@pytest.mark.xfail for expected failures - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does @pytest.mark.xfail do in a pytest test?

It marks a test as an expected failure. If the test fails, pytest reports it as an expected failure, not a test failure.

intermediate

How does pytest report a test marked with @pytest.mark.xfail when it actually passes?

Pytest reports it as an unexpected pass because the test was expected to fail but passed.

beginner

Why would you use @pytest.mark.xfail in your test suite?

To acknowledge known bugs or incomplete features without failing the whole test suite, allowing progress while tracking issues.

intermediate

What happens if a test marked with @pytest.mark.xfail(strict=True) unexpectedly passes?

The test suite will fail because strict mode treats unexpected passes as errors.

beginner

Show a simple example of using @pytest.mark.xfail in a test function.

import pytest

@pytest.mark.xfail
def test_example():
    assert 1 == 2  # This test is expected to fail

What does @pytest.mark.xfail indicate about a test?

A The test should be skipped

B The test is expected to fail

C The test must always pass

D The test is ignored

@pytest.mark.xfail marks a test as expected to fail due to known issues.

If a test marked with @pytest.mark.xfail passes, how does pytest report it by default?

A Unexpected pass

B Pass

C Fail

D Skipped

Pytest reports it as an unexpected pass because it was expected to fail.

What does adding strict=True to @pytest.mark.xfail do?

A Fails the test suite if the test unexpectedly passes

B Runs the test twice

C Ignores the test result

D Skips the test

Strict mode makes pytest fail the suite if an expected failure test passes unexpectedly.

Which of these is a good reason to use @pytest.mark.xfail?

A To hide all test failures

B To speed up test execution

C To skip tests permanently

D To document known bugs without failing the suite

It helps track known bugs while allowing the test suite to run smoothly.

What happens if you do not mark a failing test with @pytest.mark.xfail?

A The test passes anyway

B The test is ignored

C The test suite fails

D The test is skipped

Unmarked failing tests cause the test suite to fail.

Explain how @pytest.mark.xfail helps manage tests with known bugs.

Think about how you handle bugs that are not fixed yet but don't want to block progress.

Describe the difference between @pytest.mark.xfail with and without strict=True.

Consider how strict mode changes the test suite behavior when a test passes unexpectedly.