An alternative way to parametrize test cases.
Project description
pytest-funparam makes it easy to write parametrized tests.
Unlike pytest.mark.parametrize, pytest-funparam:
includes the failing parameter in pytest tracebacks;
enables static type checking of parameters; and
keeps parameters and assertions closer together.
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 ===============================
Markers
Mark tests by using the .marks() method of your funparam function.
import pytest
def test_addition(funparam):
@funparam
def verify_sum(a, b, expected):
assert a + b == expected
verify_sum(1, 2, 3)
verify_sum.marks(pytest.mark.skip)(2, 2, 5)
verify_sum(4, 2, 6)
$ pytest ============================= test session starts ============================== collected 3 items test_readme.py .s. [100%] ========================= 2 passed, 1 skipped in 0.01s =========================
Test IDs
Similarly, add an id to a test using the .id() method of your funparam function:
def test_addition(funparam):
@funparam
def verify_sum(a, b, expected):
assert a + b == expected
verify_sum.id("one and two")(1, 2, 3)
verify_sum.id("two and two")(2, 2, 5)
verify_sum.id("four and two")(4, 2, 6)
$ 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 ==========================
You can also use the shorthand for assigning an id. (It does the same thing as calling .id().)
def test_addition(funparam):
@funparam
def verify_sum(a, b, expected):
assert a + b == expected
verify_sum["one and two"](1, 2, 3)
verify_sum["two and two"](2, 2, 5)
verify_sum["four and two"](4, 2, 6)
$ 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 ==========================
Type Annotations
pytest-funparam has full type annotations. The funparam fixture returns a FunparamFixture object. You can import it from pytest_funparam:
import pytest
from pytest_funparam import FunparamFixture
def test_addition(funparam: FunparamFixture):
@funparam
def verify_sum(a: int, b: int , expected: int):
assert a + b == expected
# These are valid
verify_sum(1, 2, 3)
verify_sum['it accommodates ids'](2, 2, 4)
# Marks work too!
verify_sum.marks(pytest.mark.xfail)(2, 2, 9)
# This will be marked as invalid (since it's not an int)
verify_sum(1, '2', 3)
# Using id/marks will still preserve the function's typing.
verify_sum['should be an int'](1, 2, '3')
$ mypy test_readme.py:17: error: Argument 2 to "verify_sum" has incompatible type "str"; expected "int" test_readme.py:20: error: Argument 3 to "verify_sum" has incompatible type "str"; expected "int" Found 2 errors in 1 file (checked 1 source file)
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.
Project details
Release history Release notifications | RSS feed
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.
Source Distribution
Built Distribution
Hashes for pytest_funparam-0.3.0-py3-none-any.whl
Algorithm | Hash digest | |
---|---|---|
SHA256 | 75f18aaf1e1452424a68da4752e3828f37d2242d885151c51e6a036d73ecc383 |
|
MD5 | 3d47c5f5e3d31310e60d4d665d92846d |
|
BLAKE2b-256 | 76ce2685cc20555a958c9a9a35746a2de64e9112ac5c719bbd9088f472544680 |