firefox/toolkit/components/extensions/webidl-api/test/README.md

pytest test coverage for the GenerateWebIDLBindings.py script

This directory contains tests for the GenerateWebIDLBindings.py script, which is used to parse the WebExtensions APIs schema files and generate the corresponding WebIDL definitions.

See "WebIDL WebExtensions API Bindings" section from the Firefox Developer documentation for more details about how the script is used, this README covers only how this test suite works.

Run tests

The tests part of this test suite can be executed locally using the following mach command:

mach python-test toolkit/components/extensions/webidl-api/test

Write a new test file

To add a new test file to this test suite:

• create a new python script file named as test_....py
• add the test file to the python.ini manifest
• In the new test file make sure to include:
  • copyright notes as the other test file in this directory
  • import the helper module and call its setup() method (setup makes sure to add the directory where the target script is in the python library paths and the helpers module does also enable the code coverage if the environment variable is detected):

    import helpers  # Import test helpers module.
    ...
    
    helpers.setup()
    

  • don't forget to call mozunit.main at the end of the test file:

    if __name__ == "__main__":
        mozunit.main()
    

  • add new test cases by defining new functions named as test_..., its parameter are the names of the pytest fixture functions to be passed to the test case:

    def test_something(base_schema, write_jsonschema_fixtures):
        ...
    

Create new test fixtures

All the test fixture used by this set of tests are defined in conftest.py and decorated with @pytest.fixture.

See the pytest documentation for more details about how the pytest fixture works:

• https://docs.pytest.org/en/latest/explanation/fixtures.html
• https://docs.pytest.org/en/latest/how-to/fixtures.html
• https://docs.pytest.org/en/latest/reference/fixtures.html