README.md

pytest-raises-without-match

This custom pylint rule disallows calling pytest.raises without a match argument to avoid capturing unintended exceptions and eliminate false-positive tests.

Example

Suppose we want to test this function throws Exception("bar") when condition2 is satisfied.

def func():
    if condition1:
        raise Exception("foo")

    if condition2:
        raise Exception("bar")

Bad

def test_func():
    with pytest.raises(Exception):
        func()

• This test passes when condition1 is unintentionally satisfied.
• Future code readers will struggle to identify which exception pytest.raises should match.

Good

def test_func():
    with pytest.raises(Exception, match="bar"):
        func()

• This test fails when condition1 is unintentionally satisfied.
• Future code readers can quickly identify which exception pytest.raises should match by searching bar.

How to disable this rule

def test_func():
    with pytest.raises(Exception):  # pylint: disable=pytest-raises-without-match
        func()

References

• https://docs.pytest.org/en/latest/how-to/assert.html#assertions-about-expected-exceptions
• https://docs.pytest.org/en/latest/reference/reference.html#pytest.raises