strictPropertyInitialization should consider return

[ghost]

TypeScript Version: 3.2.0-dev.20181004

Code

class C {
    x: number;

    constructor(b: boolean) {
        if (b) {
            this.x = 3;
        } else {
            return new C(true);
        }
    }
}

Expected behavior:

No error.

Actual behavior:

src/a.ts:2:5 - error TS2564: Property 'x' has no initializer and is not definitely assigned in the constructor.

2     x: number;

[RyanCavanaugh]

We have no way to distinguish this correct code from the incorrect version that calls new C(false);

[ghost]

That would be an infinite recursion, which we normally allow and doesn't seem related to --strictPropertyInitialization.

[AlCalzone]

I have another case of this. I want to enforce that whenever a class instance is created, the correct sub class constructor is used. A simplified repro would be the following:

class Foo {
  constructor() {
    if (new.target !== Sub) return new Sub();
    this.version = 1;
  }

  public version: number;
  // Error: Property 'version' has no initializer and is not definitely assigned in the constructor.
}

class Sub extends Foo { } // default constructor has the same issue as any constructor which calls super

console.log(new Foo().version); // prints 1
console.log(new Sub().version); // prints 1

As you can see, version is always defined, but TypeScript doesn't think so.