO`.

`Mime[:foo]` has been around for ages to look up registered MIME types
by symbol / extension, though, so libraries and plugins can safely
switch to that without breaking backward- or forward-compatibility.

Note: `Mime::ALL` isn't a real MIME type and isn't registered for lookup
by type or extension, so it's not available as `Mime[:all]`. We use it
internally as a wildcard for `respond_to` negotiation. If you use this
internal constant, continue to reference it with `Mime::ALL`.

Ref. efc6dd550ee49e7e443f9d72785caa0f240def53

14 files changed, 69 insertions, 79 deletions

diff --git a/actionpack/lib/abstract_controller/collector.rb b/actionpack/lib/abstract_controller/collector.rb
index 3b5128cda5..55654be224 100644
--- a/actionpack/lib/abstract_controller/collector.rb
+++ b/actionpack/lib/abstract_controller/collector.rb
@@ -4,11 +4,10 @@ module AbstractController
   module Collector
     def self.generate_method_for_mime(mime)
       sym = mime.is_a?(Symbol) ? mime : mime.to_sym
-      const = sym.upcase
       class_eval <<-RUBY, __FILE__, __LINE__ + 1
-        def #{sym}(*args, &block)                # def html(*args, &block)
-          custom(Mime::Type[:#{const}], *args, &block)  #   custom(Mime::Type[:HTML], *args, &block)
-        end                                      # end
+        def #{sym}(*args, &block)
+          custom(Mime[:#{sym}], *args, &block)
+        end
       RUBY
     end
 
@@ -23,9 +22,7 @@ module AbstractController
   protected
 
     def method_missing(symbol, &block)
-      const_name = symbol.upcase
-
-      unless Mime::Type.registered?(const_name)
+      unless mime_constant = Mime[symbol]
         raise NoMethodError, "To respond to a custom format, register it as a MIME type first: " \
           "http://guides.rubyonrails.org/action_controller_overview.html#restful-downloads. " \
           "If you meant to respond to a variant like :tablet or :phone, not a custom format, " \
@@ -33,8 +30,6 @@ module AbstractController
           "format.html { |html| html.tablet { ... } }"
       end
 
-      mime_constant = Mime::Type[const_name]
-
       if Mime::SET.include?(mime_constant)
         AbstractController::Collector.generate_method_for_mime(mime_constant)
         send(symbol, &block)
diff --git a/actionpack/lib/abstract_controller/rendering.rb b/actionpack/lib/abstract_controller/rendering.rb
index 824a383f79..a73f188623 100644
--- a/actionpack/lib/abstract_controller/rendering.rb
+++ b/actionpack/lib/abstract_controller/rendering.rb
@@ -55,7 +55,7 @@ module AbstractController
     # Returns Content-Type of rendered content
     # :api: public
     def rendered_format
-      Mime::Type[:TEXT]
+      Mime[:text]
     end
 
     DEFAULT_PROTECTED_INSTANCE_VARIABLES = Set.new %i(
diff --git a/actionpack/lib/action_controller/metal/http_authentication.rb b/actionpack/lib/action_controller/metal/http_authentication.rb
index fe470552b0..0a36fecd27 100644
--- a/actionpack/lib/action_controller/metal/http_authentication.rb
+++ b/actionpack/lib/action_controller/metal/http_authentication.rb
@@ -34,7 +34,7 @@ module ActionController
     #
     #       def authenticate
     #         case request.format
-    #         when Mime::Type[:XML], Mime::Type[:ATOM]
+    #         when Mime[:xml], Mime[:atom]
     #           if user = authenticate_with_http_basic { |u, p| @account.users.authenticate(u, p) }
     #             @current_user = user
     #           else
@@ -361,7 +361,7 @@ module ActionController
     #
     #       def authenticate
     #         case request.format
-    #         when Mime::Type[:XML], Mime::Type[:ATOM]
+    #         when Mime[:xml], Mime[:atom]
     #           if user = authenticate_with_http_token { |t, o| @account.users.authenticate(t, o) }
     #             @current_user = user
     #           else
diff --git a/actionpack/lib/action_controller/metal/mime_responds.rb b/actionpack/lib/action_controller/metal/mime_responds.rb
index fc42fe5c07..58df5c539e 100644
--- a/actionpack/lib/action_controller/metal/mime_responds.rb
+++ b/actionpack/lib/action_controller/metal/mime_responds.rb
@@ -229,14 +229,14 @@ module ActionController #:nodoc:
         @responses = {}
         @variant = variant
 
