Abstract class constructor type issue

I tried using the injectable decorator with an abstract class but it gave me this error

Argument of type 'typeof MyClass' is not assignable to parameter of type 'constructor<{}>'.
      Cannot assign an abstract constructor type to a non-abstract constructor type.

Sample code

import { injectable } from "tsyringe";

@injectable()
abstract class MyClass {

}

I modified the declaration just to test (based on https://stackoverflow.com/questions/36886082/abstract-constructor-type-in-typescript)

type abstract_ctor<T> = Function & { prototype: T };
export declare function injectable<T>(): (target: constructor<T>|abstract_ctor<T>) => void;

and the compilation worked without errors

I will try cloning and running some tests to see if DI works fine with an abstract class

[unlocomqx]

Thank you for the hint, I didn’t think it would work without the base class decorator (coming from inversify) Your example works, but the following doesn’t

test("abstract class autoinjectable", () => {
  class Foo {}
  abstract class MyBase {
    constructor(public foo: Foo){}
  }

  @injectable()
  class MyClass extends MyBase {
  }

  const instance: MyClass = globalContainer.resolve(MyClass);
  expect(instance.foo instanceof Foo).toBeTruthy();
});

Do you think it can be implemented? Is the concept correct at least?

If not I can just duplicate the constructor in my child classes

Thank you

[unlocomqx]

I tried registering the abstract class using @autoInjectable in my PR #21 which worked fine except for a type error on return class extends target because I changed the constructor type. Error message: Type constructor<any> is not a constructor function type https://travis-ci.org/Microsoft/tsyringe/jobs/477314771

I didn’t find another way since the base constructor must be altered

But anyway, the base class seems to be present in the metadata So we may take the base constructor params, instantiate them and assign them as props of the derived class, I don’t know if it can be done or if it’s a clean solution