Bug 154745 – Add Proxy tests for exceptions that depend on an object being non-extensible and having configurable properties

• Status: NEW
• Component: JavaScriptCore

[Saam Barati]

I missed writing some of these tests because I didn't realize you could easily
make an object get into this state. But it's super easy. Object.preventExtensions
puts an object into this state.

[Filip Pizlo]

This is referenced from this commit: http://trac.webkit.org/changeset/197539.

That suggests that maybe that commit should have referenced a different bug?

[Saam Barati]

(In reply to comment #1)
> This is referenced from this commit: http://trac.webkit.org/changeset/197539.
> 
> That suggests that maybe that commit should have referenced a different bug?

Yeah it definitely should have. That was a mistake on my end.
Is it worth going back and editing the change log?

[Alexey Shvayka]

Test262 has complete coverage of internal methods invariants being validated by proxies, including non-extensible targets and non-configurable properties.
Just a few of them:
https://test262.report/browse/built-ins/Proxy/defineProperty/targetdesc-configurable-desc-not-configurable.js
https://test262.report/browse/built-ins/Proxy/defineProperty/targetdesc-undefined-target-is-not-extensible.js
https://test262.report/browse/built-ins/Proxy/set/target-property-is-not-configurable-not-writable-not-equal-to-v.js
https://test262.report/browse/built-ins/Proxy/set/return-true-target-property-is-not-configurable.js
https://test262.report/browse/built-ins/Proxy/isExtensible/return-is-different-from-target.js