We have implemented some custom form control components with decorators as follows:
@Component({
selector: 'value-selector',
templateUrl: './selector.component.html',
styleUrls: ['./selector.component.scss'],
providers: [
{
provide: NG_VALUE_ACCESSOR,
useExisting: forwardRef(() => ValueSelectorComponent),
multi: true
}
]
})During the update of certain dependencies, particularly babel, we had to introduce the forwardRef. This caused our provider to change from:
useExisting: ValueSelectorComponent,useExisting: forwardRef(() => ValueSelectorComponent),The JEST spec tests are set up to create a new instance using an instantiate method that is executed in the beforeEach block:
function instantiate({
eventTypeService = {},
translationService = {}
}): ValueSelectorComponent {
return new ValueSelectorComponent(
eventTypeService as EventTypeService,
translationService as TranslateService
);
}
describe(ValueSelectorComponent.name, () => {
let component: ValueSelectorComponent;
// abbreviated for clarity
beforeEach(() => {
mockTranslateGet = jest.fn().mockReturnValue(of());
mockTranslationService = {
get: mockTranslateGet
} as unknown as TranslateService;
getAllSpy = jest.fn();
mockEventTypeService = {
getAll: getAllSpy
} as unknown as EventTypeService;
// abbreviated for clarity
component = instantiate({
eventTypeService: mockEventTypeService,
translationService: mockTranslationService
});
});However, I am facing challenges in achieving code coverage for () and ValueSelectorComponent within the useExisting. Our test suite uses JEST, and all solutions discovered so far involve TestBed, which we do not utilize. Is there a way to ensure coverage for that particular line?