1598752 - TypeError: undefined is not a constructor

Status: RESOLVED FIXED

(Core :: IPC, task)

Description

[alexander :surkov (:asurkov)]

There's a way to break a browser to make JS console (and terminal) errors are rather useless: no file, no line. For example,

TypeError: undefined is not a constructor

STRs:

• make not existing export in toolkit/actors, for example:

diff --git a/toolkit/actors/AutoCompleteChild.jsm b/toolkit/actors/AutoCompleteChild.jsm
--- a/toolkit/actors/AutoCompleteChild.jsm
+++ b/toolkit/actors/AutoCompleteChild.jsm
@@ -1,14 +1,14 @@
/* -- indent-tabs-mode: nil; js-indent-level: 2 -- /
/ This Source Code Form is subject to the terms of the Mozilla Public

• License, v. 2.0. If a copy of the MPL was not distributed with this
• file, You can obtain one at http://mozilla.org/MPL/2.0/. */

-var EXPORTED_SYMBOLS = ["AutoCompleteChild"];
+var EXPORTED_SYMBOLS = ["AutoCompleteChildThrowError"];

I suppose no matter what, but console should show somewhat useful information. Otherwise no idea where to look what's broken.

Comment 1

[Hsin-Yi Tsai (she/her) [:hsinyi]]

Edgar, is DOM: Binding a better module for this issue? Any thoughts? Thank you.

Comment 2

[Edgar Chen [:edgar]]

It is about error reporting for .jsm, it doesn't look like belonging to DOM: Binding, maybe XPConnect.
Please feel free to switch to the right component if I am wrong.

Comment 3

[Peter Van der Beken [:peterv]]

This is coming from WindowGlobalActor::ConstructActor (https://searchfox.org/mozilla-central/rev/c7b673f443407a359cc0766fb5a4ac323a1d2628/dom/ipc/WindowGlobalActor.cpp#119). Maybe we should check for undefined and report an error before calling JS::Construct?

Comment 4

[John Dai[:jdai]]

(In reply to Peter Van der Beken [:peterv] from comment #3)

This is coming from WindowGlobalActor::ConstructActor (https://searchfox.org/mozilla-central/rev/c7b673f443407a359cc0766fb5a4ac323a1d2628/dom/ipc/WindowGlobalActor.cpp#119). Maybe we should check for undefined and report an error before calling JS::Construct?

Yes, put it to my queue, I'll handle that.

Comment 5

[John Dai[:jdai]]

Attachment: Bug 1598752 - Provide useful information while constructing JSWindowActor;

Comment 6

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/cf32a7162c2b
Provide useful information while constructing JSWindowActor; r=nika

Comment 7

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/cf32a7162c2b