Running pynxtools Tests in Parallel

The pytest framework allows tests to run in sequential and parallel using third-party plugins such as pytest-xdist. In our pytest setup for pynxtools, we use pytest-xdist to execute tests in parallel. To handle shared resources among multiple tests, tests are grouped using the @pytest.mark.xdist_group fixture. This prevents classic race conditions by ensuring that tests sharing the same resources are executed sequentially.

Running Tests Sequentially

In a local setup, tests can be run sequentially using the following command:

$ python -m pytest tests

This will execute all tests in a sequential manner. For more details, refer to the official documentation: How to invoke pytest.

Running Tests in Parallel

The pytest-xdist plugin can be used to speed up test execution by distributing tests among available workers. To prevent race conditions, tests that share the same resources are grouped using the @pytest.mark.xdist_group(name="group_name") fixture. These grouped tests must be run with the --dist loadgroup flag. For example:

$ python -m pytest tests -n auto --dist loadgroup

Here: - The -n auto flag tells pytest to automatically distribute tests among all available workers. - The --dist loadgroup flag ensures that tests marked with the same @pytest.mark.xdist_group(name="...") are executed serially.

This setup allows for efficient parallel test execution while maintaining the integrity of tests that depend on shared resources.