Function mock_timing

testing/conftest.py:182–216

Mocks _pytest.timing with a known object that can be used to control timing in tests deterministically. pytest itself should always use functions from `_pytest.timing` instead of `time` directly. This then allows us more control over time during testing, if testing code also uses `

(monkeypatch: MonkeyPatch)

@pytest.fixture
def mock_timing(monkeypatch: MonkeyPatch):
    """Mocks _pytest.timing with a known object that can be used to control timing in tests
    deterministically.

    pytest itself should always use functions from `_pytest.timing` instead of `time` directly.

    This then allows us more control over time during testing, if testing code also
    uses `_pytest.timing` functions.

    Time is static, and only advances through `sleep` calls, thus tests might sleep over large
    numbers and obtain accurate time() calls at the end, making tests reliable and instant.
    """
    import attr

    @attr.s
    class MockTiming:

        _current_time = attr.ib(default=1590150050.0)

        def sleep(self, seconds):
            self._current_time += seconds

        def time(self):
            return self._current_time

        def patch(self):
            from _pytest import timing

            monkeypatch.setattr(timing, "sleep", self.sleep)
            monkeypatch.setattr(timing, "time", self.time)
            monkeypatch.setattr(timing, "perf_counter", self.time)

    result = MockTiming()
    result.patch()
    return result