Bug 187724 - JSON.stringify should emit non own properties if second array argument includes
Summary: JSON.stringify should emit non own properties if second array argument includes
Alias: None
Product: WebKit
Classification: Unclassified
Component: JavaScriptCore (show other bugs)
Version: Safari 11
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Yusuke Suzuki
Keywords: InRadar
Depends on:
Reported: 2018-07-16 19:43 PDT by zac spitzer
Modified: 2018-07-19 09:26 PDT (History)
11 users (show)

See Also:

Patch (8.92 KB, patch)
2018-07-18 04:01 PDT, Yusuke Suzuki
no flags Details | Formatted Diff | Diff
Archive of layout-test-results from ews206 for win-future (13.11 MB, application/zip)
2018-07-18 05:37 PDT, EWS Watchlist
no flags Details

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Description zac spitzer 2018-07-16 19:43:52 PDT
The following test case produces an empty object in Webkit


Firefox, Edge and Chrome all output an object with three properties

function createSyntaxException() {
    try {
        // trigger a DOMException
    } catch(e) {
        // this produces an empty object in webkit
        var err = JSON.parse(
          JSON.stringify(e, ['code','name','message'] )
        var err2 = {
          code: e.code,
          name: e.name,
          message: e.message
throw createSyntaxException();
Comment 1 Radar WebKit Bug Importer 2018-07-17 16:56:03 PDT
Comment 2 Yusuke Suzuki 2018-07-17 17:22:14 PDT
It seems that WebKit behavior is correct, but I would like to hear opinions from binding folks. My understanding is the following.

According to DOMException's IDL, defined in WebIDL.


interface DOMException { // but see below note about ECMAScript binding
  readonly attribute DOMString name;
  readonly attribute DOMString message;
  readonly attribute unsigned short code;

  const unsigned short INDEX_SIZE_ERR = 1;

This definition says that "name", "message", and "code" are readonly attributes. So they should be defined as getters in DOMException.prototype.

From the point of view of JSC, this makes `JSON.stringify(error)` empty since "name", "message", and "code" are not own properties.
Comment 3 zac spitzer 2018-07-17 20:22:30 PDT
but I'm passing in an array of ['code','name','message'] as a replacer to stringify which should pluck those values out?
Comment 4 Yusuke Suzuki 2018-07-17 23:33:54 PDT
Ah, I missed the point. The second argument array forces us to emit properties even if it is not an own property.
Comment 5 Yusuke Suzuki 2018-07-18 04:01:28 PDT
Created attachment 345235 [details]
Comment 6 EWS Watchlist 2018-07-18 05:37:24 PDT
Comment on attachment 345235 [details]

Attachment 345235 [details] did not pass win-ews (win):
Output: https://webkit-queues.webkit.org/results/8573642

New failing tests:
Comment 7 EWS Watchlist 2018-07-18 05:37:37 PDT
Created attachment 345237 [details]
Archive of layout-test-results from ews206 for win-future

The attached test failures were seen while running run-webkit-tests on the win-ews.
Bot: ews206  Port: win-future  Platform: CYGWIN_NT-6.1-2.9.0-0.318-5-3-x86_64-64bit
Comment 8 Mark Lam 2018-07-18 11:42:05 PDT
Comment on attachment 345235 [details]

Comment 9 Yusuke Suzuki 2018-07-18 11:45:09 PDT
Comment on attachment 345235 [details]

Thank you!
Comment 10 WebKit Commit Bot 2018-07-18 12:01:41 PDT
Comment on attachment 345235 [details]

Clearing flags on attachment: 345235

Committed r233924: <https://trac.webkit.org/changeset/233924>
Comment 11 WebKit Commit Bot 2018-07-18 12:01:43 PDT
All reviewed patches have been landed.  Closing bug.