We're implementing `super` in Firefox, and ran across this surprising behavior:
class X {
constructor() {
Object.defineProperty(this, "prop", {
configurable: true,
writable: false,
value: 1});
}
f() {
super.prop = 2; // overwrites non-writable property!
}
}
var x = new X();
x.f();
assertEq(x.prop, 2); // passes
In the spec, 9.1.9 step 4.d.i. is where `super.prop = 2` ends up, with
O=X.prototype.
Options:
1. Do nothing. Allow overwriting. It's a little weird, but this code
is pretty weird.
2. (post-ES6 of course) Add more "code" in 4.d.i. to perform a
[[GetOwnProperty]] and check.
-j
_______________________________________________
es-discuss mailing list
[email protected]
https://mail.mozilla.org/listinfo/es-discuss
