In View Engine, providers which neither used `useValue`, `useClass`,
`useFactory` or `useExisting`, were interpreted differently.
e.g.
```
{provide: X} -> {provide: X, useValue: undefined}, // this is how it works in View Engine
{provide: X} -> {provide: X, useClass: X}, // this is how it works in Ivy
```
The missing-injectable migration should migrate such providers to the
explicit `useValue` provider. This ensures that there is no unexpected
behavioral change when updating to v9.
PR Close#33709
We should not migrate the reference from `useExisting`. This is because
developers can only use the `useExisting` value as a token. e.g.
```ts
@NgModule({
providers: [
{provide: AppRippleConfig, useValue: rippleOptions},
{provide: MAT_RIPPLE_OPTIONS, useExisting: AppRippleConfig},
]
})
export class AppModule {}
```
In the case above, nothing should be decorated with `@Injectable`. The
`AppRippleConfig` class is just used as a token for injection.
PR Close#33286
Improves the `missing-injectable` migration test case in the
`ng_update_migrations` integration test by adding scenarios
for the recent changes that have been made to the migration.
e.g. 5557dec120
PR Close#33223
Adds a new test to the `ng_update_migrations` that ensures
that the `missing-injectable` migration works properly in a
real CLI project. Additionally this ensures that the
`missing-injectable` and `undecorated-classes-with-di` migrations
play nicely together.
PR Close#32349
Creates anew integratin test for `ng-update` migrations. The
integration test uses an Angular CLI project that will be updated
using the latest package output symlinked from then `./dist/packages-dist`.
This allows us to ensure that migrations work in real CLI projects.
Another big benefit is that the Angular version is updated to the
latest. This is something we couldn't replicate in unit tests but
is extremely important. It's important because compilation could
break with newer Angular versions (note that migrations are always
executed after the new angular version has been installed).
PR Close#32349
Paul Gschwendtner