Error when constraining a mixin input class to an interface-CodePudding

I'm trying to make a mixin to give some classes an interface constraint, so that I know that the input class has certain properties.

Here's what I have at the moment.

  name: string;
  description: () => string;
}

function mixin<TBase extends Interface>(base: new(...args: any[]) => TBase) {
  return class Mixin extends base {
    get summary() {
      return `${this.name} ${this.description()}`;
    }
  }
}

The error I'm getting is at class Mixin inside the function, and the error is

  'Mixin' is assignable to the constraint of type 'TBase', but 'TBase' could be instantiated with a different subtype of constraint 'Interface'.ts(2415)

How do I get around this error?

CodePudding user response：

You can try

interface Interface{
   name: string;
  description: () => string;
}
type GConstructor<T extends Interface> = new (...args: any[]) => T;

function mixin<TBase extends GConstructor<Interface>>(base: TBase) {
  return class Mixin extends base {
    get summary() {
      return `${this.name} ${this.description()}`;
    }
  }
}