Move content-type helpers from Middleware::Base into PrecomputedContentTypes

CHANGELOG.md

@@ -32,6 +32,7 @@
 * [#2710](https://github.com/ruby-grape/grape/pull/2710): Tidy up `Grape::DeclaredParamsHandler` - [@ericproulx](https://github.com/ericproulx).
 * [#2714](https://github.com/ruby-grape/grape/pull/2714): Drop unused `Grape::Middleware::Globals` and its `grape.request*` env constants - [@ericproulx](https://github.com/ericproulx).
 * [#2717](https://github.com/ruby-grape/grape/pull/2717): Convert `Grape::Exceptions::ErrorResponse` to a `Data` value object - [@ericproulx](https://github.com/ericproulx).
+* [#2719](https://github.com/ruby-grape/grape/pull/2719): Move content-type helpers from `Middleware::Base` into `PrecomputedContentTypes` - [@ericproulx](https://github.com/ericproulx).
 * Your contribution here.
 
 #### Fixes

lib/grape/middleware/base.rb

@@ -61,22 +61,6 @@ def response
         @app_response = Rack::Response[*@app_response]
       end
 
-      def content_types
-        @content_types ||= Grape::ContentTypes.content_types_for(options[:content_types])
-      end
-
-      def mime_types
-        @mime_types ||= Grape::ContentTypes.mime_types_for(content_types)
-      end
-
-      def content_type_for(format)
-        content_types_indifferent_access[format]
-      end
-
-      def content_type
-        content_type_for(env[Grape::Env::API_FORMAT] || options[:format]) || 'text/html'
-      end
-
       def query_params
         rack_request.GET
       rescue *Grape::RACK_ERRORS
@@ -85,10 +69,6 @@ def query_params
 
       private
 
-      def content_types_indifferent_access
-        @content_types_indifferent_access ||= content_types.with_indifferent_access
-      end
-
       def merge_headers(response)
         return if @header.blank?
 

lib/grape/middleware/precomputed_content_types.rb

@@ -2,21 +2,44 @@
 
 module Grape
   module Middleware
-    # Include in a middleware subclass to warm the content-type caches on the
-    # parent instance at initialization. Per-request dups inherit the cached
-    # values via +dup+'s ivar copy, avoiding ~1 µs per request of
-    # +with_indifferent_access+ recomputation.
+    # Include in a middleware subclass that needs content-type negotiation.
+    # Provides +content_types+ / +mime_types+ / +content_type_for+ /
+    # +content_type+ resolved from +options[:content_types]+ and
+    # +options[:format]+, and warms those caches on the parent instance at
+    # initialization so per-request +dup+s inherit them (avoiding
+    # ~1 µs/request of +with_indifferent_access+ recomputation).
     #
-    # Opt-in: plain +Grape::Middleware::Base+ subclasses continue to compute
-    # +content_types+ / +mime_types+ / +content_type_for+ lazily on first
-    # access.
+    # Opt-in: plain +Grape::Middleware::Base+ subclasses that don't need
+    # content-type-aware helpers don't pay for them.
     module PrecomputedContentTypes
       def initialize(app, **options)
         super
         content_types
         mime_types
         content_types_indifferent_access
       end
+
+      def content_types
+        @content_types ||= Grape::ContentTypes.content_types_for(options[:content_types])
+      end
+
+      def mime_types
+        @mime_types ||= Grape::ContentTypes.mime_types_for(content_types)
+      end
+
+      def content_type_for(format)
+        content_types_indifferent_access[format]
+      end
+
+      def content_type
+        content_type_for(env[Grape::Env::API_FORMAT] || options[:format]) || 'text/html'
+      end
+
+      private
+
+      def content_types_indifferent_access
+        @content_types_indifferent_access ||= content_types.with_indifferent_access
+      end
     end
   end
 end