Bug 105162 – Web Inspector: MediaQueryList listener silently catches errors

• Status: RESOLVED
• Resolution: FIXED
• Component: Web Inspector (Deprecated)

[Yury Semikhatsky]

Upstreaming Chromium issue: http://code.google.com/p/chromium/issues/detail?id=162651

Steps to reproduce the problem:
1. Get a media query list
2. Add a listener with an error inside
3. Trigger the listener

	var theMediaQueryList = window.matchMedia("screen and (max-width: 600px)");

	theMediaQueryList.addListener(function(aMediaQueryList) {
		console.log("Function started");
		objectThatDoesNotExist.produceError();
		console.log("Function ended");
	});

http://www.developedbyme.com/dbm-repository/bugs/mediaQueryListCatchError.html

What is the expected behavior?
The error to be displayed in the console.

What went wrong?
Nothing is printed code in the functions is stopped.

[Yury Semikhatsky]

Created attachment 179715 [details]
Patch

[Yury Semikhatsky]

Created attachment 179716 [details]
Patch

[Yury Semikhatsky]

(In reply to comment #2)
> Created an attachment (id=179716) [details]
> Patch

I'd like to test this but because of crbug.com/40680 LayoutTestController.setViewModeMediaFeature is not implemented for Chromium yet which makes it hard to emulate media query changes.

[Yury Semikhatsky]

Created attachment 179717 [details]
Patch

[Yury Semikhatsky]

Created attachment 179718 [details]
Patch

[Pavel Feldman]

Comment on attachment 179718 [details]
Patch

A test?

[Yury Semikhatsky]

(In reply to comment #6)
> (From update of attachment 179718 [details])
> A test?

Any suggestions on how to write it without LayoutTestController.setViewModeMediaFeature ?

[Yury Semikhatsky]

Created attachment 179908 [details]
Patch

[Yury Semikhatsky]

(In reply to comment #7)
> (In reply to comment #6)
> > (From update of attachment 179718 [details] [details])
> > A test?
> 
> Any suggestions on how to write it without LayoutTestController.setViewModeMediaFeature ?

Added a layout test for this. Kudos to apavlov for his suggestions on this!

[Alexander Pavlov (apavlov)]

Comment on attachment 179908 [details]
Patch

View in context: https://bugs.webkit.org/attachment.cgi?id=179908&action=review

Please address the comments prior to landing.

> LayoutTests/http/tests/inspector-protocol/resources/protocol-test.js:67
> +        return;

The common behavior in this situation is to output something like "This test requires DumpRenderTree", since oftentimes tests can be run manually in the browser.

> LayoutTests/inspector-protocol/media-query-listener-exception-expected.txt:3
> +Test that uncaught exception in MediaQueryListListener will be reported to the console. On success you should see to exceptions in the listener logged to the console(first time when the device metrics are overriden and second - when they are restored). Bug 105162.

"to exceptions" -> "two exceptions"
space before '('
"device metrics are" -> "media type is"
"overriden" -> "overridden"

[Yury Semikhatsky]

(In reply to comment #10)
> (From update of attachment 179908 [details])
> View in context: https://bugs.webkit.org/attachment.cgi?id=179908&action=review
> 
> Please address the comments prior to landing.
> 
> > LayoutTests/http/tests/inspector-protocol/resources/protocol-test.js:67
> > +        return;
> 
> The common behavior in this situation is to output something like "This test requires DumpRenderTree", since oftentimes tests can be run manually in the browser.
> 
Done.

> > LayoutTests/inspector-protocol/media-query-listener-exception-expected.txt:3
> > +Test that uncaught exception in MediaQueryListListener will be reported to the console. On success you should see to exceptions in the listener logged to the console(first time when the device metrics are overriden and second - when they are restored). Bug 105162.
> 
> "to exceptions" -> "two exceptions"
> space before '('
> "device metrics are" -> "media type is"
> "overriden" -> "overridden"
Done.

[Yury Semikhatsky]

Committed r138003: <http://trac.webkit.org/changeset/138003>

[János Badics]

The test (inspector-protocol/media-query-listener-exception.html) you have added in 138003 fails on Qt, Apple Lion, GTK and EFL with the same diff:

--- /ramdisk/qt-linux-64-release/build/layout-test-results/inspector-protocol/media-query-listener-exception-expected.txt 
+++ /ramdisk/qt-linux-64-release/build/layout-test-results/inspector-protocol/media-query-listener-exception-actual.txt 
@@ -1,5 +1,5 @@
-CONSOLE MESSAGE: line 13: Uncaught ReferenceError: objectThatDoesNotExist is not defined
-CONSOLE MESSAGE: line 13: Uncaught ReferenceError: objectThatDoesNotExist is not defined
+CONSOLE MESSAGE: line 13: 
+CONSOLE MESSAGE: line 13: 
 Test that uncaught exception in MediaQueryListListener will be reported to the console. On success you should see two exceptions in the listener logged to the console (first time when the media type is overridden and second - when they are restored). Bug 105162.

Could you have a look at it please?

[János Badics]

Is it maybe because the differences in working of JSC and V8?

[Yury Semikhatsky]

(In reply to comment #14)
> Is it maybe because the differences in working of JSC and V8?

Yes, it is. Ilya landed updated expectations: http://trac.webkit.org/changeset/138010