DDC+-dev.3.0: '_Future' is not a subtype of ...

[matanlurey]

'_Future' is not a subtype of type 'Future<ComponentRef<TestWithNullComponent>>'

This is blocking DDC-dev.30, and Dart2.

Code:

https://github.com/dart-lang/angular/blob/f55fea736cb25040be640e75541acfbcd34e0329/angular/lib/src/core/linker/component_factory.dart#L62-L93

Notably, we can't just unsafeCast ComponentRef<dynamic>:

https://github.com/dart-lang/angular/blob/f55fea736cb25040be640e75541acfbcd34e0329/angular/lib/src/core/linker/component_factory.dart#L88-L91

... because it is an an AppView<dynamic>, not an AppView<T>.

This violates our contract. We have a couple of options:

• Always return a ComponentRef<dynamic>: We lose auto-complete/type-safety.
• Add a .cast<E> method to ComponentRef and use it = extra work per load.
• Try and get the _View{Name}Host to return <T> not <dynamic>.

The last one is the "right" thing to do, but likely not easy.

[matanlurey]

Oops, turns out we do type this correctly:

https://github.com/dart-lang/angular/blob/f55fea736cb25040be640e75541acfbcd34e0329/_goldens/test/_files/component_loader_pattern.template_release.golden#L52-L59

... or mostly, so there is something else going on.

[matanlurey]

OK, looks easier than expected to fix.

Looks like something related with type inference in DDC. I'll file a bug.

[matanlurey]

Nope, we just had a return type of dynamic instead of R. Fixing...