Which @angular/* package(s) are the source of the bug?

core

Is this a regression?

No

Description

If we use the inject function with a generic class (or abstract class), the return type won't be properly inferred:

import { inject } from '@angular/core';

class C<T extends number> {}

const c1 = inject(C); // type: C<any>
const c2 = inject(C<1>) // type: C<any>

abstract class AC<T extends string> {}

const ac1 = inject(AC); // type: AC<any>
const ac2 = inject(AC<'ng'>); // type: AC<any>

Typing issue is due to the AbstractType interface. It's currently defined as follows:

interface AbstractType<T> extends Function {
  prototype: T;
}

To solve this typing bug, AbstractType can be defined as follows:

type AbstractType<T> = abstract new (...args: unknown[]) => T;

Here is the Stackblitz playground containing the typedInject function that solves this issue.

This fix would introduce a breaking change.

If accepted, I'll create a PR for this bug.

Please provide a link to a minimal reproduction of the bug

https://stackblitz.com/edit/angular-qldklj?file=src%2Fapp%2Finject-typing-demo.ts

Please provide the exception or error you saw

No response

Please provide the environment you discovered this bug in (run ng version)

Angular CLI: 15.0.0

Anything else?

As a workaround, we can explicitly set the return type:

class C<T extends number> {}

const c = inject<C<number>>(C);