-        mimes.each { |mime| @responses[Mime::Type[mime.upcase.to_sym]] = nil }
+        mimes.each { |mime| @responses[Mime[mime]] = nil }
       end
 
       def any(*args, &block)
         if args.any?
           args.each { |type| send(type, &block) }
         else
-          custom(Mime::Type[:ALL], &block)
+          custom(Mime::ALL, &block)
         end
       end
       alias :all :any
@@ -251,7 +251,7 @@ module ActionController #:nodoc:
       end
 
       def response
-        response = @responses.fetch(format, @responses[Mime::Type[:ALL]])
+        response = @responses.fetch(format, @responses[Mime::ALL])
         if response.is_a?(VariantCollector) # `format.html.phone` - variant inline syntax
           response.variant
         elsif response.nil? || response.arity == 0 # `format.html` - just a format, call its block
diff --git a/actionpack/lib/action_controller/metal/renderers.rb b/actionpack/lib/action_controller/metal/renderers.rb
index d867c97b46..22e0bb5955 100644
--- a/actionpack/lib/action_controller/metal/renderers.rb
+++ b/actionpack/lib/action_controller/metal/renderers.rb
@@ -68,11 +68,11 @@ module ActionController
     #   ActionController::Renderers.add :csv do |obj, options|
     #     filename = options[:filename] || 'data'
     #     str = obj.respond_to?(:to_csv) ? obj.to_csv : obj.to_s
-    #     send_data str, type: Mime::Type[:CSV],
+    #     send_data str, type: Mime[:csv],
     #       disposition: "attachment; filename=#{filename}.csv"
     #   end
     #
-    # Note that we used Mime::Type[:CSV] for the csv mime type as it comes with Rails.
+    # Note that we used Mime[:csv] for the csv mime type as it comes with Rails.
     # For a custom renderer, you'll need to register a mime type with
     # <tt>Mime::Type.register</tt>.
     #
@@ -116,24 +116,24 @@ module ActionController
       json = json.to_json(options) unless json.kind_of?(String)
 
       if options[:callback].present?
-        if content_type.nil? || content_type == Mime::Type[:JSON]
-          self.content_type = Mime::Type[:JS]
+        if content_type.nil? || content_type == Mime[:json]
+          self.content_type = Mime[:js]
         end
 
         "/**/#{options[:callback]}(#{json})"
       else
-        self.content_type ||= Mime::Type[:JSON]
+        self.content_type ||= Mime[:json]
         json
       end
     end
 
     add :js do |js, options|
-      self.content_type ||= Mime::Type[:JS]
+      self.content_type ||= Mime[:js]
       js.respond_to?(:to_js) ? js.to_js(options) : js
     end
 
     add :xml do |xml, options|
-      self.content_type ||= Mime::Type[:XML]
+      self.content_type ||= Mime[:xml]
       xml.respond_to?(:to_xml) ? xml.to_xml(options) : xml
     end
   end
diff --git a/actionpack/lib/action_controller/metal/rendering.rb b/actionpack/lib/action_controller/metal/rendering.rb
index 1ecccf9864..172fbdf954 100644
--- a/actionpack/lib/action_controller/metal/rendering.rb
+++ b/actionpack/lib/action_controller/metal/rendering.rb
@@ -64,7 +64,7 @@ module ActionController
     end
 
     def _set_html_content_type
-      self.content_type = Mime::Type[:HTML].to_s
+      self.content_type = Mime[:html].to_s
     end
 
     def _set_rendered_content_type(format)
diff --git a/actionpack/lib/action_controller/test_case.rb b/actionpack/lib/action_controller/test_case.rb
index cf78688126..380e9d29b4 100644
--- a/actionpack/lib/action_controller/test_case.rb
+++ b/actionpack/lib/action_controller/test_case.rb
@@ -34,7 +34,7 @@ module ActionController
       self.session = session
       self.session_options = TestSession::DEFAULT_OPTIONS
       @custom_param_parsers = {
-        Mime::Type[:XML] => lambda { |raw_post| Hash.from_xml(raw_post)['hash'] }
+        Mime[:xml] => lambda { |raw_post| Hash.from_xml(raw_post)['hash'] }
       }
     end
 
