Switch to pytest asserts

[pquentin]

They're easier to read and produce better error messages. This was done mostly automatically with the self_assert unittest2pytest fix. (I had to modify unittest2pytest to use fissix instead of lib2to3 as the latter choked on various files.)

I also had to change many lines from assert 0 == value to assert value == 0 to please pytest. This isn't a useful pattern in Python because assert 0 = value is a syntax error anyway.

I may have some pylint issues left to fix, but wanted to hear about the general idea first.

[danielmitterdorfer]

@elasticmachine test this please

[pquentin]

This kind of large transformation is much easier to do once automatic code formatting is in place, have you considered switching to black?

I also need to change the assertAlmostEqual transformation to use math.isclose, which is the idiomatic way to compare floats since Python 3.5. The current round/abs hacks are very difficult to understand.

I can also do this file by file or assert type by assert type to make this easier to review in small chunks.

[danielmitterdorfer]

Thanks for your PR! IMHO the general direction makes sense.

I have triggered CI and as you suspected there are indeed there are a couple of linter issues at the moment:

************* Module tests.utils.opts_test
tests/utils/opts_test.py:37:0: C0301: Line too long (145/140) (line-too-long)
************* Module tests.mechanic.mechanic_test
tests/mechanic/mechanic_test.py:57:0: C0301: Line too long (150/140) (line-too-long)
************* Module tests.mechanic.team_test
tests/mechanic/team_test.py:155:0: C0301: Line too long (203/140) (line-too-long)
tests/utils/opts_test.py:37:0: C0301: Line too long (145/140) (line-too-long)
tests/mechanic/team_test.py:155:0: C0301: Line too long (203/140) (line-too-long)
************* Module tests.config_test
tests/config_test.py:293:0: C0301: Line too long (141/140) (line-too-long)
************* Module tests.track.params_test
tests/track/params_test.py:138:0: C0301: Line too long (153/140) (line-too-long)
tests/track/params_test.py:141:0: C0301: Line too long (143/140) (line-too-long)
tests/track/params_test.py:797:0: C0301: Line too long (143/140) (line-too-long)
tests/track/params_test.py:1373:0: C0301: Line too long (149/140) (line-too-long)
tests/track/params_test.py:1797:0: C0301: Line too long (142/140) (line-too-long)
tests/mechanic/mechanic_test.py:57:0: C0301: Line too long (150/140) (line-too-long)
************* Module tests.mechanic.supplier_test
tests/mechanic/supplier_test.py:34:0: C0301: Line too long (142/140) (line-too-long)
tests/mechanic/supplier_test.py:37:0: C0301: Line too long (207/140) (line-too-long)
tests/mechanic/supplier_test.py:177:0: C0301: Line too long (151/140) (line-too-long)
tests/mechanic/supplier_test.py:183:0: C0301: Line too long (151/140) (line-too-long)
tests/mechanic/supplier_test.py:542:0: C0301: Line too long (166/140) (line-too-long)
tests/mechanic/supplier_test.py:555:0: C0301: Line too long (164/140) (line-too-long)
************* Module tests.telemetry_test
tests/telemetry_test.py:291:0: C0301: Line too long (157/140) (line-too-long)
tests/telemetry_test.py:304:0: C0301: Line too long (150/140) (line-too-long)
tests/telemetry_test.py:1875:0: C0301: Line too long (158/140) (line-too-long)
tests/telemetry_test.py:2531:0: C0301: Line too long (163/140) (line-too-long)
tests/telemetry_test.py:2544:0: C0301: Line too long (159/140) (line-too-long)
************* Module tests.metrics_test
tests/metrics_test.py:190:0: C0301: Line too long (150/140) (line-too-long)
tests/metrics_test.py:201:0: C0301: Line too long (152/140) (line-too-long)
tests/metrics_test.py:213:0: C0301: Line too long (149/140) (line-too-long)
tests/metrics_test.py:226:0: C0301: Line too long (151/140) (line-too-long)
************* Module tests.track.loader_test
tests/track/loader_test.py:240:0: C0301: Line too long (150/140) (line-too-long)
tests/track/loader_test.py:1759:0: C0301: Line too long (144/140) (line-too-long)
tests/track/loader_test.py:1848:0: C0301: Line too long (145/140) (line-too-long)
tests/track/loader_test.py:1882:0: C0301: Line too long (146/140) (line-too-long)
tests/track/loader_test.py:1936:0: C0301: Line too long (149/140) (line-too-long)
tests/track/loader_test.py:1966:0: C0301: Line too long (153/140) (line-too-long)
tests/track/loader_test.py:2969:0: C0301: Line too long (153/140) (line-too-long)
tests/track/loader_test.py:3005:0: C0301: Line too long (149/140) (line-too-long)
tests/track/loader_test.py:3519:0: C0301: Line too long (152/140) (line-too-long)
tests/track/loader_test.py:3557:0: C0301: Line too long (151/140) (line-too-long)
************* Module tests.driver.runner_test
tests/driver/runner_test.py:192:0: C0301: Line too long (155/140) (line-too-long)
tests/driver/runner_test.py:2177:0: C0301: Line too long (151/140) (line-too-long)
tests/driver/runner_test.py:2193:0: C0301: Line too long (149/140) (line-too-long)
tests/driver/runner_test.py:2456:0: C0301: Line too long (154/140) (line-too-long)
tests/driver/runner_test.py:2673:0: C0301: Line too long (152/140) (line-too-long)
tests/driver/runner_test.py:2751:0: C0301: Line too long (152/140) (line-too-long)
tests/driver/runner_test.py:2796:0: C0301: Line too long (156/140) (line-too-long)
tests/driver/runner_test.py:2874:0: C0301: Line too long (156/140) (line-too-long)
tests/driver/runner_test.py:2920:0: C0301: Line too long (157/140) (line-too-long)
tests/driver/runner_test.py:2999:0: C0301: Line too long (157/140) (line-too-long)

You can also see them locally when running make lint.

[danielmitterdorfer]

This kind of large transformation is much easier to do once automatic code formatting is in place, have you considered switching to black?

black is on our radar but I fear that we won't have much capacity at the moment to work on it.

I also need to change the assertAlmostEqual transformation to use math.isclose, which is the idiomatic way to compare floats since Python 3.5. The current round/abs hacks are very difficult to understand.

That's great. :)

I can also do this file by file or assert type by assert type to make this easier to review in small chunks.

Given the mostly mechanical nature, it's ok for me to do it all at once. The changes themselves should be quick to review even if it spans this many files.

[pquentin]

Thanks, I'll fix the line-too-long lint issues. (I've ran pylint, but am not familiar with the output yet, and don't understand when it fails or does not fail.)

black is on our radar but I fear that we won't have much capacity at the moment to work on it.

Is it just about the work to set it up, or are there other concerns?

[pquentin]

Closing as I haven't been able to give this pull request the attention it needs, sorry! And it's going to be restarted from scratch anyway.