Function test_exception_handling_no_traceback

testing/test_assertion.py:1437–1466

Handle chain exceptions in tasks submitted by the multiprocess module (#1984).

(pytester: Pytester)

def test_exception_handling_no_traceback(pytester: Pytester) -> None:
    """Handle chain exceptions in tasks submitted by the multiprocess module (#1984)."""
    p1 = pytester.makepyfile(
        """
        from multiprocessing import Pool

        def process_task(n):
            assert n == 10

        def multitask_job():
            tasks = [1]
            with Pool(processes=1) as pool:
                pool.map(process_task, tasks)

        def test_multitask_job():
            multitask_job()
    """
    )
    pytester.syspathinsert()
    result = pytester.runpytest(p1, "--tb=long")
    result.stdout.fnmatch_lines(
        [
            "====* FAILURES *====",
            "*multiprocessing.pool.RemoteTraceback:*",
            "Traceback (most recent call last):",
            "*assert n == 10",
            "The above exception was the direct cause of the following exception:",
            "> * multitask_job()",
        ]
    )


@pytest.mark.skipif("'__pypy__' in sys.builtin_module_names")