Built-in markers (skip, skipif, xfail) in PyTest - Test Execution Trace

Test Overview

This test demonstrates how pytest built-in markers skip, skipif, and xfail control test execution. It verifies that tests are skipped or expected to fail under certain conditions.

Test Code - pytest

PyTest

import pytest

@pytest.mark.skip(reason="Skipping this test always")
def test_always_skipped():
    assert False  # This should never run

@pytest.mark.skipif(True, reason="Condition is True, so skip")
def test_skipped_if_true():
    assert False  # This should be skipped

@pytest.mark.xfail(reason="Known bug, expected failure")
def test_expected_failure():
    assert 1 == 2  # This test is expected to fail

@pytest.mark.xfail(reason="Known bug, but fixed now", strict=True)
def test_strict_xfail():
    assert 1 == 1  # This test should pass, so strict xfail will fail the test

Execution Trace - 11 Steps

Step	Action	System State	Assertion	Result
1	pytest starts test run	pytest test runner initialized	-	PASS
2	pytest discovers test_always_skipped and applies @pytest.mark.skip	test_always_skipped marked to skip with reason	-	PASS
3	pytest skips test_always_skipped without running it	test_always_skipped skipped	test_always_skipped is skipped	PASS
4	pytest discovers test_skipped_if_true and applies @pytest.mark.skipif with condition True	test_skipped_if_true marked to skip if condition is True	-	PASS
5	pytest skips test_skipped_if_true because condition is True	test_skipped_if_true skipped	test_skipped_if_true is skipped	PASS
6	pytest discovers test_expected_failure and applies @pytest.mark.xfail	test_expected_failure marked as expected failure	-	PASS
7	pytest runs test_expected_failure which asserts 1 == 2 (fails)	test_expected_failure executed and failed	test_expected_failure failure matches xfail expectation	PASS
8	pytest marks test_expected_failure as xfail (expected failure)	test_expected_failure result recorded as xfail	test_expected_failure is reported as expected failure	PASS
9	pytest discovers test_strict_xfail and applies @pytest.mark.xfail with strict=True	test_strict_xfail marked as strict xfail	-	PASS
10	pytest runs test_strict_xfail which asserts 1 == 1 (passes)	test_strict_xfail executed and passed	test_strict_xfail passed but marked strict xfail	FAIL
11	pytest reports test_strict_xfail as failure because strict xfail expects failure	test_strict_xfail result recorded as failure	strict xfail test passed unexpectedly, causing failure	FAIL

Failure Scenario

Failing Condition: test marked with strict xfail passes unexpectedly

Execution Trace Quiz - 3 Questions

What happens to a test marked with @pytest.mark.skip?

A The test is not run and marked as skipped

B The test runs but is expected to fail

C The test runs and must pass

D The test runs and is ignored if it fails

Key Result

Use pytest markers skip, skipif, and xfail to control test execution flow and handle known issues clearly. Strict xfail helps detect when a bug is fixed but the marker was not updated.