DEV: Add specs to ChannelSerializer and StructuredChannelSerializer (#20872)

This adds specs to the mentioned serializers to catch regressions
with MessageBus last_ids and to ensure the correct ones are being
returned and passed down to the ChannelSerializer.

Followup to d8ad5c3

plugins/chat/app/serializers/chat/structured_channel_serializer.rb

@@ -58,11 +58,13 @@ module Chat
           chat_message_bus_last_ids[Chat::Publisher::CHANNEL_ARCHIVE_STATUS_MESSAGE_BUS_CHANNEL],
       }
 
-      if id =
-           chat_message_bus_last_ids[
-             Chat::Publisher.user_tracking_state_message_bus_channel(scope.user.id)
-           ]
-        last_ids[:user_tracking_state] = id
+      if !scope.anonymous?
+        user_tracking_state_last_id =
+          chat_message_bus_last_ids[
+            Chat::Publisher.user_tracking_state_message_bus_channel(scope.user.id)
+          ]
+
+        last_ids[:user_tracking_state] = user_tracking_state_last_id if user_tracking_state_last_id
       end
 
       { message_bus_last_ids: last_ids }

plugins/chat/spec/serializer/chat/channel_serializer_spec.rb

@@ -47,4 +47,70 @@ describe Chat::ChannelSerializer do
       end
     end
   end
+
+  describe "#meta" do
+    context "for category channels" do
+      fab!(:chat_channel) { Fabricate(:chat_channel) }
+
+      it "has the required message_bus_last_ids keys and calls MessageBus" do
+        MessageBus.expects(:last_id).with(Chat::Publisher.root_message_bus_channel(chat_channel.id))
+        MessageBus.expects(:last_id).with(
+          Chat::Publisher.new_messages_message_bus_channel(chat_channel.id),
+        )
+        MessageBus.expects(:last_id).with(
+          Chat::Publisher.new_mentions_message_bus_channel(chat_channel.id),
+        )
+        MessageBus.expects(:last_id).with(
+          Chat::Publisher.kick_users_message_bus_channel(chat_channel.id),
+        )
+        expect(subject.as_json.dig(:meta, :message_bus_last_ids).keys).to eq(
+          %i[channel_message_bus_last_id new_messages new_mentions kick],
+        )
+      end
+
+      it "gets the kick_message_bus_last_id" do
+        MessageBus.expects(:last_id).at_least_once
+        MessageBus.expects(:last_id).with(
+          Chat::Publisher.kick_users_message_bus_channel(chat_channel.id),
+        )
+        expect(subject.as_json[:meta][:message_bus_last_ids].key?(:kick)).to eq(true)
+      end
+
+      it "does not call MessageBus for last_id if all the last IDs are already passed in" do
+        MessageBus.expects(:last_id).never
+        described_class.new(
+          chat_channel,
+          scope: guardian,
+          root: nil,
+          channel_message_bus_last_id: 1,
+          new_messages_message_bus_last_id: 1,
+          new_mentions_message_bus_last_id: 1,
+          kick_message_bus_last_id: 1,
+        ).as_json
+      end
+    end
+
+    context "for direct message channels" do
+      fab!(:chat_channel) { Fabricate(:direct_message_channel) }
+
+      it "has the required message_bus_last_ids keys and calls MessageBus" do
+        MessageBus.expects(:last_id).with(Chat::Publisher.root_message_bus_channel(chat_channel.id))
+        MessageBus.expects(:last_id).with(
+          Chat::Publisher.new_messages_message_bus_channel(chat_channel.id),
+        )
+        MessageBus.expects(:last_id).with(
+          Chat::Publisher.new_mentions_message_bus_channel(chat_channel.id),
+        )
+        expect(subject.as_json.dig(:meta, :message_bus_last_ids).keys).to eq(
+          %i[channel_message_bus_last_id new_messages new_mentions],
+        )
+      end
+
+      it "does not get the kick_message_bus_last_id" do
+        MessageBus.expects(:last_id).at_least_once
+        MessageBus.expects(:last_id).never
+        expect(subject.as_json[:meta][:message_bus_last_ids].key?(:kick)).to eq(false)
+      end
+    end
+  end
 end

