TESTS.rst

Software tests

The Strawberry Fields test suite requires pytest, pytest-cov, pytest-randomly, and pytest-mocks for coverage reports. These can be installed via pip: :

$ pip install pytest pytest-cov pytest-randomly pytest-mock

To ensure that Strawberry Fields is working correctly after installation, the test suite can be run by navigating to the source code folder and running :

$ make test

Note that this runs all of the tests, using all available backends, in both pure and mixed modes, so can be quite slow (it should take around 1 hour to complete). Alternatively, you can run the full test suite for a particular component by running :

$ make test-[component]

where [component] should be replaced with either frontend for the Strawberry Fields frontend UI, or one of the backend <backends> you would like to test (fock, tf, or gaussian).

Pytest can accept a boolean logic string specifying exactly which tests to run, if finer control is needed. For example, to run all tests for the frontend and the Gaussian backend, as well as the Fock backend (but only for pure states), you can run: :

$ make test-"gaussian or frontend or (fock and pure)"

The above syntax also works for the make coverage command, as well as make batch-test command for running the tests in batched mode.

Individual test modules are run by invoking pytest directly from the command line: :

$ pytest tests/test_gate.py

Note

Adding tests to Strawberry Fields

The tests folder is organised into three subfolders: backend for tests that only import a Strawberry Fields backend, frontend for tests that import the Strawberry Fields UI but do not make use of a backend, and integration for tests that test integration of the frontend and backends.

When writing new tests, make sure to mark what components it tests. For a backend test, you can use the backends mark, which accepts the names of the backends:

pytest.mark.backends("fock", "gaussian")

For a frontend-only test, you can use the frontend mark:

pytest.mark.frontend