Merge pull request rails#42652 from ghiculescu/remove-local-cache-middleware

Allow removing LocalCache middleware in application.rb

Author: byroot

actionpack/lib/action_dispatch/middleware/stack.rb

@@ -130,7 +130,7 @@ def swap(target, *args, &block)
     ruby2_keywords(:swap)
 
     def delete(target)
-      middlewares.delete_if { |m| m.klass == target }
+      middlewares.delete_if { |m| m.name == target.name }
     end
 
     def move(target, source)
@@ -180,10 +180,10 @@ def build_middleware(klass, args, block)
         Middleware.new(klass, args, block)
       end
 
-      def index_of(index)
-        raise "ActionDispatch::MiddlewareStack::FakeRuntime can not be referenced in middleware operations" if index == FakeRuntime
+      def index_of(klass)
+        raise "ActionDispatch::MiddlewareStack::FakeRuntime can not be referenced in middleware operations" if klass == FakeRuntime
 
-        if index == Rack::Runtime && @rack_runtime_deprecated
+        if klass == Rack::Runtime && @rack_runtime_deprecated
           ActiveSupport::Deprecation.warn(<<-MSG.squish)
             Rack::Runtime is removed from the default middleware stack in Rails
             and referencing it in middleware operations without adding it back
@@ -192,7 +192,7 @@ def index_of(index)
         end
 
         middlewares.index do |m|
-          m.klass == index || (@rack_runtime_deprecated && m.klass == FakeRuntime && index == Rack::Runtime)
+          m.name == klass.name || (@rack_runtime_deprecated && m.klass == FakeRuntime && klass == Rack::Runtime)
         end
       end
   end

railties/test/application/configuration_test.rb

@@ -3226,6 +3226,97 @@ class MyLogger < ::Logger
       assert_no_match(/You are running SQLite in production, this is generally not recommended/, Rails.logger.recording)
     end
 
+    test "app starts with LocalCache middleware" do
+      app "development"
+
+      assert(Rails.application.config.middleware.map(&:name).include?("ActiveSupport::Cache::Strategy::LocalCache"))
+
+      local_cache_index = Rails.application.config.middleware.map(&:name).index("ActiveSupport::Cache::Strategy::LocalCache")
+      logger_index = Rails.application.config.middleware.map(&:name).index("Rails::Rack::Logger")
+      assert local_cache_index < logger_index
+    end
+
+    test "LocalCache middleware can be moved via app config" do
+      # you can't move Rails.cache.middleware as it doesn't exist yet
+      add_to_config "config.middleware.move_after(Rails::Rack::Logger, ActiveSupport::Cache::Strategy::LocalCache)"
+
+      app "development"
+
+      local_cache_index = Rails.application.config.middleware.map(&:name).index("ActiveSupport::Cache::Strategy::LocalCache")
+      logger_index = Rails.application.config.middleware.map(&:name).index("Rails::Rack::Logger")
+      assert local_cache_index > logger_index
+    end
+
+    test "LocalCache middleware can be moved via initializer" do
+      app_file "config/initializers/move_local_cache_middleware.rb", <<~RUBY
+        Rails.application.config.middleware.move_after(Rails::Rack::Logger, Rails.cache.middleware)
+      RUBY
+
+      app "development"
+
+      local_cache_index = Rails.application.config.middleware.map(&:name).index("ActiveSupport::Cache::Strategy::LocalCache")
+      logger_index = Rails.application.config.middleware.map(&:name).index("Rails::Rack::Logger")
+      assert local_cache_index > logger_index
+    end
+
+    test "LocalCache middleware can be removed via app config" do
+      # you can't delete Rails.cache.middleware as it doesn't exist yet
+      add_to_config "config.middleware.delete(ActiveSupport::Cache::Strategy::LocalCache)"
+
+      app "development"
+
+      assert_not(Rails.application.config.middleware.map(&:name).include?("ActiveSupport::Cache::Strategy::LocalCache"))
+    end
+
+    test "LocalCache middleware can be removed via initializer" do
+      app_file "config/initializers/remove_local_cache_middleware.rb", <<~RUBY
+        Rails.application.config.middleware.delete(Rails.cache.middleware)
+      RUBY
+
+      app "development"
+
+      assert_not(Rails.application.config.middleware.map(&:name).include?("ActiveSupport::Cache::Strategy::LocalCache"))
+    end
+
+    test "custom middleware with overridden names can be added, moved, or deleted" do
+      app_file "config/initializers/add_custom_middleware.rb", <<~RUBY
+        class CustomMiddlewareOne
+          def self.name
+            "1st custom middleware"
+          end
+          def initialize(app, *args); end
+          def new(app); self; end
+        end
+
+        class CustomMiddlewareTwo
+          def initialize(app, *args); end
+          def new(app); self; end
+        end
+
+        class CustomMiddlewareThree
+          def self.name
+            "3rd custom middleware"
+          end
+          def initialize(app, *args); end
+          def new(app); self; end
+        end
+
+        Rails.application.config.middleware.use(CustomMiddlewareOne)
+        Rails.application.config.middleware.use(CustomMiddlewareTwo)
+        Rails.application.config.middleware.use(CustomMiddlewareThree)
+        Rails.application.config.middleware.move_after(CustomMiddlewareTwo, CustomMiddlewareOne)
+        Rails.application.config.middleware.delete(CustomMiddlewareThree)
+      RUBY
+
+      app "development"
+
+      custom_middleware_one = Rails.application.config.middleware.map(&:name).index("1st custom middleware")
+      custom_middleware_two = Rails.application.config.middleware.map(&:name).index("CustomMiddlewareTwo")
+      assert custom_middleware_one > custom_middleware_two
+
+      assert_nil Rails.application.config.middleware.map(&:name).index("3rd custom middleware")
+    end
+
     private
       def set_custom_config(contents, config_source = "custom".inspect)
         app_file "config/custom.yml", contents