cpython/Lib/test/test_frozen.py
Neil Schemenauer 1eaa1169c5
Add a minimal unit test for Python/frozen.c. (#2995)
If the marshal or bytecode formats get changed, frozen.c needs to
be updated as well.  It can be easy to miss this step and not doing
so can cause test_importlib to crash in mysterious ways.  Add an
explict unit test to make it easier to track down the problem.
2017-12-02 13:54:00 -08:00

30 lines
970 B
Python

"""Basic test of the frozen module (source is in Python/frozen.c)."""
# The Python/frozen.c source code contains a marshalled Python module
# and therefore depends on the marshal format as well as the bytecode
# format. If those formats have been changed then frozen.c needs to be
# updated.
#
# The test_importlib also tests this module but because those tests
# are much more complicated, it might be unclear why they are failing.
# Invalid marshalled data in frozen.c could case the interpreter to
# crash when __hello__ is imported.
import sys
import unittest
from test.support import captured_stdout
from importlib import util
class TestFrozen(unittest.TestCase):
def test_frozen(self):
name = '__hello__'
if name in sys.modules:
del sys.modules[name]
with captured_stdout() as out:
import __hello__
self.assertEqual(out.getvalue(), 'Hello world!\n')
if __name__ == '__main__':
unittest.main()