@@ -402,7 +402,7 @@ module ActionController
         MSG
 
         @request.env['HTTP_X_REQUESTED_WITH'] = 'XMLHttpRequest'
-        @request.env['HTTP_ACCEPT'] ||= [Mime::Type[:JS], Mime::Type[:HTML], Mime::Type[:XML], 'text/xml', Mime::Type[:ALL]].join(', ')
+        @request.env['HTTP_ACCEPT'] ||= [Mime[:js], Mime[:html], Mime[:xml], 'text/xml', '*/*'].join(', ')
         __send__(*args).tap do
           @request.env.delete 'HTTP_X_REQUESTED_WITH'
           @request.env.delete 'HTTP_ACCEPT'
@@ -505,7 +505,7 @@ module ActionController
         if xhr
           @request.set_header 'HTTP_X_REQUESTED_WITH', 'XMLHttpRequest'
           @request.fetch_header('HTTP_ACCEPT') do |k|
-            @request.set_header k, [Mime::Type[:JS], Mime::Type[:HTML], Mime::Type[:XML], 'text/xml', Mime::Type[:ALL]].join(', ')
+            @request.set_header k, [Mime[:js], Mime[:html], Mime[:xml], 'text/xml', '*/*'].join(', ')
           end
         end
 
diff --git a/actionpack/lib/action_dispatch/http/mime_negotiation.rb b/actionpack/lib/action_dispatch/http/mime_negotiation.rb
index a966c5e452..7acf91902d 100644
--- a/actionpack/lib/action_dispatch/http/mime_negotiation.rb
+++ b/actionpack/lib/action_dispatch/http/mime_negotiation.rb
@@ -10,7 +10,7 @@ module ActionDispatch
         self.ignore_accept_header = false
       end
 
-      # The MIME type of the HTTP request, such as Mime::Type[:XML].
+      # The MIME type of the HTTP request, such as Mime[:xml].
       #
       # For backward compatibility, the post \format is extracted from the
       # X-Post-Data-Format HTTP header if present.
@@ -49,9 +49,9 @@ module ActionDispatch
 
       # Returns the MIME type for the \format used in the request.
       #
-      #   GET /posts/5.xml   | request.format => Mime::Type[:XML]
-      #   GET /posts/5.xhtml | request.format => Mime::Type[:HTML]
-      #   GET /posts/5       | request.format => Mime::Type[:HTML] or Mime::Type[:JS], or request.accepts.first
+      #   GET /posts/5.xml   | request.format => Mime[:xml]
+      #   GET /posts/5.xhtml | request.format => Mime[:html]
+      #   GET /posts/5       | request.format => Mime[:html] or Mime[:js], or request.accepts.first
       #
       def format(view_path = [])
         formats.first || Mime::NullType.instance
@@ -70,9 +70,9 @@ module ActionDispatch
           elsif use_accept_header && valid_accept_header
             accepts
           elsif xhr?
-            [Mime::Type[:JS]]
+            [Mime[:js]]
           else
-            [Mime::Type[:HTML]]
+            [Mime[:html]]
           end
           set_header k, v
         end
@@ -138,14 +138,14 @@ module ActionDispatch
       #
       def negotiate_mime(order)
         formats.each do |priority|
-          if priority == Mime::Type[:ALL]
+          if priority == Mime::ALL
             return order.first
           elsif order.include?(priority)
             return priority
           end
         end
 
-        order.include?(Mime::Type[:ALL]) ? format : nil
+        order.include?(Mime::ALL) ? format : nil
       end
 
       protected
diff --git a/actionpack/lib/action_dispatch/http/mime_type.rb b/actionpack/lib/action_dispatch/http/mime_type.rb
index 36e90e5855..95094c25c0 100644
--- a/actionpack/lib/action_dispatch/http/mime_type.rb
+++ b/actionpack/lib/action_dispatch/http/mime_type.rb
@@ -46,7 +46,8 @@ module Mime
     end
 
     def const_missing(sym)
-      if Mime::Type.registered?(sym)
+      ext = sym.downcase
+      if Mime[ext]
         ActiveSupport::Deprecation.warn <<-eow
 Accessing mime types via constants is deprecated.  Please change:
 
@@ -54,16 +55,17 @@ Accessing mime types via constants is deprecated.  Please change:
 
 to:
 
-  `Mime::Type[:#{sym}]`
+  `Mime[:#{ext}]`
         eow
-        Mime::Type[sym]
+        Mime[ext]
       else
         super
       end
     end
 
     def const_defined?(sym, inherit = true)
-      if Mime::Type.registered?(sym)
+      ext = sym.downcase
+      if Mime[ext]
         ActiveSupport::Deprecation.warn <<-eow
 Accessing mime types via constants is deprecated.  Please change:
 
@@ -71,7 +73,7 @@ Accessing mime types via constants is deprecated.  Please change:
 
 to:
 
