Bug 188952

Summary: output of toString() of Generator is wrong
Product: WebKit Reporter: sunlili
Component: JavaScriptCoreAssignee: Yusuke Suzuki <ysuzuki>
Status: RESOLVED FIXED    
Severity: Normal CC: ews-watchlist, fpizlo, keith_miller, mark.lam, msaboff, saam, webkit-bug-importer, ysuzuki
Priority: P2 Keywords: InRadar
Version: WebKit Local Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
Patch saam: review+

Description sunlili 2018-08-26 00:30:00 PDT
Executing following code :
--------------------------------------
var f = function* () {}
print(f.toString());
--------------------------------------

Output of JavaScriptCore is :
function () {}

However, the output should be :
function* () {}

BT group
2018.08.26
Comment 1 Yusuke Suzuki 2018-08-30 11:09:56 PDT
Created attachment 348511 [details]
Patch
Comment 2 Saam Barati 2018-08-30 11:12:02 PDT
Comment on attachment 348511 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=348511&action=review

r=me

> Source/JavaScriptCore/runtime/FunctionPrototype.cpp:136
> +        case SourceParseMode::AsyncGeneratorWrapperMethodMode:

Shouldn't this async generator method be "async* " since that's the syntax?
Comment 3 Yusuke Suzuki 2018-08-30 12:04:13 PDT
Comment on attachment 348511 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=348511&action=review

Thanks!

>> Source/JavaScriptCore/runtime/FunctionPrototype.cpp:136
>> +        case SourceParseMode::AsyncGeneratorWrapperMethodMode:
> 
> Shouldn't this async generator method be "async* " since that's the syntax?

Right now, we always emit `async function* ...` even for async generator methods, as we emit `function xxx() { }` for methods.
When https://tc39.github.io/Function-prototype-toString-revision/ is integrated into JSC, we should revisit these cases.
Comment 4 Yusuke Suzuki 2018-08-30 12:06:27 PDT
Landed in https://trac.webkit.org/changeset/235514/webkit
Comment 5 Radar WebKit Bug Importer 2018-08-31 08:56:34 PDT
<rdar://problem/43941925>