Fix visibily of project services

This refactor improves the exclusion of disabled project services
removing the service exceptions parameter.

We were not listing the disabled project services but we were able to
edit the individual service if we know the valid URL. This commit fixes
that discrepancy between index and show.

app/controllers/projects/settings/integrations_controller.rb

@@ -7,17 +7,8 @@ module Projects
       layout "project_settings"
 
       def show
-        @services = @project.find_or_initialize_services(exceptions: service_exceptions)
-      end
-
-      private
-
-      # Returns a list of services that should be hidden from the list
-      def service_exceptions
-        @project.disabled_services.dup
+        @services = @project.find_or_initialize_services
       end
     end
   end
 end
-
-Projects::Settings::IntegrationsController.prepend_if_ee('EE::Projects::Settings::IntegrationsController')

app/models/project.rb

@@ -1238,14 +1238,12 @@ class Project < ApplicationRecord
     update_column(:has_external_wiki, services.external_wikis.any?) if Gitlab::Database.read_write?
   end
 
-  def find_or_initialize_services(exceptions: [])
-    available_services_names = Service.available_services_names - exceptions
+  def find_or_initialize_services
+    available_services_names = Service.available_services_names - disabled_services
 
-    available_services = available_services_names.map do |service_name|
+    available_services_names.map do |service_name|
       find_or_initialize_service(service_name)
     end
-
-    available_services.compact
   end
 
   def disabled_services

ee/app/controllers/ee/projects/settings/integrations_controller.rb

-# frozen_string_literal: true
-
-module EE
-  module Projects
-    module Settings
-      module IntegrationsController
-        extend ::Gitlab::Utils::Override
-
-        private
-
-        override :service_exceptions
-        def service_exceptions
-          super << slack_service
-        end
-
-        def slack_service
-          if ::Gitlab::CurrentSettings.slack_app_enabled
-            'slack_slash_commands'
-          else
-            'gitlab_slack_application'
-          end
-        end
-      end
-    end
-  end
-end

ee/app/models/ee/project.rb

@@ -545,6 +545,7 @@ module EE
         [].tap do |services|
           services.push('jenkins', 'jenkins_deprecated') unless feature_available?(:jenkins_integration)
           services.push('github') unless feature_available?(:github_project_service_integration)
+          ::Gitlab::CurrentSettings.slack_app_enabled ? services.push('slack_slash_commands') : services.push('gitlab_slack_application')
         end
       end
     end

ee/spec/features/projects/settings/slack_application_spec.rb

@@ -16,6 +16,7 @@ describe 'Slack application' do
     create(:slack_integration, service: service)
 
     allow(Gitlab).to receive(:com?).and_return(true)
+    allow(Gitlab::CurrentSettings).to receive(:slack_app_enabled).and_return(true)
   end
 
   it 'I can edit slack integration' do