gh-126028: Add more tests for msvcrt module #126029
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Co-authored-by: sobolevn <mail@sobolevn.me>
Lib/test/test_msvcrt.py
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| old = msvcrt.GetErrorMode() | ||
| self.addCleanup(msvcrt.SetErrorMode, old) | ||
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| returned = msvcrt.SetErrorMode(0) |
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Maybe test it also with non-zero value, and also with out-of-range values -1 and 2**32? If this is possible (if the test does not crash or hangs).
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This function SetErrorMode have weird behaviors and it behaves different in the test case or in a standalone test script, it sometimes returns different mode compare to the one set. I'm still try to figure it out and will update it tomorrow, thank you for the review!
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Figured out the case of SetErrorMode and found that it's actually not set the value to current, but set the bit flags on it. Currently made the test workable, but still have some concerns about it.
Added some details as a separate comment blow.
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Updated: I misunderstand the Bellow comment is wrong:Hi, I found that the [`SetErrorMode`](https://learn.microsoft.com/en-us/windows/win32/api/errhandlingapi/nf-errhandlingapi-seterrormode) actually sets the value as a bit flag to the current state, and `SetErrorMode(0)` sets it to 0.I have some code like this: import msvcrt
import unittest
class TestOther(unittest.TestCase):
def test_SetErrorMode(self):
origin = msvcrt.GetErrorMode()
print(f"origin mode: {origin}")
msvcrt.SetErrorMode(0)
current_default = msvcrt.GetErrorMode()
print(f"current default: {current_default}")
for v in (msvcrt.SEM_FAILCRITICALERRORS, msvcrt.SEM_NOGPFAULTERRORBOX,
msvcrt.SEM_NOALIGNMENTFAULTEXCEPT, msvcrt.SEM_NOOPENFILEERRORBOX):
if origin & v:
print("set v:", v)
msvcrt.SetErrorMode(v)
self.assertEqual(origin, msvcrt.GetErrorMode())
if __name__ == "__main__":
unittest.main()It reads the original mode, and sets the current mode to 0, and compares the 4 available bit flags to the original mode, and if it's true, then sets it. There is the running result: But the final result is not the same as the original mode. There is a difference of "3", so I guess the bit flags "0x1" and "0x2" don't have any effect. |
msvcrtdon't have tests #126028