Ajax test failure on Android 4.0-4.3

[Krinkle]

Before:

• http://swarm.jquery.org/job/5785
• Commit 3fcddd6 (jQuery Periodic, 18 July 2017)

After:

• http://swarm.jquery.org/job/5848
• Commit 262acc6 (jQuery Periodic, 24 July 2017)

Possibly relevant commits:

• 928c580 Tests: Reduce the abort timeout for simple focus testing
• deba37e Tests: Simulate events when CI hinders use of native ones
• 262acc6 Ajax: add an ontimeout handler to all requests (@timmywil, Ajax request timeout doesn't trigger fail() or always() in Safari #3586, PR for #3586 (Safari xhr timeout) #3590)

[mgol]

Looks like a dupe of #3743? Why single out ajax failures when all tests just timeout?

[Krinkle]

@mgol This report is about an assertion failure (1 test failure) in the Ajax test suite, happening on Android 4 (Android 4.1, 4.2, 4.3 and presumably 4.0 as well).

See the screenshot and difference between before/after. The time outs in all tests Android 4.0 are a pre-existing issue since one week earlier, filed separately as #3743.

[mgol]

Ah, it's about 4.x, not just 4.0, I misread.

[timmywil]

It seems Android 4.0-4.3 does not call the ontimeout handler. This test was added when we added an ontimeout responder. The test ensures that we actually respond to native calls to ontimeout. If the browser never calls ontimeout, we aren't necessarily doing something wrong.

I see 2 options. (1) Add a workaround to use a setTimeout and call ontimeout ourselves manually, but that sounds error-prone and hacky. (2) Don't run this test in Android 4.x.

I lean towards 2.

[mgol]

I'm for 2 as well.

We should run the tests only if 'ontimeout' in new XMLHttpRequest() holds, that excludes Android 4.x.