-  `Mime::Type.registered?(:#{sym})`
+  `Mime[:#{ext}]`
         eow
         true
       else
@@ -106,7 +108,7 @@ to:
       def initialize(index, name, q = nil)
         @index = index
         @name = name
-        q ||= 0.0 if @name == Mime::Type[:ALL].to_s # default wildcard match to end of list
+        q ||= 0.0 if @name == '*/*'.freeze # default wildcard match to end of list
         @q = ((q || 1.0).to_f * 100).to_i
       end
 
@@ -131,7 +133,7 @@ to:
           exchange_xml_items if app_xml_idx > text_xml_idx  # make sure app_xml is ahead of text_xml in the list
           delete_at(text_xml_idx)                 # delete text_xml from the list
         elsif text_xml_idx
-          text_xml.name = Mime::Type[:XML].to_s
+          text_xml.name = Mime[:xml].to_s
         end
 
         # Look for more specific XML-based types and sort them ahead of app/xml
@@ -160,7 +162,7 @@ to:
         end
 
         def app_xml_idx
-          @app_xml_idx ||= index(Mime::Type[:XML].to_s)
+          @app_xml_idx ||= index(Mime[:xml].to_s)
         end
 
         def text_xml
@@ -177,8 +179,6 @@ to:
         end
     end
 
-    TYPES = {}
-
     class << self
       TRAILING_STAR_REGEXP = /(text|application)\/\*/
       PARAMETER_SEPARATOR_REGEXP = /;\s*\w+="?\w+"?/
@@ -187,18 +187,6 @@ to:
         @register_callbacks << block
       end
 
-      def registered?(symbol)
-        TYPES.key? symbol
-      end
-
-      def [](symbol)
-        TYPES[symbol]
-      end
-
-      def add_type(symbol, type)
-        TYPES[symbol] = type
-      end
-
       def lookup(string)
         LOOKUP[string]
       end
@@ -215,7 +203,6 @@ to:
 
       def register(string, symbol, mime_type_synonyms = [], extension_synonyms = [], skip_lookup = false)
         new_mime = Type.new(string, symbol, mime_type_synonyms)
-        add_type symbol.upcase, new_mime
 
         SET << new_mime
 
@@ -255,13 +242,13 @@ to:
         parse_data_with_trailing_star($1) if accept_header =~ TRAILING_STAR_REGEXP
       end
 
-      # For an input of <tt>'text'</tt>, returns <tt>[Mime::Type[:JSON], Mime::Type[:XML], Mime::Type[:ICS],
-      # Mime::Type[:HTML], Mime::Type[:CSS], Mime::Type[:CSV], Mime::Type[:JS], Mime::Type[:YAML], Mime::Type[:TEXT]</tt>.
+      # For an input of <tt>'text'</tt>, returns <tt>[Mime[:json], Mime[:xml], Mime[:ics],
+      # Mime[:html], Mime[:css], Mime[:csv], Mime[:js], Mime[:yaml], Mime[:text]</tt>.
       #
-      # For an input of <tt>'application'</tt>, returns <tt>[Mime::Type[:HTML], Mime::Type[:JS],
-      # Mime::Type[:XML], Mime::Type[:YAML], Mime::Type[:ATOM], Mime::Type[:JSON], Mime::Type[:RSS], Mime::Type[:URL_ENCODED_FORM]</tt>.
-      def parse_data_with_trailing_star(input)
-        Mime::SET.select { |m| m =~ input }
+      # For an input of <tt>'application'</tt>, returns <tt>[Mime[:html], Mime[:js],
+      # Mime[:xml], Mime[:yaml], Mime[:atom], Mime[:json], Mime[:rss], Mime[:url_encoded_form]</tt>.
+      def parse_data_with_trailing_star(type)
+        Mime::SET.select { |m| m =~ type }
       end
 
       # This method is opposite of register method.
@@ -270,12 +257,12 @@ to:
       #
       #   Mime::Type.unregister(:mobile)
       def unregister(symbol)
-        symbol = symbol.upcase
-        mime = TYPES.delete symbol
-
-        SET.delete_if { |v| v.eql?(mime) }
-        LOOKUP.delete_if { |_,v| v.eql?(mime) }
-        EXTENSION_LOOKUP.delete_if { |_,v| v.eql?(mime) }
+        symbol = symbol.downcase
+        if mime = Mime[symbol]
+          SET.delete_if { |v| v.eql?(mime) }
+          LOOKUP.delete_if { |_, v| v.eql?(mime) }
+          EXTENSION_LOOKUP.delete_if { |_, v| v.eql?(mime) }
+        end
       end
     end
 
