threads.tmap() test and and fix. Unsurfaced bug #1768

[cruxicheiros]

Issue: #1768

Background: threads.tmap() was missing unit tests, so I wrote a unit test to cover the situation where the optional parameter stop_on_error is set to False. The purpose of stop_on_error is to determine whether tmap should return a result or throw an error if one or more of the function calls it makes throw exceptions.

Description: As part of my unit test's setup, it calls tmap with the stop_on_error flag set to False. However, an exception is thrown by tmap during this process because the resulting FuncResults don't have the result attribute they are expected to.

Caveats: The actual form of the unit test may need to change depending on how the issue preventing it from running is resolved. It needs to be determined what the actual correct result should be in order to write the unit test.

Finally, this is the stack trace I got before.

Error
Traceback (most recent call last):
  File "/home/clark/miniconda3/envs/pygamenv/lib/python3.8/unittest/case.py", line 60, in testPartExecutor
    yield
  File "/home/clark/miniconda3/envs/pygamenv/lib/python3.8/unittest/case.py", line 676, in run
    self._callTestMethod(testMethod)
  File "/home/clark/miniconda3/envs/pygamenv/lib/python3.8/unittest/case.py", line 633, in _callTestMethod
    method()
  File "/home/clark/Dev/pygame/pygame/test/threads_test.py", line 136, in test_tmap
    tmapped2 = list(tmap(always_excepts, data2, stop_on_error=False))
  File "/home/clark/miniconda3/envs/pygamenv/lib/python3.8/site-packages/pygame/threads/__init__.py", line 308, in <lambda>
    return map(lambda x:x.result, results)
AttributeError: 'FuncResult' object has no attribute 'result'


Assertion failed

Assertion failed


Ran 1 test in 0.036s

FAILED (errors=1)

This is my first PR to this project, so let me know if I have made mistakes in formatting it or if you need more information. Thanks!

[cruxicheiros]

Looks like the same thing has happened in the travis build, which at least is good for reproducibility

======================================================================

ERROR: test_tmap (pygame.tests.threads_test.ThreadsModuleTest)

----------------------------------------------------------------------

Traceback (most recent call last):

  File "/opt/python/cp38-cp38/lib/python3.8/site-packages/pygame/tests/threads_test.py", line 136, in test_tmap

    tmapped2 = list(tmap(always_excepts, data2, stop_on_error=False))

  File "/opt/python/cp38-cp38/lib/python3.8/site-packages/pygame/threads/__init__.py", line 308, in <lambda>

    return map(lambda x:x.result, results)

AttributeError: 'FuncResult' object has no attribute 'result'

----------------------------------------------------------------------

Ran 1478 tests in 22.190s

FAILED (errors=1)

Makefile:4: recipe for target

[MyreMylar]

I guess we need to resolve the issue with tmap before anything can be done with this unit test.

[cruxicheiros]

Yeah, that's what I think. Should I switch this to a draft and make a new issue?

[MyreMylar]

Yeah, that's what I think. Should I switch this to a draft and make a new issue?

Sounds sensible to me.

[cruxicheiros]

@MyreMylar Here: #1985

[cruxicheiros]

Modified tmap per issue #1985

[MyreMylar]

Cool.

Are you intending to look at the unfinished unit test that starts with todo in this PR? This one:

pygame/test/threads_test.py

Lines 131 to 143 in 7d3900d

	def todo_test_tmap__None_func_and_multiple_sequences(self):
	"""Using a None as func and multiple sequences"""
	self.fail()
	res = tmap(None, [1, 2, 3, 4])
	res2 = tmap(None, [1, 2, 3, 4], [22, 33, 44, 55])
	res3 = tmap(None, [1, 2, 3, 4], [22, 33, 44, 55, 66])
	res4 = tmap(None, [1, 2, 3, 4, 5], [22, 33, 44, 55])
	self.assertEqual([1, 2, 3, 4], res)
	self.assertEqual([(1, 22), (2, 33), (3, 44), (4, 55)], res2)
	self.assertEqual([(1, 22), (2, 33), (3, 44), (4, 55), (None, 66)], res3)
	self.assertEqual([(1, 22), (2, 33), (3, 44), (4, 55), (5, None)], res4)

No worries if you are not.

[cruxicheiros]

I actually hadn't noticed it and assumed that the main tmap test was the one that was unfinished. I wanted to add further tests to the main tmap test and I can have a look at the existing todo when I do that.

[illume]

I think we can merge this one in now. Further work on tmap tests can happen in other PRs.

[illume]

Thanks :)