To align with the updated style guide, Angular v20 will generate components
without a `.component` file extension type for all component related
files by default. Projects will automatically use this naming convention.
Projects can however opt-out by setting the `type` option to `Component`
for the component schematic. This can be done as a default in the `angular.json`
or directly on the commandline via `--type=Component` when executing `ng generate`.
As an example, `app.component.css` will now be named `app.css`. Additionally,
the TypeScript class name will be `App` instead of the previous `AppComponent`.
To align with the updated style guide, Angular v20 will generate
component templates with a `.ng.html` file extension instead of
the previous `.html` by default. Projects will automatically
use this new template extension. Projects can however opt-out of
component generation using `.ng.html` by setting the `ngHtml`
option to false for the component schematic. This can be done as
a default in the `angular.json` or directly on the commandline
via `--no-ng-html` when executing `ng generate`.
The defer block support introduces a new asynchronous form of the set class metadata Angular function. This form
is needed to allow for providing metadata for dynamically imported deferred components. The asynchronous compileComponents
call within TestBed is now used to initialize this metadata during unit tests. Unit tests that contain defer blocks
must use this call prior to executing a test to allow templates containing defer to properly render. Existing tests that
do not use the new defer block do not require modification unless the defer block is introduced into components used in
the unit test.
`compileComponents` is not necessary when using the CLI (as the templates are inlined) and just adds boilerplate code. So we can remove it from the test schematic and make it independent from `async/await` (only place we would have it in the CLI generated code, and in most Angular apps).
