1 files changed, 131 insertions, 0 deletions
diff --git a/railties/lib/rails/configuration.rb b/railties/lib/rails/configuration.rb
new file mode 100644
index 0000000000..e8741a50ba
--- /dev/null
+++ b/railties/lib/rails/configuration.rb
@@ -0,0 +1,131 @@
+# frozen_string_literal: true
+
+require "active_support/ordered_options"
+require "active_support/core_ext/object"
+require "rails/paths"
+require "rails/rack"
+
+module Rails
+  module Configuration
+    # MiddlewareStackProxy is a proxy for the Rails middleware stack that allows
+    # you to configure middlewares in your application. It works basically as a
+    # command recorder, saving each command to be applied after initialization
+    # over the default middleware stack, so you can add, swap, or remove any
+    # middleware in Rails.
+    #
+    # You can add your own middlewares by using the +config.middleware.use+ method:
+    #
+    #     config.middleware.use Magical::Unicorns
+    #
+    # This will put the <tt>Magical::Unicorns</tt> middleware on the end of the stack.
+    # You can use +insert_before+ if you wish to add a middleware before another:
+    #
+    #     config.middleware.insert_before Rack::Head, Magical::Unicorns
+    #
+    # There's also +insert_after+ which will insert a middleware after another:
+    #
+    #     config.middleware.insert_after Rack::Head, Magical::Unicorns
+    #
+    # Middlewares can also be completely swapped out and replaced with others:
+    #
+    #     config.middleware.swap ActionDispatch::Flash, Magical::Unicorns
+    #
+    # And finally they can also be removed from the stack completely:
+    #
+    #     config.middleware.delete ActionDispatch::Flash
+    #
+    class MiddlewareStackProxy
+      def initialize(operations = [], delete_operations = [])
+        @operations = operations
+        @delete_operations = delete_operations
+      end
+
+      def insert_before(*args, &block)
+        @operations << [__method__, args, block]
+      end
+
+      alias :insert :insert_before
+
+      def insert_after(*args, &block)
+        @operations << [__method__, args, block]
+      end
+
+      def swap(*args, &block)
+        @operations << [__method__, args, block]
+      end
+
+      def use(*args, &block)
+        @operations << [__method__, args, block]
+      end
+
+      def delete(*args, &block)
+        @delete_operations << [__method__, args, block]
+      end
+
+      def unshift(*args, &block)
+        @operations << [__method__, args, block]
+      end
+
+      def merge_into(other) #:nodoc:
+        (@operations + @delete_operations).each do |operation, args, block|
+          other.send(operation, *args, &block)
+        end
+
+        other
+      end
+
+      def +(other) # :nodoc:
+        MiddlewareStackProxy.new(@operations + other.operations, @delete_operations + other.delete_operations)
+      end
+
+      protected
+        attr_reader :operations, :delete_operations
+    end
+
+    class Generators #:nodoc:
+      attr_accessor :aliases, :options, :templates, :fallbacks, :colorize_logging, :api_only
+      attr_reader :hidden_namespaces
+
+      def initialize
+        @aliases = Hash.new { |h, k| h[k] = {} }
+        @options = Hash.new { |h, k| h[k] = {} }
+        @fallbacks = {}
+        @templates = []
+        @colorize_logging = true
+        @api_only = false
+        @hidden_namespaces = []
+      end
+
+      def initialize_copy(source)
+        @aliases = @aliases.deep_dup
+        @options = @options.deep_dup
+        @fallbacks = @fallbacks.deep_dup
+        @templates = @templates.dup
+      end
+
+      def hide_namespace(namespace)
+        @hidden_namespaces << namespace
+      end
+
+      def method_missing(method, *args)
+        method = method.to_s.sub(/=$/, "").to_sym
+
+        return @options[method] if args.empty?
+
+        if method == :rails || args.first.is_a?(Hash)
+          namespace, configuration = method, args.shift
+        else
+          namespace, configuration = args.shift, args.shift
+          namespace = namespace.to_sym if namespace.respond_to?(:to_sym)
+          @options[:rails][method] = namespace
+        end
+
+        if configuration
+          aliases = configuration.delete(:aliases)
+          @aliases[namespace].merge!(aliases) if aliases
+          @options[namespace].merge!(configuration)
+        end
+      end
+    end
+  end
+end