Test coverage of the ApiVisualEditor class, which loads the editor via the API, is quite low. ApiVisualEditorTest currently covers just the static methods.
We should add a basic test to cover ApiVisualEditor::execute, the function that loads the editor. This is fairly straightforward if we update the the ApiVisualEditorTest class to extend ApiTestCase.
Doing this should make it easier to add more fine-tuned tests later.