[Performance] Optimize queries in conversation/message finders (#364)

* [Performance] Optimize queries in conversation/message finders

* Add message_finder spec

* Fix message_finder spec

.gitignore

@@ -43,3 +43,5 @@ public/packs*
 # coverage report
 buildreports
 coverage
+
+/storage

app/finders/conversation_finder.rb

@@ -66,7 +66,9 @@ class ConversationFinder
   end
 
   def find_all_conversations
-    @conversations = current_account.conversations.where(inbox_id: @inbox_ids)
+    @conversations = current_account.conversations.includes(
+      :assignee, :contact, :inbox
+    ).where(inbox_id: @inbox_ids)
   end
 
   def filter_by_assignee_type

app/finders/message_finder.rb

@@ -10,10 +10,14 @@ class MessageFinder
 
   private
 
-  def messages
-    return @conversation.messages if @params[:filter_internal_messages].blank?
+  def conversation_messages
+    @conversation.messages.includes(:attachment, user: { avatar_attachment: :blob })
+  end
 
-    @conversation.messages.where.not('private = ? OR message_type = ?', true, 2)
+  def messages
+    return conversation_messages if @params[:filter_internal_messages].blank?
+
+    conversation_messages.where.not('private = ? OR message_type = ?', true, 2)
   end
 
   def current_messages

app/views/api/v1/conversations/index.json.jbuilder

@@ -23,7 +23,7 @@ json.data do
       else
         json.messages conversation.unread_messages.map(&:push_event_data)
       end
-      json.inbox_id conversation.inbox.id
+      json.inbox_id conversation.inbox_id
       json.status conversation.status_before_type_cast
       json.timestamp conversation.messages.last.try(:created_at).try(:to_i)
       json.user_last_seen_at conversation.user_last_seen_at.to_i

spec/finders/message_finder_spec.rb

@@ -0,0 +1,47 @@
+require 'rails_helper'
+
+describe ::MessageFinder do
+  subject(:message_finder) { described_class.new(conversation, params) }
+
+  let!(:account) { create(:account) }
+  let!(:user) { create(:user, account: account) }
+  let!(:inbox) { create(:inbox, account: account) }
+  let!(:conversation) { create(:complete_conversation, account: account, inbox: inbox, assignee: user) }
+
+  before do
+    create(:message, account: account, inbox: inbox, conversation: conversation)
+    create(:message, message_type: 'activity', account: account, inbox: inbox, conversation: conversation)
+    create(:message, message_type: 'activity', account: account, inbox: inbox, conversation: conversation)
+    create(:message, message_type: 'outgoing', account: account, inbox: inbox, conversation: conversation)
+  end
+
+  describe '#perform' do
+    context 'with filter_internal_messages false' do
+      let(:params) { { filter_internal_messages: false } }
+
+      it 'filter conversations by status' do
+        result = message_finder.perform
+        expect(result.count).to be 4
+      end
+    end
+
+    context 'with filter_internal_messages true' do
+      let(:params) { { filter_internal_messages: true } }
+
+      it 'filter conversations by status' do
+        result = message_finder.perform
+        expect(result.count).to be 2
+      end
+    end
+
+    context 'with before attribute' do
+      let!(:outgoing) { create(:message, message_type: 'outgoing', account: account, inbox: inbox, conversation: conversation) }
+      let(:params) { { before: outgoing.id } }
+
+      it 'filter conversations by status' do
+        result = message_finder.perform
+        expect(result.count).to be 4
+      end
+    end
+  end
+end