> > I think I'd rather see `Promise.resolve` changed to use `this.constructor` > instead of `this.[[PromiseConstructor]]`, like every other Promise-related > method. Can someone who feels strongly otherwise give me the use case for > `[[PromiseConstructor]]` existing? >
I'll give it a shot. "Promise.resolve", executed on a constructor C, with argument x, should only return x if x was created by C.[[Construct]]. Otherwise it should create an instance of C which is resolved with x. If we used "x.constructor" to determine the actual constructor, then someone could just change the "constructor" property for x and fool someone who wrote "C.resolve(x)" and expected to get an instance of C back. It would be an unreliable, unsound conversion function. Proper subclassing requires subclassing support from the engine.
_______________________________________________ es-discuss mailing list [email protected] https://mail.mozilla.org/listinfo/es-discuss
