Custom markers in PyTest - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of pytest with custom marker skip

What will be the output when running this pytest code with the custom marker @pytest.mark.skip(reason="Not ready") applied to test_feature()?

PyTest

import pytest

@pytest.mark.skip(reason="Not ready")
def test_feature():
    assert 1 == 1

def test_other():
    assert 2 == 2

A Both tests run and pass; overall result: 2 passed

B test_feature raises an error; test_other passes; overall result: 1 passed, 1 error

C test_feature fails due to skip marker; test_other passes; overall result: 1 passed, 1 failed

D test_feature is skipped; test_other passes; overall result: 1 passed, 1 skipped

💡 Hint

The skip marker prevents the test from running but counts as skipped, not failed.

The @pytest.mark.skip marker tells pytest to skip the test. The test is not run, so it neither passes nor fails. The other test runs and passes normally. The test report shows one passed and one skipped test.

❓ assertion

intermediate

Correct assertion for custom marker usage

Which assertion correctly verifies that a test function is marked with a custom marker named slow in pytest?

PyTest

import pytest

def test_example():
    pass

# Assume test_example is marked with @pytest.mark.slow

A assert test_example.has_marker('slow')

B assert any(marker.name == 'slow' for marker in test_example.pytestmark)

C assert 'slow' in test_example.pytestmark

D assert test_example.marker == 'slow'

💡 Hint

pytest stores markers as objects with a name attribute in the pytestmark list.

pytest stores markers in a list called pytestmark attached to the test function. Each marker is an object with a name attribute. To check if a marker named 'slow' is present, you must check if any marker's name equals 'slow'.

🔧 Debug

advanced

Debugging marker registration error

Given this pytest configuration snippet, what is the cause of the error when trying to use the custom marker integration?

PyTest

# content of pytest.ini
[pytest]
markers =
    integration: mark test as integration test

# test_sample.py
import pytest

@pytest.mark.integration
def test_api():
    assert True

A Indentation error before test_api function definition causes syntax error

B Marker 'integration' is not registered in pytest.ini

C Missing import of integration marker causes NameError

D pytest.ini file is ignored unless placed in root directory

💡 Hint

Check the indentation of the test function definition line.

The test function test_api has an extra space before its definition line, causing an IndentationError. This prevents pytest from running the test and using the marker properly.

❓ framework

advanced

Using custom markers to select tests

Which pytest command line option runs only tests marked with the custom marker database?

A pytest -m database

B pytest --run-database

C pytest --markers=database

D pytest -k database

💡 Hint

The -m option filters tests by marker expression.

The -m option in pytest runs tests that match the given marker expression. Using pytest -m database runs only tests marked with @pytest.mark.database.

🧠 Conceptual

expert

Best practice for custom marker documentation

Why is it important to declare custom markers in the pytest.ini file under the markers section?

A To allow markers to be used only in test classes but not in functions

B To register markers as built-in pytest markers for performance optimization

C To avoid pytest warnings about unknown markers and provide documentation for users

D To enable pytest to automatically skip tests with those markers

💡 Hint

pytest warns if it encounters markers not declared in configuration.

Declaring custom markers in pytest.ini under the markers section prevents pytest from showing warnings about unknown markers. It also serves as documentation for other developers about the purpose of each marker.