TS2377 reported for constructors that unconditionally throw or use return override

TypeScript Version:

3.7.0-dev.2019-10-10

Search Terms:

• TS2377
• TS 2377
• TS2377 throw
• TS 2377 throw

Code

Code like this is also generated by webidl2js:

class Foo extends Object {
	constructor () {
		throw new TypeError("Illegal constructor");
	}
}

Same with

class Foo extends Object {
	constructor () {
		return Object.create(new.target.prototype);
	}
}

Expected behavior:

No error

Actual behavior:

error TS2377: Constructors for derived classes must contain a 'super' call.

2     constructor() {
      ~~~~~~~~~~~~~~~
3         throw new TypeError();
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4     }
  ~~~~~

and

error TS2377: Constructors for derived classes must contain a 'super' call.

2     constructor() {
      ~~~~~~~~~~~~~~~
3         return Object.create(new.target.prototype);
  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
4     }
  ~~~~~

Playground Link:

🔗

Related Issues:

• #3696

Start with the two constructor examples and the linked Playground to reproduce TS2377, then read the related issue #3696 for context. The fix is complete when derived constructors that unconditionally throw or return an override no longer report TS2377, while the existing diagnostic remains for constructors that still require a super call.