Merge pull request #804 from cavinkwon/add_respond_to_missing_to_async

Add respond_to_missing? for async/await

lib/concurrent/async.rb

@@ -333,6 +333,13 @@ def method_missing(method, *args, &block)
         ivar
       end
 
+      # Check whether the method is responsive
+      #
+      # @param [Symbol] method the method being called
+      def respond_to_missing?(method, include_private = false)
+        @delegate.respond_to?(method) || super
+      end
+
       # Perform all enqueued tasks.
       #
       # This method must be called from within the executor. It must not be
@@ -383,6 +390,13 @@ def method_missing(method, *args, &block)
         ivar.wait
         ivar
       end
+
+      # Check whether the method is responsive
+      #
+      # @param [Symbol] method the method being called
+      def respond_to_missing?(method, include_private = false)
+        @delegate.respond_to?(method) || super
+      end
     end
     private_constant :AwaitDelegator
 

spec/concurrent/async_spec.rb

@@ -158,6 +158,11 @@ def many(*args, &block) nil; end
         }.to raise_error(StandardError)
       end
 
+      it 'returns the existence of the method' do
+        expect(subject.async.respond_to?(:echo)).to be_truthy
+        expect(subject.async.respond_to?(:not_exist_method)).to be_falsy
+      end
+
       it 'returns a :pending IVar' do
         val = subject.async.wait(1)
         expect(val).to be_a Concurrent::IVar
@@ -224,6 +229,11 @@ def many(*args, &block) nil; end
         }.to raise_error(StandardError)
       end
 
+      it 'returns the existence of the method' do
+        expect(subject.await.respond_to?(:echo)).to be_truthy
+        expect(subject.await.respond_to?(:not_exist_method)).to be_falsy
+      end
+
       it 'returns a :fulfilled IVar' do
         val = subject.await.echo(5)
         expect(val).to be_a Concurrent::IVar