Internal method invariants vague about exceptions

[annevk]

A number of internal methods can throw per HTML, but https://tc39.github.io/ecma262/#sec-invariants-of-the-essential-internal-methods is not clear on whether that is allowed. (Despite it already being implicitly allowed, e.g., OrdinaryDelete invoking [[GetOwnProperty]] with a ? in front of it.)

This came up in whatwg/html#1726 as cross-origin [[Delete]] always throws in implementations, even outside "strict mode", and therefore cannot simply return false.

[claudepache]

All internal methods may throw: that can happen notably, but not exclusively, when user-defined code is triggered and throws (Proxies, user-defined accessors, etc.). And https://tc39.github.io/ecma262/#sec-invariants-of-the-essential-internal-methods applies only when the internal method returns nonabruptly: maybe that should be said explicitly?

[claudepache]

All internal methods may throw: that can happen notably, but not exclusively, when user-defined code is triggered and throws (Proxies, user-defined accessors, etc.). And https://tc39.github.io/ecma262/#sec-invariants-of-the-essential-internal-methods applies only when the internal method returns nonabruptly: maybe that should be said explicitly?

[annevk]

It would help me, I think I got myself confused a few times now reading that section.

[annevk]

It would help me, I think I got myself confused a few times now reading that section.