feat: Conversation API to return applied_sla and sla_events (#9174)

* chore: Add sla_events to push_event_data

* chore: Return SLA details in the API

* chore: feature lock sla push event data

* Update _conversation.json.jbuilder

* chore: rubocop fixes

spec/enterprise/controllers/api/v1/accounts/conversations_controller_spec.rb

@@ -0,0 +1,34 @@
+require 'rails_helper'
+
+RSpec.describe 'Conversations API', type: :request do
+  let(:account) { create(:account) }
+  let(:administrator) { create(:user, account: account, role: :administrator) }
+
+  describe 'GET /api/v1/accounts/{account.id}/conversations/:id' do
+    it 'returns SLA data for the conversation if the feature is enabled' do
+      account.enable_features!('sla')
+      conversation = create(:conversation, account: account)
+      applied_sla = create(:applied_sla, conversation: conversation)
+      sla_event = create(:sla_event, conversation: conversation, applied_sla: applied_sla)
+
+      get "/api/v1/accounts/#{account.id}/conversations/#{conversation.display_id}", headers: administrator.create_new_auth_token
+
+      expect(response).to have_http_status(:ok)
+      expect(response.parsed_body['applied_sla']['id']).to eq(applied_sla.id)
+      expect(response.parsed_body['sla_events'].first['id']).to eq(sla_event.id)
+    end
+
+    it 'does not return SLA data for the conversation if the feature is disabled' do
+      account.disable_features!('sla')
+      conversation = create(:conversation, account: account)
+      create(:applied_sla, conversation: conversation)
+      create(:sla_event, conversation: conversation)
+
+      get "/api/v1/accounts/#{account.id}/conversations/#{conversation.display_id}", headers: administrator.create_new_auth_token
+
+      expect(response).to have_http_status(:ok)
+      expect(response.parsed_body.keys).not_to include('applied_sla')
+      expect(response.parsed_body.keys).not_to include('sla_events')
+    end
+  end
+end