id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
37072	assertWarnsMessage() also ignores entire warning category	Mike Edmunds		"`assertWarnsMessage(category, message)` implicitly does the equivalent of `ignore_warnings(category)`. As a result, tests for particular deprecation warnings can overlook other, unrelated deprecation warnings coming from the code being tested.

You would expect the second test case below to cause an error for `RemovedInDjango70Warning: Unrelated deprecation`, but it actually passes:

{{{#!python
class SomeTests(SimpleTestCase):
    def test_this_errors_as_expected(self):
        # ERROR: RemovedInDjango70Warning: Unrelated deprecation
        warnings.warn(""Unrelated deprecation"", RemovedInDjango70Warning)

    def test_so_this_should_also_error_but_does_not(self):
        with self.assertWarnsMessage(RemovedInDjango70Warning, ""Expected deprecation""):
            warnings.warn(""Expected deprecation"", RemovedInDjango70Warning)
            # This gets ignored.
            warnings.warn(""Unrelated deprecation"", RemovedInDjango70Warning)

    def test_duplicate_warnings_should_maybe_also_error(self):
        with self.assertWarnsMessage(RemovedInDjango70Warning, ""Expected deprecation""):
            warnings.warn(""Expected deprecation"", RemovedInDjango70Warning)
            # This also gets ignored. Maybe it shouldn't?
            warnings.warn(""Expected deprecation"", RemovedInDjango70Warning)
}}}

The problem is `assertWarnsMessage()` and `assertRaisesMessage()` try to share `SimpleTestCase._assertFooMessage()`, which wraps `assertWarns()` and `assertRaises()` respectively. But those methods aren't really parallel: there can be only one error raised, but execution can continue after a warning. `assertWarns(category)` captures ''all'' warnings in the category."	Bug	new	Testing framework	6.0	Normal				Unreviewed	0	0	0	0	0	0