Closed Bug 1594871 Opened 3 months ago Closed 2 months ago

Intermittent remote/test/browser/page/browser_captureScreenshot.js | Size of quality 10 is smaller than default -


(Remote Protocol :: Page, defect, P1)



(firefox-esr68 unaffected, firefox70 unaffected, firefox71 unaffected, firefox72 fixed)

Firefox 72
Tracking Status
firefox-esr68 --- unaffected
firefox70 --- unaffected
firefox71 --- unaffected
firefox72 --- fixed


(Reporter: intermittent-bug-filer, Assigned: whimboo)




(Keywords: intermittent-failure, regression, Whiteboard: [puppeteer-alpha])


(1 file)

Filed by: csabou [at]
Parsed log:
Full log:

[task 2019-11-07T20:09:09.685Z] 20:09:09 INFO - TEST-PASS | remote/test/browser/page/browser_captureScreenshot.js | Size of quality 100 is larger than default -
[task 2019-11-07T20:09:09.689Z] 20:09:09 INFO - Buffered messages finished
[task 2019-11-07T20:09:09.690Z] 20:09:09 INFO - TEST-UNEXPECTED-FAIL | remote/test/browser/page/browser_captureScreenshot.js | Size of quality 10 is smaller than default -
[task 2019-11-07T20:09:09.691Z] 20:09:09 INFO - Stack trace:
[task 2019-11-07T20:09:09.692Z] 20:09:09 INFO - chrome://mochikit/content/browser-test.js:test_ok:1299
[task 2019-11-07T20:09:09.693Z] 20:09:09 INFO - chrome://mochitests/content/browser/remote/test/browser/page/browser_captureScreenshot.js:asJPEGFormatAndQuality:140
[task 2019-11-07T20:09:09.694Z] 20:09:09 INFO - chrome://mochitests/content/browser/remote/test/browser/head.js:this.add_task/<:42
[task 2019-11-07T20:09:09.695Z] 20:09:09 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest/<:1069
[task 2019-11-07T20:09:09.696Z] 20:09:09 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest:1104
[task 2019-11-07T20:09:09.697Z] 20:09:09 INFO - chrome://mochikit/content/browser-test.js:nextTest/<:932
[task 2019-11-07T20:09:09.697Z] 20:09:09 INFO - chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:SimpleTest.waitForFocus/waitForFocusInner/focusedOrLoaded/<:805
[task 2019-11-07T20:09:09.698Z] 20:09:09 INFO - CDP client closed
[task 2019-11-07T20:09:09.700Z] 20:09:09 INFO - GECKO(2036) | 1573157349549 RemoteAgent INFO Stopped listening
[task 2019-11-07T20:09:09.703Z] 20:09:09 INFO - CDP server stopped
[task 2019-11-07T20:09:09.704Z] 20:09:09 INFO - Leaving test bound
[task 2019-11-07T20:09:09.704Z] 20:09:09 INFO - GECKO(2036) | MEMORY STAT | vsize 20975078MB | residentFast 1137MB
[task 2019-11-07T20:09:09.705Z] 20:09:09 INFO - TEST-OK | remote/test/browser/page/browser_captureScreenshot.js | took 7637ms

Pushed by
Disable the racy sub-test. r=whimboo
Depends on: 1587846
See Also: → 1590933

Here the data related to those checks:

 0:09.18 INFO *** infoDefault lenght: 21020
 0:09.18 INFO *** info100 lenght: 38092
 0:09.18 PASS Size of quality 100 is larger than default -
 0:09.18 INFO *** info10 lenght: 21272

The content length of a jpeg image with 10% quality is larger than one with 80%. Maybe there is a baseline, or we didn't screenshot correctly. I will extract the images and upload them as reference in a moment.

Assignee: nobody → hskupin
Priority: P5 → P1

The problem here is that the screenshot with default quality which is taken first, is blank! As such the 10% quality one which is taken some milliseconds later is larger because it contains the expected output.

That means that the suspicion from Matt was right, and we do not wait long enough for the data URL having finished loading.

What's strange is that we make use of BrowserTestUtils.loadURI in combination with BrowserTestUtils.browserLoaded():

Why aren't other mochitests broken which do the same? Maybe none of those make use of data URLs, and as such a required fix for browserLoaded() was missing? It clearly looks like a regression from bug 1593560 and especially

I'm not sure what this change actually means, and for which additional events browserLoaded() would have to wait for now.

Gijs, or Matt could you please help?

Flags: needinfo?(matt.woodrow)
Flags: needinfo?(gijskruitbosch+bugs)
Keywords: regression
Regressed by: 1593560

(In reply to :Gijs (he/him) from comment #6)

(In reply to Henrik Skupin (:whimboo) [⌚️UTC+2] from comment #5)

It clearly looks like a regression from bug 1593560 and especially

Uh, really? that landed ages ago and this bug is new today. Why do you think this is the regressor?

Oh, sorry, I assumed this was the generic enabling of DocumentChannel. I don't know, then. The code in the utility function looks correct to me in the sense that it waits for the load. Perhaps it should be waiting for a paint event too?

Flags: needinfo?(hskupin)

Maybe, but now I have seen the problem. loadURL() in our head.js file is async, but the test doesn't use await! What a silly mistake.

I will have a look at all the existent tests to get this fixed. Sorry for the noise.

Blocks: 1590933
See Also: 1590933
Flags: needinfo?(matt.woodrow)
Pushed by
[remote] Callers of loadURL() in browser_captureScreenshot.js have to use await. r=remote-protocol-reviewers,ato
Whiteboard: [puppeteer-alpha]

This is fixed now!

Closed: 2 months ago
Keywords: leave-open
Resolution: --- → FIXED
Target Milestone: --- → Firefox 72
Duplicate of this bug: 1590933
You need to log in before you can comment on or make changes to this bug.