Bug: formatHtml on MockedComponentFixture / DebugElement won't give expected value

[andreandersson]

Description of the bug

When creating an Angular-component with MockRender, the actual component under testing becomes wrapped in another "dummy"-component. This creates a problem when you want to use ngMocks.formatHtml (and possibly formatText) to check if nothing is rendered within the component at all.

Our example is quite a bit bigger, but we listen to a service and render a template in a sidebar if there actually are anything emitted from the service. Now we want to test that logic, and formatHtml seems like it should be the correct way to do it.

An idea might be to check for isFixture here and somehow get the inner / actual component.

An example of the bug

Link: https://stackblitz.com/edit/github-lnydij?file=src%2Ftest.spec.ts

Expected vs actual behavior

Expected that ngMocks.formatHtml(MockRender(TargetComponent)) should return ''.

Actual is that ngMocks.formatHtml(MockRender(TargetComponent)) returns ''.

We can, in theory, test for the content to be ''. However, if you have any @input to the component it becomes difficult quite fast since the expectation might <app-target ng-reflect-text="TEST">TEST</app-target> instead. Also tried with fixture.debugElement but that seems to give the same result.