Bug 223302 – [JSC] Implement Error#cause

• Component: New Bugs
• Status: RESOLVED FIXED

[Ross Kirsling]

[JSC] Implement Error#cause

[Ross Kirsling]

Created attachment 423427 [details]
Patch

[Ross Kirsling]

Comment on attachment 423427 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=423427&action=review

> Source/JavaScriptCore/API/JSObjectRef.cpp:236
>      JSValue message = argumentCount ? toJS(globalObject, arguments[0]) : jsUndefined();
> +    JSValue options = argumentCount > 1 ? toJS(globalObject, arguments[1]) : jsUndefined();
>      Structure* errorStructure = globalObject->errorStructure();
> -    JSObject* result = ErrorInstance::create(globalObject, errorStructure, message);
> +    JSObject* result = ErrorInstance::create(globalObject, errorStructure, message, options);

Note: We don't need to add support to JSObjectMakeError, but it's literally no extra effort to do so.

[Yusuke Suzuki]

Comment on attachment 423427 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=423427&action=review

r=me

> JSTests/stress/error-cause.js:6
> +const errorConstructors = [Error, EvalError, RangeError, ReferenceError, SyntaxError, TypeError, URIError, AggregateError];

Can we add WebAssembly Errors if `typeof WebAssembly !== "undefined"`?

[Ross Kirsling]

Created attachment 423430 [details]
Patch

[Ross Kirsling]

(In reply to Yusuke Suzuki from comment #3)
> > JSTests/stress/error-cause.js:6
> > +const errorConstructors = [Error, EvalError, RangeError, ReferenceError, SyntaxError, TypeError, URIError, AggregateError];
> 
> Can we add WebAssembly Errors if `typeof WebAssembly !== "undefined"`?

Oops, we actually don't want to test these; their behavior hasn't changed (since they're not part of ECMA-262), it's just that they depend on ErrorInstance, whose interface changed.

[EWS]

ChangeLog entry in JSTests/ChangeLog contains OOPS!.

[Ross Kirsling]

Created attachment 423435 [details]
Patch for landing

[EWS]

Committed r274552: <https://commits.webkit.org/r274552>

All reviewed patches have been landed. Closing bug and clearing flags on attachment 423435 [details].

[Radar WebKit Bug Importer]

<rdar://problem/75512624>

[Keith Miller]

Comment on attachment 423435 [details]
Patch for landing

This should probably be behind a JSC flag (it can be on by default though) since it's technically a feature, albeit a simple one.

[Devin Rousso]

Out of curiosity what does this look like in Web Inspector?  Should it have special treatment there given that one of the motivations for this feature was for developer tooling/debugging/etc.?

[Ross Kirsling]

(In reply to Keith Miller from comment #10)
> Comment on attachment 423435 [details]
> Patch for landing
> 
> This should probably be behind a JSC flag (it can be on by default though)
> since it's technically a feature, albeit a simple one.

Alright, I can add that to the WASM-related follow-up patch.

(In reply to Devin Rousso from comment #11)
> Out of curiosity what does this look like in Web Inspector?  Should it have
> special treatment there given that one of the motivations for this feature
> was for developer tooling/debugging/etc.?

It should look the same as before for now. It would make sense to have a helpful display for this information, though of course it's possible to use this information for non-debugging purposes too -- to give better error messages, to do different things based on the first error in the cascade, etc.