Bug 158334 – Web Inspector: API View of Native DOM APIs looks poor (TypeErrors for native getters)

• Status: RESOLVED
• Resolution: FIXED
• Component: Web Inspector

[Joseph Pecoraro]

* SUMMARY
API View of Native DOM APIs looks poor (TypeErrors for native getters).

See attached screenshot.

* STEPS TO REPRODUCE
1. js> dir(document.body)
2. Expand Prototypes in Console
  => TypeErrors everywhere

[Radar WebKit Bug Importer]

<rdar://problem/26615366>

[Joseph Pecoraro]

Created attachment 280403 [details]
[IMAGE] TypeErrors everywhere

[Blaze Burg]

This seems like a dupe of https://bugs.webkit.org/show_bug.cgi?id=153911.

[Timothy Hatcher]

*** This bug has been marked as a duplicate of bug 153911 ***

[Joseph Pecoraro]

Similar, but I'd have considered them different.

[Joseph Pecoraro]

I'm going to unduplicated this, because it is different. I have a fix for this.

[Joseph Pecoraro]

Created attachment 282395 [details]
[IMAGE] document.body before

[Joseph Pecoraro]

Created attachment 282396 [details]
[IMAGE] document.body after

[Joseph Pecoraro]

Created attachment 282397 [details]
[IMAGE] LoadEvent before

[Joseph Pecoraro]

Created attachment 282398 [details]
[IMAGE] LoadEvent after

[Joseph Pecoraro]

Created attachment 282400 [details]
[PATCH] Proposed Fix

[Joseph Pecoraro]

So the way this works is:

The preview will show native accessors as values in the preview:

    js> loadEvent
    ▶︎ Event { type: "foo", ... }

And when you expand, the first expansion _conveniently_ immediately shows you both own properties/functions and native getters up in the prototype chain:

    js> loadEvent
    ▼ Event
        [B] ownPropertyBoolean: true
        [S] type: "foo"
        ...
    ▶︎ Event Prototype

And when you expand the prototypes, it will show the individual properties/functions + accessors on those prototypes:

    js> loadEvent
    ▼ Event
        [B] ownPropertyBoolean: true
        [S] type: "foo"
        ...
    ▼ Event Prototype
        [?] type: (Get)
        ...
    ▶︎ Object Prototype

This is the best of both worlds. Quick access to values. Yet still having the ability to ultimately find out exactly which prototype the accessor came from.

[Timothy Hatcher]

Comment on attachment 282400 [details]
[PATCH] Proposed Fix

View in context: https://bugs.webkit.org/attachment.cgi?id=282400&action=review

> Source/JavaScriptCore/inspector/InjectedScriptSource.js:647
> +                        // Developers may create such a descriptors, so we should be resilient:

"such a descriptors" => "such a descriptor"

[Joseph Pecoraro]

Created attachment 282413 [details]
[PATCH] For Landing

[Joseph Pecoraro]

<https://trac.webkit.org/changeset/202666>