Add unit tests for services

**Feature request**
It would be great to have search for controllers.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_search` with default `false`.

Start by locating the controller and service implementations and the existing configuration handling. Determine how the enable_search option should be read, then define tests for controller search behavior and verify that the default remains false.

Written by the indexing model from the issue text.