Creating even easier component tests with Angular CDK component harnesses

When writing tests for components, there might be scenarios where you'd actually want to interact with the DOM elements. Now, this can already be achieved by using the fixture.debugElement.query method to find the element using a selector and then triggering events on it. However, that means maintaining it for different platforms, knowing the identifiers of all the selectors, and then exposing all of that in the tests. And this is even worse if we're talking about an Angular library. It certainly isn't necessary for each developer who interacts with my library to know all the element selectors in order to write the tests. Only the author of the library should know that much to respect encapsulation. Luckily, we have the component harnesses from the Angular CDK team, which were released with Angular 9 along with the IVY compiler. And they've led by example, by providing component harnesses...