plugins/chat/spec/serializer/chat/structured_channel_serializer_spec.rb

@@ -104,4 +104,103 @@ RSpec.describe Chat::StructuredChannelSerializer do
       ],
     ).to eq(nil)
   end
+
+  describe "#meta" do
+    context "when user is anonymous" do
+      it "does not query MessageBus for the user_tracking_state_message_bus_channel last_id" do
+        Chat::Publisher.expects(:user_tracking_state_message_bus_channel).never
+        json = described_class.new(fetch_data, scope: Guardian.new).as_json
+        expect(
+          json.dig(:structured_channel, :meta, :message_bus_last_ids).key?(:user_tracking_state),
+        ).to eq(false)
+      end
+    end
+
+    context "when user is not anonymous" do
+      it "has the required message_bus_last_ids" do
+        expect(
+          described_class
+            .new(fetch_data, scope: guardian)
+            .as_json
+            .dig(:structured_channel, :meta, :message_bus_last_ids)
+            .keys,
+        ).to eq(
+          %i[
+            channel_metadata
+            channel_edits
+            channel_status
+            new_channel
+            archive_status
+            user_tracking_state
+          ],
+        )
+      end
+
+      it "calls MessageBus.last_ids with all the required channels for each public and DM chat chat channel" do
+        MessageBus
+          .expects(:last_ids)
+          .with(
+            Chat::Publisher::CHANNEL_METADATA_MESSAGE_BUS_CHANNEL,
+            Chat::Publisher::CHANNEL_EDITS_MESSAGE_BUS_CHANNEL,
+            Chat::Publisher::CHANNEL_STATUS_MESSAGE_BUS_CHANNEL,
+            Chat::Publisher::NEW_CHANNEL_MESSAGE_BUS_CHANNEL,
+            Chat::Publisher::CHANNEL_ARCHIVE_STATUS_MESSAGE_BUS_CHANNEL,
+            Chat::Publisher.user_tracking_state_message_bus_channel(user1.id),
+            Chat::Publisher.new_messages_message_bus_channel(channel1.id),
+            Chat::Publisher.new_mentions_message_bus_channel(channel1.id),
+            Chat::Publisher.kick_users_message_bus_channel(channel1.id),
+            Chat::Publisher.root_message_bus_channel(channel1.id),
+            Chat::Publisher.new_messages_message_bus_channel(channel2.id),
+            Chat::Publisher.new_mentions_message_bus_channel(channel2.id),
+            Chat::Publisher.kick_users_message_bus_channel(channel2.id),
+            Chat::Publisher.root_message_bus_channel(channel2.id),
+            Chat::Publisher.new_messages_message_bus_channel(channel3.id),
+            Chat::Publisher.new_mentions_message_bus_channel(channel3.id),
+            Chat::Publisher.root_message_bus_channel(channel3.id),
+            Chat::Publisher.new_messages_message_bus_channel(channel4.id),
+            Chat::Publisher.new_mentions_message_bus_channel(channel4.id),
+            Chat::Publisher.root_message_bus_channel(channel4.id),
+          )
+          .returns({})
+        described_class.new(fetch_data, scope: guardian).as_json
+      end
+
+      it "passes down the required message_bus ids for category channels to Chat::ChannelSerializer" do
+        data = fetch_data
+        Chat::ChannelSerializer.expects(:new).at_least_once
+        Chat::ChannelSerializer
+          .expects(:new)
+          .with(
+            channel1,
+            root: nil,
+            scope: guardian,
+            membership: membership1,
+            new_messages_message_bus_last_id: 0,
+            new_mentions_message_bus_last_id: 0,
+            kick_message_bus_last_id: 0,
+            channel_message_bus_last_id: 0,
+          )
+          .once
+        described_class.new(data, scope: guardian).as_json
+      end
+
+      it "passes down the required message_bus ids for direct message channels to Chat::ChannelSerializer" do
+        data = fetch_data
+        Chat::ChannelSerializer.expects(:new).at_least_once
+        Chat::ChannelSerializer
+          .expects(:new)
+          .with(
+            channel3,
+            root: nil,
+            scope: guardian,
+            membership: membership3,
+            new_messages_message_bus_last_id: 0,
+            new_mentions_message_bus_last_id: 0,
+            channel_message_bus_last_id: 0,
+          )
+          .once
+        described_class.new(data, scope: guardian).as_json
+      end
+    end
+  end
 end