Add Action Cable test adapter

actioncable/lib/action_cable/subscription_adapter.rb

@@ -5,6 +5,7 @@ module SubscriptionAdapter
     extend ActiveSupport::Autoload
 
     autoload :Base
+    autoload :Test
     autoload :SubscriberMap
     autoload :ChannelPrefix
   end

actioncable/lib/action_cable/subscription_adapter/test.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+require_relative "async"
+
+module ActionCable
+  module SubscriptionAdapter
+    # == Test adapter for Action Cable
+    #
+    # The test adapter should be used only in testing. Along with
+    # <tt>ActionCable::TestHelper</tt> it makes a great tool to test your Rails application.
+    #
+    # To use the test adapter set adapter value to +test+ in your +cable.yml+.
+    #
+    # NOTE: Test adapter extends the <tt>ActionCable::SubscriptionsAdapter::Async</tt> adapter,
+    # so it could be used in system tests too.
+    class Test < Async
+      def broadcast(channel, payload)
+        broadcasts(channel) << payload
+        super
+      end
+
+      def broadcasts(channel)
+        channels_data[channel] ||= []
+      end
+
+      def clear_messages(channel)
+        channels_data[channel] = []
+      end
+
+      def clear
+        @channels_data = nil
+      end
+
+      private
+        def channels_data
+          @channels_data ||= {}
+        end
+    end
+  end
+end

actioncable/test/subscription_adapter/test_adapter_test.rb

@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require "test_helper"
+require_relative "common"
+
+class ActionCable::SubscriptionAdapter::TestTest < ActionCable::TestCase
+  include CommonSubscriptionAdapterTest
+
+  def setup
+    super
+
+    @tx_adapter.shutdown
+    @tx_adapter = @rx_adapter
+  end
+
+  def cable_config
+    { adapter: "test" }
+  end
+
+  test "#broadcast stores messages for streams" do
+    @tx_adapter.broadcast("channel", "payload")
+    @tx_adapter.broadcast("channel2", "payload2")
+
+    assert_equal ["payload"], @tx_adapter.broadcasts("channel")
+    assert_equal ["payload2"], @tx_adapter.broadcasts("channel2")
+  end
+
+  test "#clear_messages deletes recorded broadcasts for the channel" do
+    @tx_adapter.broadcast("channel", "payload")
+    @tx_adapter.broadcast("channel2", "payload2")
+
+    @tx_adapter.clear_messages("channel")
+
+    assert_equal [], @tx_adapter.broadcasts("channel")
+    assert_equal ["payload2"], @tx_adapter.broadcasts("channel2")
+  end
+
+  test "#clear deletes all recorded broadcasts" do
+    @tx_adapter.broadcast("channel", "payload")
+    @tx_adapter.broadcast("channel2", "payload2")
+
+    @tx_adapter.clear
+
+    assert_equal [], @tx_adapter.broadcasts("channel")
+    assert_equal [], @tx_adapter.broadcasts("channel2")
+  end
+end