Avoid 'last arg as keyword param' warning when building user middleware on Ruby 2.7

faraday.gemspec

@@ -19,6 +19,7 @@ Gem::Specification.new do |spec|
   spec.required_ruby_version = '>= 2.4'
 
   spec.add_dependency 'multipart-post', '>= 1.2', '< 3'
+  spec.add_dependency 'ruby2_keywords'
 
   files = %w[CHANGELOG.md LICENSE.md README.md Rakefile examples lib spec]
   spec.files = `git ls-files -z #{files.join(' ')}`.split("\0")

lib/faraday/dependency_loader.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require 'ruby2_keywords'
+
 module Faraday
   # DependencyLoader helps Faraday adapters and middleware load dependencies.
   module DependencyLoader
@@ -13,7 +15,7 @@ def dependency(lib = nil)
       self.load_error = e
     end
 
-    def new(*)
+    ruby2_keywords def new(*)
       unless loaded?
         raise "missing dependency for #{self}: #{load_error.message}"
       end

lib/faraday/rack_builder.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require 'ruby2_keywords'
 require 'faraday/adapter_registry'
 
 module Faraday
@@ -27,7 +28,7 @@ class Handler
 
       attr_reader :name
 
-      def initialize(klass, *args, &block)
+      ruby2_keywords def initialize(klass, *args, &block)
         @name = klass.to_s
         REGISTRY.set(klass) if klass.respond_to?(:name)
         @args = args
@@ -89,7 +90,7 @@ def locked?
       @handlers.frozen?
     end
 
-    def use(klass, *args, &block)
+    ruby2_keywords def use(klass, *args, &block)
       if klass.is_a? Symbol
         use_symbol(Faraday::Middleware, klass, *args, &block)
       else
@@ -99,15 +100,15 @@ def use(klass, *args, &block)
       end
     end
 
-    def request(key, *args, &block)
+    ruby2_keywords def request(key, *args, &block)
       use_symbol(Faraday::Request, key, *args, &block)
     end
 
-    def response(key, *args, &block)
+    ruby2_keywords def response(key, *args, &block)
       use_symbol(Faraday::Response, key, *args, &block)
     end
 
-    def adapter(klass = NO_ARGUMENT, *args, &block)
+    ruby2_keywords def adapter(klass = NO_ARGUMENT, *args, &block)
       return @adapter if klass == NO_ARGUMENT
 
       klass = Faraday::Adapter.lookup_middleware(klass) if klass.is_a?(Symbol)
@@ -116,7 +117,7 @@ def adapter(klass = NO_ARGUMENT, *args, &block)
 
     ## methods to push onto the various positions in the stack:
 
-    def insert(index, *args, &block)
+    ruby2_keywords def insert(index, *args, &block)
       raise_if_locked
       index = assert_index(index)
       handler = self.class::Handler.new(*args, &block)
@@ -125,12 +126,12 @@ def insert(index, *args, &block)
 
     alias insert_before insert
 
-    def insert_after(index, *args, &block)
+    ruby2_keywords def insert_after(index, *args, &block)
       index = assert_index(index)
       insert(index + 1, *args, &block)
     end
 
-    def swap(index, *args, &block)
+    ruby2_keywords def swap(index, *args, &block)
       raise_if_locked
       index = assert_index(index)
       @handlers.delete_at(index)
@@ -234,7 +235,7 @@ def is_adapter?(klass) # rubocop:disable Naming/PredicateName
       klass.ancestors.include?(Faraday::Adapter)
     end
 
-    def use_symbol(mod, key, *args, &block)
+    ruby2_keywords def use_symbol(mod, key, *args, &block)
       use(mod.lookup_middleware(key), *args, &block)
     end
 

