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Testing DeviceHelper with PyTest
Level beginner
Repo https://github.com/NetAutLabs/python_pytest_device_helper
Discussion Discussion GitHub Repo
Codespaces GitHub Codespaces

Lab Goal

The goal of this lab is to learn and understand the differences between three testing approaches: "monkey patching", using pytest-mock, and creating "fake objects". You will work on a Python project with five test files, but only the three mentioned below contain TODOs that need fixing.

Objectives

  1. Monkey Patching:

    • Explore how to dynamically modify or replace methods and attributes in your code during runtime.
    • Complete the TODOs in tests/test_device_helper_01_monkeypatch.py.

  2. pytest-mock:

    • Learn how to use the pytest-mock library to create and manage mock objects.
    • Discover how mocking can help isolate the code under test and verify interactions.
    • Complete the TODOs in tests/test_device_helper_02_mock.py.

  3. Fake Objects:

    • Implement fake objects that provide simplified, yet working, implementations of dependencies.
    • Recognize when and why to use fake objects over mocks or monkey patching.
    • Complete the TODOs in tests/test_device_helper_03_fakedevice.py.

Additional Information:

  • The test files are located in the tests directory, but only tests/test_device_helper_01_monkeypatch.py, tests/test_device_helper_02_mock.py, and tests/test_device_helper_03_fakedevice.py contain TODOs that require your attention.
  • These tests are marked with xfail to indicate that they are expected to fail. After you implement the necessary changes, remove the xfail markers.

  • To run and check the tests, use the following command: 

    python3 -m pytest

  • Test execution needs to be under one second.