DEV: start/stop reply implementation (#29542)

* DEV: join/leave presence chat-reply when streaming

This commit ensures that starting/stopping a chat message with the streaming option will automatically make the creator of the message as present in the chat-reply channel.

* implements start/stop reply

* not needed

plugins/chat/spec/services/chat/start_reply_spec.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+RSpec.describe Chat::StartReply do
+  describe described_class::Contract, type: :model do
+    subject(:contract) { described_class.new }
+
+    it { is_expected.to validate_presence_of :channel_id }
+  end
+
+  describe ".call" do
+    subject(:result) { described_class.call(params:, **dependencies) }
+
+    fab!(:user)
+    fab!(:channel) { Fabricate(:chat_channel, threading_enabled: true) }
+    fab!(:thread) { Fabricate(:chat_thread, channel: channel) }
+
+    let(:guardian) { user.guardian }
+    let(:params) { { channel_id: channel.id, thread_id: thread.id } }
+    let(:dependencies) { { guardian: } }
+
+    before { channel.add(guardian.user) }
+
+    context "when the channel is not found" do
+      before { params[:channel_id] = 999 }
+
+      it { is_expected.to fail_to_find_a_model(:presence_channel) }
+    end
+
+    context "when the thread is not found" do
+      before { params[:thread_id] = 999 }
+
+      it { is_expected.to fail_to_find_a_model(:presence_channel) }
+    end
+
+    it "generates a client id" do
+      expect(result.client_id).to be_present
+    end
+
+    it "joins the presence channel" do
+      expect { result }.to change {
+        PresenceChannel.new("/chat-reply/#{channel.id}/thread/#{thread.id}").count
+      }.by(1)
+    end
+
+    context "when the user is not part of the channel" do
+      fab!(:channel) { Fabricate(:private_category_channel, threading_enabled: true) }
+
+      before { params[:thread_id] = nil }
+
+      it { is_expected.to fail_a_step(:join_chat_reply_presence_channel) }
+    end
+  end
+end

plugins/chat/spec/services/chat/stop_reply_spec.rb

@@ -0,0 +1,51 @@
+# frozen_string_literal: true
+
+RSpec.describe Chat::StopReply do
+  describe described_class::Contract, type: :model do
+    subject(:contract) { described_class.new }
+
+    it { is_expected.to validate_presence_of :channel_id }
+    it { is_expected.to validate_presence_of :client_id }
+  end
+
+  describe ".call" do
+    subject(:result) { described_class.call(params:, **dependencies) }
+
+    fab!(:user)
+    fab!(:channel) { Fabricate(:chat_channel, threading_enabled: true) }
+    fab!(:thread) { Fabricate(:chat_thread, channel: channel) }
+    fab!(:client_id) do
+      Chat::StartReply.call(
+        params: {
+          channel_id: channel.id,
+          thread_id: thread.id,
+        },
+        guardian: user.guardian,
+      ).client_id
+    end
+
+    let(:guardian) { user.guardian }
+    let(:params) { { client_id: client_id, channel_id: channel.id, thread_id: thread.id } }
+    let(:dependencies) { { guardian: } }
+
+    before { channel.add(guardian.user) }
+
+    context "when the channel is not found" do
+      before { params[:channel_id] = 999 }
+
+      it { is_expected.to fail_to_find_a_model(:presence_channel) }
+    end
+
+    context "when the thread is not found" do
+      before { params[:thread_id] = 999 }
+
+      it { is_expected.to fail_to_find_a_model(:presence_channel) }
+    end
+
+    it "leaves the presence channel" do
+      presence_channel = PresenceChannel.new("/chat-reply/#{channel.id}/thread/#{thread.id}")
+
+      expect { result }.to change { presence_channel.count }.by(-1)
+    end
+  end
+end