Add unit tests for components

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

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

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

No file, test, or entry point is named in the issue. Start by locating the controller configuration and existing component unit tests, then determine where enable_caching belongs; done means the option defaults to false and controller caching behavior is covered by tests.

Written by the indexing model from the issue text.