Looking forward to see type guard support in language-service as well!

My simple use case:

interface Animal {
  type: 'fish' | 'bird';
}

interface Fish extends Animal {
  type: 'fish';
  foo: string;
}

interface Bird extends Animal {
  type: 'bird';
  bar: string;
}

@Component({})
class MyComponent {
  animal: Animal;

  isFish(animal: Animal): animal is Fish {
    return animal.type === 'fish';
  }

  isBird(animal: Animal): animal is Bird {
    return animal.type === 'bird';
  }
}

Use case 1

<app-fish *ngIf="isFish(animal)" [foo]="animal.foo"></app-fish>
<app-bird *ngIf="isBird(animal)" [bar]="animal.bar"></app-bird>

Use case 2

<ng-container [ngSwitch]="true">
  <app-fish *ngSwitchCase="isFish(animal)"></app-fish>
  <app-bird *ngSwitchCase="isBird(animal)"></app-bird>
</ng-container>

Are both use cases covered?

This would be a great addition, having an issue similar to case 2 that @dirkluijk posted.

@chuckjaz any updates? Anyone working on this? Thanks

Will this be solved in Ivy?

No, this isn't solved by Ivy, if anything, Ivy will cause more people to realize how badly they need ngSwitch to support type narrowing.

This would really clean up a lot of template code. How come this is such a low priority?