Merge pull request #35021 from palkan/refactor/broadcasting-for-testing

Action Cable: move channel_name to Channel.broadcasting_for

6 files changed, 55 insertions, 19 deletions

diff --git a/actioncable/CHANGELOG.md b/actioncable/CHANGELOG.md
index 4109dd6138..7f3177b64e 100644
--- a/actioncable/CHANGELOG.md
+++ b/actioncable/CHANGELOG.md
@@ -1,3 +1,22 @@
+*   Add `Channel::Base#broadcast_to`.
+
+    You can now call `broadcast_to` within a channel action, which equals to
+    the `self.class.broadcast_to`.
+
+    *Vladimir Dementyev*
+
+*   Make `Channel::Base.broadcasting_for` a public API.
+
+    You can use `.broadcasting_for` to generate a unique stream identifier within
+    a channel for the specified target (e.g. Active Record model):
+
+    ```ruby
+    ChatChannel.broadcasting_for(model) # => "chat:<model.to_gid_param>"
+    ```
+
+    *Vladimir Dementyev*
+
+
 ## Rails 6.0.0.beta1 (January 18, 2019) ##
 
 *   Merge [`action-cable-testing`](https://github.com/palkan/action-cable-testing) to Rails.
diff --git a/actioncable/lib/action_cable/channel/broadcasting.rb b/actioncable/lib/action_cable/channel/broadcasting.rb
index 9a96720f4a..9f702e425e 100644
--- a/actioncable/lib/action_cable/channel/broadcasting.rb
+++ b/actioncable/lib/action_cable/channel/broadcasting.rb
@@ -7,22 +7,32 @@ module ActionCable
     module Broadcasting
       extend ActiveSupport::Concern
 
-      delegate :broadcasting_for, to: :class
+      delegate :broadcasting_for, :broadcast_to, to: :class
 
       module ClassMethods
         # Broadcast a hash to a unique broadcasting for this <tt>model</tt> in this channel.
         def broadcast_to(model, message)
-          ActionCable.server.broadcast(broadcasting_for([ channel_name, model ]), message)
+          ActionCable.server.broadcast(broadcasting_for(model), message)
         end
 
-        def broadcasting_for(model) #:nodoc:
+        # Returns a unique broadcasting identifier for this <tt>model</tt> in this channel:
+        #
+        #    CommentsChannel.broadcasting_for("all") # => "comments:all"
+        #
+        # You can pass any object as a target (e.g. Active Record model), and it
+        # would be serialized into a string under the hood.
+        def broadcasting_for(model)
+          serialize_broadcasting([ channel_name, model ])
+        end
+
+        def serialize_broadcasting(object) #:nodoc:
           case
-          when model.is_a?(Array)
-            model.map { |m| broadcasting_for(m) }.join(":")
-          when model.respond_to?(:to_gid_param)
-            model.to_gid_param
+          when object.is_a?(Array)
+            object.map { |m| serialize_broadcasting(m) }.join(":")
+          when object.respond_to?(:to_gid_param)
+            object.to_gid_param
           else
-            model.to_param
+            object.to_param
           end
         end
       end
diff --git a/actioncable/lib/action_cable/channel/streams.rb b/actioncable/lib/action_cable/channel/streams.rb
index 81c2c38064..7e1ed3c850 100644
--- a/actioncable/lib/action_cable/channel/streams.rb
+++ b/actioncable/lib/action_cable/channel/streams.rb
@@ -99,7 +99,7 @@ module ActionCable
       # Pass <tt>coder: ActiveSupport::JSON</tt> to decode messages as JSON before passing to the callback.
       # Defaults to <tt>coder: nil</tt> which does no decoding, passes raw messages.
       def stream_for(model, callback = nil, coder: nil, &block)
-        stream_from(broadcasting_for([ channel_name, model ]), callback || block, coder: coder)
+        stream_from(broadcasting_for(model), callback || block, coder: coder)
       end
 
       # Unsubscribes all streams associated with this channel from the pubsub queue.
diff --git a/actioncable/lib/action_cable/channel/test_case.rb b/actioncable/lib/action_cable/channel/test_case.rb
index c4cf0ac0e7..b05d51a61a 100644
--- a/actioncable/lib/action_cable/channel/test_case.rb
+++ b/actioncable/lib/action_cable/channel/test_case.rb
@@ -143,7 +143,7 @@ module ActionCable
     # You need to set up your connection manually to provide values for the identifiers.
     # To do this just use:
     #
-    #   stub_connection(user: users[:john])
+    #   stub_connection(user: users(:john))
     #
     # == Testing broadcasting
     #
@@ -157,9 +157,9 @@ module ActionCable
     #  end
     #
     #  def test_speak
-    #    subscribe room_id: rooms[:chat].id
+    #    subscribe room_id: rooms(:chat).id
     #
-    #    assert_broadcasts_on(rooms[:chat], text: "Hello, Rails!") do
+    #    assert_broadcasts_on(rooms(:chat), text: "Hello, Rails!") do
     #      perform :speak, message: "Hello, Rails!"
     #    end
     #  end
@@ -300,9 +300,7 @@ module ActionCable
           def broadcasting_for(stream_or_object)
             return stream_or_object if stream_or_object.is_a?(String)
 
-            self.class.channel_class.broadcasting_for(
-              [self.class.channel_class.channel_name, stream_or_object]
-            )
+            self.class.channel_class.broadcasting_for(stream_or_object)
           end
       end
 
diff --git a/actioncable/test/channel/broadcasting_test.rb b/actioncable/test/channel/broadcasting_test.rb
index 2cbfabc1d0..fb501a1bc2 100644
--- a/actioncable/test/channel/broadcasting_test.rb
+++ b/actioncable/test/channel/broadcasting_test.rb
@@ -26,14 +26,23 @@ class ActionCable::Channel::BroadcastingTest < ActionCable::TestCase
   end
 
   test "broadcasting_for with an object" do
-    assert_equal "Room#1-Campfire", ChatChannel.broadcasting_for(Room.new(1))
+    assert_equal(
+      "action_cable:channel:broadcasting_test:chat:Room#1-Campfire",
+      ChatChannel.broadcasting_for(Room.new(1))
+    )
   end
 
   test "broadcasting_for with an array" do
-    assert_equal "Room#1-Campfire:Room#2-Campfire", ChatChannel.broadcasting_for([ Room.new(1), Room.new(2) ])
+    assert_equal(
+      "action_cable:channel:broadcasting_test:chat:Room#1-Campfire:Room#2-Campfire",
+      ChatChannel.broadcasting_for([ Room.new(1), Room.new(2) ])
+    )
   end
 
   test "broadcasting_for with a string" do
-    assert_equal "hello", ChatChannel.broadcasting_for("hello")
+    assert_equal(
+      "action_cable:channel:broadcasting_test:chat:hello",
+      ChatChannel.broadcasting_for("hello")
+    )
   end
 end
diff --git a/actioncable/test/channel/test_case_test.rb b/actioncable/test/channel/test_case_test.rb
index 9c360d5dc3..a166c41e11 100644
--- a/actioncable/test/channel/test_case_test.rb
+++ b/actioncable/test/channel/test_case_test.rb
@@ -180,7 +180,7 @@ class BroadcastsTestChannel < ActionCable::Channel::Base
   def broadcast_to_user(data)
     user = User.new user_id
 
-    self.class.broadcast_to user, text: data["message"]
+    broadcast_to user, text: data["message"]
   end
 end