test_magic_folder fails about 30%

[warner]

We're seeing the buildbot fail on test_magic_folder about 30% of the time, on the Ubuntu buildslave.

The specific test is test_magic_folder.MockTestAliceBob.test_alice_bob, on line 922, right after the call to Alice_to_write_file3, where it checks the object_downloaded count. It's expecting 7, and got 6.

[meejah]

I'm trying to determine if test_alice_bob actually covers any code not already covered by other test-cases -- but so far my most-consistent way to have this test fail is when running under coverage. So, I have not yet determined the answer to my question :/ but to "see it fail" your chances seem to be way higher running like coverage 'which trial' allmydata.test (those aren't backticks around "which trial", but they should be "because markdown markup").

[meejah]

If we removed test_alice_bob entirely, we'd lose coverage on the following lines:

• immutable/checker.py: 63,67,69
• magicpath.py: 30
• frontends/magic_folder.py: 792,793,990,991
• web/status.py: 917

I'm trying to confirm if we "really" cover the _check_integrity lines or if those appear covered because of an error happening (i.e. test-failure).

[meejah]

I have re-factored things and now test_alice_bob takes 1.5s which is pretty reasonable. See ​https://github.com/tahoe-lafs/tahoe-lafs/pull/313

[meejah]

313 landed, so this can be closed. Right?

[warner]

Yup.. thanks!