spec/faraday/rack_builder_spec.rb

@@ -193,4 +193,148 @@ class Broken < Faraday::Middleware
       end
     end
   end
+
+  context 'when middleware is added with named arguments' do
+    let(:conn) { Faraday::Connection.new {} }
+
+    let(:dog_middleware) do
+      Class.new(Faraday::Middleware) do
+        attr_accessor :name
+        def initialize(app, name:)
+          super(app)
+          @name = name
+        end
+      end
+    end
+    let(:dog) do
+      subject.handlers.find { |handler| handler == dog_middleware }.build
+    end
+
+    it 'adds a handler to construct middleware with options passed to use' do
+      subject.use dog_middleware, name: 'Rex'
+      expect { dog }.to_not output(
+        /warning: Using the last argument as keyword parameters is deprecated/
+      ).to_stderr
+      expect(dog.name).to eq('Rex')
+    end
+  end
+
+  context 'when a request adapter is added with named arguments' do
+    let(:conn) { Faraday::Connection.new {} }
+
+    let(:cat_request) do
+      Class.new(Faraday::Middleware) do
+        attr_accessor :name
+        def initialize(app, name:)
+          super(app)
+          @name = name
+        end
+      end
+    end
+    let(:cat) do
+      subject.handlers.find { |handler| handler == cat_request }.build
+    end
+
+    it 'adds a handler to construct request adapter with options passed to request' do
+      Faraday::Request.register_middleware cat_request: cat_request
+      subject.request :cat_request, name: 'Felix'
+      expect { cat }.to_not output(
+        /warning: Using the last argument as keyword parameters is deprecated/
+      ).to_stderr
+      expect(cat.name).to eq('Felix')
+    end
+  end
+
+  context 'when a response adapter is added with named arguments' do
+    let(:conn) { Faraday::Connection.new {} }
+
+    let(:fish_response) do
+      Class.new(Faraday::Response::Middleware) do
+        attr_accessor :name
+        def initialize(app, name:)
+          super(app)
+          @name = name
+        end
+      end
+    end
+    let(:fish) do
+      subject.handlers.find { |handler| handler == fish_response }.build
+    end
+
+    it 'adds a handler to construct response adapter with options passed to response' do
+      Faraday::Response.register_middleware fish_response: fish_response
+      subject.response :fish_response, name: 'Bubbles'
+      expect { fish }.to_not output(
+        /warning: Using the last argument as keyword parameters is deprecated/
+      ).to_stderr
+      expect(fish.name).to eq('Bubbles')
+    end
+  end
+
+  context 'when a plain adapter is added with named arguments' do
+    let(:conn) { Faraday::Connection.new {} }
+
+    let(:rabbit_adapter) do
+      Class.new(Faraday::Adapter) do
+        attr_accessor :name
+        def initialize(app, name:)
+          super(app)
+          @name = name
+        end
+      end
+    end
+    let(:rabbit) do
+      subject.adapter.build
+    end
+
+    it 'adds a handler to construct adapter with options passed to adapter' do
+      Faraday::Adapter.register_middleware rabbit_adapter: rabbit_adapter
+      subject.adapter :rabbit_adapter, name: 'Thumper'
+      expect { rabbit }.to_not output(
+        /warning: Using the last argument as keyword parameters is deprecated/
+      ).to_stderr
+      expect(rabbit.name).to eq('Thumper')
+    end
+  end
+
+  context 'when handlers are directly added or updated' do
+    let(:conn) { Faraday::Connection.new {} }
+
+    let(:rock_handler) do
+      Class.new do
+        attr_accessor :name
+        def initialize(_app, name:)
+          @name = name
+        end
+      end
+    end
+    let(:rock) do
+      subject.handlers.find { |handler| handler == rock_handler }.build
+    end
+
+    it 'adds a handler to construct adapter with options passed to insert' do
+      subject.insert 0, rock_handler, name: 'Stony'
+      expect { rock }.to_not output(
+        /warning: Using the last argument as keyword parameters is deprecated/
+      ).to_stderr
+      expect(rock.name).to eq('Stony')
+    end
+
+    it 'adds a handler with options passed to insert_after' do
+      subject.insert_after 0, rock_handler, name: 'Rocky'
+      expect { rock }.to_not output(
+        /warning: Using the last argument as keyword parameters is deprecated/
+      ).to_stderr
+      expect(rock.name).to eq('Rocky')
+    end
+
+    it 'adds a handler with options passed to swap' do
+      subject.insert 0, rock_handler, name: 'Flint'
+      subject.swap 0, rock_handler, name: 'Chert'
+      expect { rock }.to_not output(
+        /warning: Using the last argument as keyword parameters is deprecated/
+      ).to_stderr
+      expect(rock.name).to eq('Chert')
+    end
+  end
 end