Category Archives: software engineering

Useful material on how to deal with slow tests in py.test, a bit buried in the docs:

From http://doc.pytest.org/en/latest/usage.html, to get a list of the slowest 10 test durations:

pytest --durations=10

From http://doc.pytest.org/en/latest/example/simple.html, to skip slow tests unless they are requested:

# content of conftest.py

import pytest
def pytest_addoption(parser):
    parser.addoption("--runslow", action="store_true",
        help="run slow tests")

# content of test_module.py
import pytest


slow = pytest.mark.skipif(
    not pytest.config.getoption("--runslow"),
    reason="need --runslow option to run"
)


def test_func_fast():
    pass


@slow
def test_func_slow():
    pass

Very convenient to know.