pytest-funparam 0.1.0

An alternative way to parametrize test cases

pytest-funparam makes it easy to write parametrized tests.

Installation

You can install “pytest-funparam” via pip from PyPI:

$ pip install pytest-funparam

Usage

Inside a test function, decorate a function with the funparam fixture:

def test_addition(funparam):
    @funparam
    def verify_sum(a, b, expected):
        assert a + b == expected

    verify_sum(1, 2, 3)
    verify_sum(2, 2, 5)  # OOPS!
    verify_sum(4, 2, 6)

And run pytest:

$ pytest
============================= test session starts ==============================
collected 3 items

test_readme.py .F.                                                       [100%]

=================================== FAILURES ===================================
_______________________________ test_addition[1] _______________________________

    def test_addition(funparam):
        @funparam
        def verify_sum(a, b, expected):
            assert a + b == expected

        verify_sum(1, 2, 3)
>       verify_sum(2, 2, 5)  # OOPS!

test_readme.py:7:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

a = 2, b = 2, expected = 5

    @funparam
    def verify_sum(a, b, expected):
>       assert a + b == expected
E       assert (2 + 2) == 5

test_readme.py:4: AssertionError
========================= 1 failed, 2 passed in 0.03s ==========================

The test_addition test case was split into 3 tests, one for each verify_sum call.

Because funparam is parametrizing the test calls, it even works with commands like pytest --last-failed:

$ pytest --last-failed
============================= test session starts ==============================
collected 1 item

test_readme.py F                                                         [100%]

=================================== FAILURES ===================================
_______________________________ test_addition[1] _______________________________

    def test_addition(funparam):
        @funparam
        def verify_sum(a, b, expected):
            assert a + b == expected

        verify_sum(1, 2, 3)
>       verify_sum(2, 2, 5)  # OOPS!

test_readme.py:7:
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

a = 2, b = 2, expected = 5

    @funparam
    def verify_sum(a, b, expected):
>       assert a + b == expected
E       assert (2 + 2) == 5

test_readme.py:4: AssertionError
============================== 1 failed in 0.01s ===============================

Mark tests by using the _marks keyword argument on calls to verify:

import pytest

def test_addition(funparam):
    @funparam
    def verify_sum(a, b, expected):
        assert a + b == expected

    verify_sum(1, 2, 3)
    verify_sum(2, 2, 5, _marks=pytest.mark.skip)
    verify_sum(4, 2, 6)

$ pytest
============================= test session starts ==============================
collected 3 items

test_readme.py .s.                                                       [100%]

========================= 2 passed, 1 skipped in 0.01s =========================

Note that the _marks keyword argument is passed through directly to the marks keyword argument of pytest.mark.param(). This means the value can be either a single mark or a collection of marks.

Similarly, add an id to a test using the _id keyword argument:

def test_addition(funparam):
    @funparam
    def verify_sum(a, b, expected):
        assert a + b == expected

    verify_sum(1, 2, 3, _id="one and two")
    verify_sum(2, 2, 5, _id="two and two")
    verify_sum(4, 2, 6, _id="four and two")

$ pytest --collect-only
============================= test session starts ==============================
collected 3 items

<Module test_readme.py>
  <Function test_addition[one and two]>
  <Function test_addition[two and two]>
  <Function test_addition[four and two]>

========================== 3 tests collected in 0.01s ==========================

License

Distributed under the terms of the MIT license, “pytest-funparam” is free and open source software

Issues

If you encounter any problems, please file an issue along with a detailed description.