Fix integration test "FreeText Editor Paste some html must check that pasting html just keep the text"

[timvandermeij]

This integration test is quite new, but has failed a couple of times on (as far as I have seen only) the Windows bot now with the following traceback:

1) FreeText Editor Paste some html must check that pasting html just keep the text
  Message:
�[31m    In firefox:
        Expected 'FooFooBar
        OofHello PDF.js World !!' to equal 'FooBar
        OofHello PDF.js World !!'.�[0m
  Stack:
        at <Jasmine>
        at file:///C:/pdfjs/botio-files-pdfjs/private/d21e23ccf06497a/test/integration/freetext_editor_spec.mjs:3667:57
        at process.processTicksAndRejections (node:internal/process/task_queues:95:5)
        at async Promise.all (index 0)
        at async UserContext.<anonymous> (file:///C:/pdfjs/botio-files-pdfjs/private/d21e23ccf06497a/test/integration/freetext_editor_spec.mjs:3567:7)

The most recent logs can be found here: http://54.193.163.58:8877/d21e23ccf06497a/output.txt

It was introduced in commit 2dbd7ac and it fails at https://github.com/mozilla/pdf.js/blob/master/test/integration/freetext_editor_spec.mjs#L3666-L3667.

@calixteman Do you have an idea why this could be failing intermittently?

[calixteman]

It seems that Foo is pasted several times which means that we try to paste the string but nothing happened before 100ms and then another paste is triggered but finally we've two pasted strings.

pdf.js/test/integration/freetext_editor_spec.mjs

Line 3622 in e78ce74

await pasteFromClipboard(

and

pdf.js/test/integration/test_utils.mjs

Line 235 in e78ce74

while (!hasPasteEvent) {

We could try to increase the default timeout to 500ms.
I know that having hardcoded timeout isn't ideal but I cannot image an other solution, I'll try to think about that.

[timvandermeij]

I think, to buy us time and reduce how often this occurs since it just happened again at http://54.193.163.58:8877/f423fd1265d6552/output.txt, increasing the timeouts in that test to e.g. 200 ms or more could work as a temporary measure. I would feel a bit better about that if the current failures can be reproduced on a Windows system (I currently don't have one around) and to verify that a higher timeout value indeed "fixes" it, instead of us having to try various timeout values experimentally.

For the proper fix, we should probably try to remove the waitForTimeout usage by changing the test to not have to wait for something that won't happen. Maybe that can be done by changing the order of operations in the tests, i.e. by putting the pastes where no action is expected at the very end so a valid paste in between cannot mess up the assertions, or by splitting off the pastes where nothing is expected to happen into another test so they can't conflict? I don't know the details of this particular test, but hopefully something like that should be doable.

[timvandermeij]

The temporary fix of increasing the timeouts sadly didn't do as much as I had hoped (see the PR above), so it looks like we'll have to keep is as is for now and indeed think about the proper fix in the meantime.

[timvandermeij]

Note that, while this test fails intermittently most often on Windows, it can also occur on Linux. However, the traceback is slightly different and includes an IndexSizeError that I haven't seen in the Windows logs yet. Snippet from http://54.241.84.105:8877/4205770be581237/output.txt:

Failures:
1) FreeText Editor Paste some html must check that pasting html just keep the text
  Message:
�[31m    In firefox:
        Expected 'Foo
        Bar
        OofHello PDF.js World !!' to equal 'FooHello PDF.js World !!'.�[0m
  Stack:
        at <Jasmine>
        at file:///home/ubuntu/pdfjs/botio-files-pdfjs/private/4205770be581237/test/integration/freetext_editor_spec.mjs:3645:57
        at async Promise.all (index 0)
        at async UserContext.<anonymous> (file:///home/ubuntu/pdfjs/botio-files-pdfjs/private/4205770be581237/test/integration/freetext_editor_spec.mjs:3576:7)
  Message:
�[31m    IndexSizeError: Selection.setPosition: The offset is out of range.�[0m
  Stack:
        at evaluate (evaluate at select (file:///home/ubuntu/pdfjs/botio-files-pdfjs/private/4205770be581237/test/integration/freetext_editor_spec.mjs:3621:18), <anonymous>:2:40)
        at evaluate (evaluate at select (file:///home/ubuntu/pdfjs/botio-files-pdfjs/private/4205770be581237/test/integration/freetext_editor_spec.mjs:3621:18), <anonymous>:5: