Installing and managing plugins in PyTest - Practice Exercises

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding pytest plugin installation

Which command correctly installs the pytest plugin named pytest-cov using pip?

A pip install pytest-cov

B pytest install pytest-cov

C pip pytest install pytest-cov

D install pytest-cov

💡 Hint

Use pip to install Python packages.

The correct way to install pytest plugins is by using pip install followed by the plugin name. 'pip install pytest-cov' installs the coverage plugin for pytest.

❓ Predict Output

intermediate

Output of pytest plugin list command

What is the expected output when running pytest --trace-config after installing the pytest-mock plugin?

A Runs tests without showing any plugin information

B Shows an error: unknown option '--trace-config'

C Lists all loaded plugins including pytest-mock with their configuration files

D Only lists built-in pytest plugins, excluding pytest-mock

💡 Hint

The --trace-config option shows plugin loading details.

The --trace-config option prints detailed info about all plugins pytest loads, including third-party plugins like pytest-mock.

❓ assertion

advanced

Correct assertion to verify plugin availability

Which assertion correctly checks if the pytest-cov plugin is active in a pytest session object named session?

A assert 'cov' in session.config.pluginmanager.get_plugins()

B assert 'pytest-cov' in session.plugins

C assert session.has_plugin('pytest-cov')

D assert session.config.pluginmanager.has_plugin('cov')

💡 Hint

Use pluginmanager's has_plugin('cov') to check for the plugin.

The pytest-cov plugin registers under the name 'cov'. The has_plugin('cov') method returns True if the plugin is loaded.

🔧 Debug

advanced

Debugging plugin import error

You installed pytest-html but get an ImportError when running pytest. Which option explains the most likely cause?

A pytest-html requires a special license key to work

B The plugin was installed in a different Python environment than the one running pytest

C pytest-html is incompatible with pytest versions above 5.0

D pytest-html must be imported manually in every test file

💡 Hint

Check your Python environments and where packages are installed.

ImportError usually means the plugin is not installed in the Python environment used by pytest. Multiple environments can cause this mismatch.

❓ framework

expert

Managing plugin versions in pytest

You want to ensure your project always uses pytest-cov version 4.0.0 exactly. Which is the best way to enforce this in your project?

A Specify 'pytest-cov==4.0.0' in your requirements.txt or pyproject.toml and use a virtual environment

B Install pytest-cov globally with pip install pytest-cov==4.0.0

C Add 'pytest-cov>=4.0.0' in your setup.cfg without a virtual environment

D Manually check plugin version before each test run and reinstall if needed

💡 Hint

Use dependency files and isolated environments for consistent versions.

Pinning the exact version in requirements.txt or pyproject.toml and using a virtual environment ensures consistent plugin versions across all developers and CI.