@@ -343,13 +330,24 @@ to:
     def respond_to_missing?(method, include_private = false) #:nodoc:
       method.to_s.ends_with? '?'
     end
+  end
+
+  class AllType < Type
+    include Singleton
 
-    class All < Type
-      def all?; true; end
-      def html?; true; end
+    def initialize
+      super '*/*', :all
     end
+
+    def all?; true; end
+    def html?; true; end
   end
 
+  # ALL isn't a real MIME type, so we don't register it for lookup with the
+  # other concrete types. It's a wildcard match that we use for `respond_to`
+  # negotiation internals.
+  ALL = AllType.instance
+
   class NullType
     include Singleton
 
diff --git a/actionpack/lib/action_dispatch/http/mime_types.rb b/actionpack/lib/action_dispatch/http/mime_types.rb
index 04828f7c87..87715205d9 100644
--- a/actionpack/lib/action_dispatch/http/mime_types.rb
+++ b/actionpack/lib/action_dispatch/http/mime_types.rb
@@ -31,6 +31,3 @@ Mime::Type.register "application/json", :json, %w( text/x-json application/jsonr
 
 Mime::Type.register "application/pdf", :pdf, [], %w(pdf)
 Mime::Type.register "application/zip", :zip, [], %w(zip)
-
-# Create Mime::Type[:ALL] but do not add it to the SET.
-Mime::Type.add_type :ALL, Mime::Type::All.new("*/*", :all, [])
diff --git a/actionpack/lib/action_dispatch/http/parameters.rb b/actionpack/lib/action_dispatch/http/parameters.rb
index e3c4392760..248ecfd676 100644
--- a/actionpack/lib/action_dispatch/http/parameters.rb
+++ b/actionpack/lib/action_dispatch/http/parameters.rb
@@ -4,7 +4,7 @@ module ActionDispatch
       PARAMETERS_KEY = 'action_dispatch.request.path_parameters'
 
       DEFAULT_PARSERS = {
-        Mime::Type[:JSON] => lambda { |raw_post|
+        Mime[:json] => lambda { |raw_post|
           data = ActiveSupport::JSON.decode(raw_post)
           data.is_a?(Hash) ? data : {:_json => data}
         }
diff --git a/actionpack/lib/action_dispatch/http/response.rb b/actionpack/lib/action_dispatch/http/response.rb
index d4a534d892..e8cff9a73a 100644
--- a/actionpack/lib/action_dispatch/http/response.rb
+++ b/actionpack/lib/action_dispatch/http/response.rb
@@ -427,7 +427,7 @@ module ActionDispatch # :nodoc:
       return if content_type
 
       ct = parse_content_type
-      set_content_type(ct.mime_type || Mime::Type[:HTML].to_s,
+      set_content_type(ct.mime_type || Mime[:html].to_s,
                        ct.charset || self.class.default_charset)
     end
 
diff --git a/actionpack/lib/action_dispatch/testing/assertions.rb b/actionpack/lib/action_dispatch/testing/assertions.rb
index 81fa10a613..8dd0bd63ad 100644
--- a/actionpack/lib/action_dispatch/testing/assertions.rb
+++ b/actionpack/lib/action_dispatch/testing/assertions.rb
@@ -12,7 +12,7 @@ module ActionDispatch
     include Rails::Dom::Testing::Assertions
 
     def html_document
-      @html_document ||= if @response.content_type === Mime::Type[:XML]
+      @html_document ||= if @response.content_type === Mime[:xml]
         Nokogiri::XML::Document.parse(@response.body)
       else
         Nokogiri::HTML::Document.parse(@response.body)
diff --git a/actionpack/lib/action_dispatch/testing/integration.rb b/actionpack/lib/action_dispatch/testing/integration.rb
index 753cd2073b..7e59bb68cf 100644
--- a/actionpack/lib/action_dispatch/testing/integration.rb
+++ b/actionpack/lib/action_dispatch/testing/integration.rb
@@ -354,7 +354,7 @@ module ActionDispatch
           if xhr
             headers ||= {}
             headers['HTTP_X_REQUESTED_WITH'] = 'XMLHttpRequest'
-            headers['HTTP_ACCEPT'] ||= [Mime::Type[:JS], Mime::Type[:HTML], Mime::Type[:XML], 'text/xml', Mime::Type[:ALL]].join(', ')
+            headers['HTTP_ACCEPT'] ||= [Mime[:js], Mime[:html], Mime[:xml], 'text/xml', '*/*'].join(', ')
           end
 
           # this modifies the passed request_env directly