DEV: Refactor UpdateUserLastRead a little

We’re now using `contract` as the first step and validations for
mandatory parameters have been added.

To simplify specs a bit, we only assert the service contract is run as
expected without testing each validation case. We’re now testing the
contract itself in isolation.

plugins/chat/app/services/update_user_last_read.rb

@@ -17,9 +17,9 @@ module Chat
       #   @param [Guardian] guardian
       #   @return [Chat::Service::Base::Context]
 
+      contract
       model :membership, :fetch_active_membership
       policy :invalid_access
-      contract
       policy :ensure_message_id_recency
       policy :ensure_message_exists
       step :update_last_read_message_id
@@ -31,6 +31,8 @@ module Chat
         attribute :message_id, :integer
         attribute :user_id, :integer
         attribute :channel_id, :integer
+
+        validates :message_id, :user_id, :channel_id, presence: true
       end
 
       private

plugins/chat/spec/services/update_user_last_read_spec.rb

@@ -1,6 +1,13 @@
 # frozen_string_literal: true
 
-RSpec.describe(Chat::Service::UpdateUserLastRead) do
+RSpec.describe Chat::Service::UpdateUserLastRead do
+  describe Chat::Service::UpdateUserLastRead::Contract, type: :model do
+    it { is_expected.to validate_presence_of :user_id }
+    it { is_expected.to validate_presence_of :channel_id }
+    it { is_expected.to validate_presence_of :message_id }
+  end
+
+  describe ".call" do
     subject(:result) { described_class.call(params) }
 
     fab!(:current_user) { Fabricate(:user) }
@@ -20,18 +27,13 @@ RSpec.describe(Chat::Service::UpdateUserLastRead) do
       }
     end
 
-  context "when channel_id is not provided" do
-    before { params.delete(:channel_id) }
-
-    it { is_expected.to fail_to_find_a_model(:membership) }
-  end
-
-  context "when user_id is not provided" do
+    context "when params are not valid" do
       before { params.delete(:user_id) }
 
-    it { is_expected.to fail_to_find_a_model(:membership) }
+      it { is_expected.to fail_a_contract }
     end
 
+    context "when params are valid" do
       context "when user has no membership" do
         before { membership.destroy! }
 
@@ -70,8 +72,25 @@ RSpec.describe(Chat::Service::UpdateUserLastRead) do
         it { is_expected.to fail_a_policy(:ensure_message_exists) }
       end
 
-  context "when params are valid" do
-    before { Jobs.run_immediately! }
+      context "when everything is fine" do
+        fab!(:notification) do
+          Fabricate(
+            :notification,
+            notification_type: Notification.types[:chat_mention],
+            user: current_user,
+          )
+        end
+
+        let(:messages) { MessageBus.track_publish { result } }
+
+        before do
+          Jobs.run_immediately!
+          ChatMention.create!(
+            notification: notification,
+            user: current_user,
+            chat_message: message_1,
+          )
+        end
 
         it "sets the service result as successful" do
           expect(result).to be_a_success
@@ -82,24 +101,6 @@ RSpec.describe(Chat::Service::UpdateUserLastRead) do
         end
 
         it "marks existing notifications related to the message as read" do
-      expect {
-        notification =
-          Fabricate(
-            :notification,
-            notification_type: Notification.types[:chat_mention],
-            user: current_user,
-          )
-
-        # FIXME: we need a better way to create proper chat mention
-        ChatMention.create!(notification: notification, user: current_user, chat_message: message_1)
-      }.to change {
-        Notification.where(
-          notification_type: Notification.types[:chat_mention],
-          user: current_user,
-          read: false,
-        ).count
-      }.by(1)
-
           expect { result }.to change {
             Notification.where(
               notification_type: Notification.types[:chat_mention],
@@ -110,9 +111,9 @@ RSpec.describe(Chat::Service::UpdateUserLastRead) do
         end
 
         it "publishes new last read to clients" do
-      messages = MessageBus.track_publish { result }
-
           expect(messages.map(&:channel)).to include("/chat/user-tracking-state/#{current_user.id}")
         end
       end
     end
+  end
+end