RESOLVED FIXED 170549
Cannot Object.seal() or Object.freeze() global "this"
https://bugs.webkit.org/show_bug.cgi?id=170549
Summary Cannot Object.seal() or Object.freeze() global "this"
Michael Saboff
Reported 2017-04-06 08:43:39 PDT
The ECMAScript standard describes a isExtensible method for Proxy objects that forwards on to the wrapped object. See <https://tc39.github.io/ecma262/#sec-proxy-object-internal-methods-and-internal-slots-isextensible>. We don’t have that method in JavaScriptCore. <rdar://problem/31478302>
Attachments
Patch (6.27 KB, patch)
2017-04-06 13:43 PDT, Michael Saboff
mark.lam: review+
Saam Barati
Comment 1 2017-04-06 08:48:53 PDT
(In reply to Michael Saboff from comment #0) > The ECMAScript standard describes a isExtensible method for Proxy objects > that forwards on to the wrapped object. See > <https://tc39.github.io/ecma262/#sec-proxy-object-internal-methods-and- > internal-slots-isextensible>. We don’t have that method in JavaScriptCore. > > <rdar://problem/31478302> The spec you linked to is for ProxyObject, not JSProxy. Perhaps the JSProxy info is in the HTML spec?
Michael Saboff
Comment 2 2017-04-06 09:12:16 PDT
(In reply to Saam Barati from comment #1) > (In reply to Michael Saboff from comment #0) > > The ECMAScript standard describes a isExtensible method for Proxy objects > > that forwards on to the wrapped object. See > > <https://tc39.github.io/ecma262/#sec-proxy-object-internal-methods-and- > > internal-slots-isextensible>. We don’t have that method in JavaScriptCore. > > > > <rdar://problem/31478302> > > The spec you linked to is for ProxyObject, not JSProxy. Perhaps the JSProxy > info is in the HTML spec? I should have been more specific. This is needed for the global "this" as it is a JSProxy to the global object. JSProxy doesn't implement isExtensible, but ProxyObject does.
Michael Saboff
Comment 3 2017-04-06 13:31:02 PDT
Changing the bug title to the symptom of the problem instead the cause. Doing this since it appears the fix requires changes to other code besides JSProxy.
Michael Saboff
Comment 4 2017-04-06 13:43:01 PDT
Michael Saboff
Comment 5 2017-04-06 13:56:49 PDT
Comment on attachment 306423 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=306423&action=review > Source/JavaScriptCore/interpreter/Interpreter.cpp:1162 > + return checkedReturn(throwTypeError(callFrame, throwScope, ASCIILiteral(ReadonlyPropertyWriteError))); A better error message is NonExtensibleObjectPropertyDefineError. I made that change locally.
Mark Lam
Comment 6 2017-04-06 13:57:17 PDT
Comment on attachment 306423 [details] Patch r=me
Michael Saboff
Comment 7 2017-04-06 17:17:48 PDT
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