Pytest Matchers

Test your code with vague constrains

Quick Install

With pip

pip install pytest-matchers

With poetry

poetry add pytest-matchers [--group dev]

Usage

Examples on tests/examples

from random import random
from pytest_matchers import is_number


def test_random_number():
    assert random() == is_number(min_value=0, max_value=1)

And when failing:

def test_random_number():
    assert random() == is_number(min_value=1, max_value=2)

On pytest CLI

=================================== FAILURES ===================================
______________________________ test_random_number ______________________________

    def test_random_number():
>       assert random() == is_number(min_value=1, max_value=2)
E       assert 0.9048172867693559 == To be a number between 1 and 2
E        +  where 0.9048172867693559 = random()
E        +  and   To be a number between 1 and 2 = is_number(min_value=1, max_value=2)

tests/examples/test_example.py:6: AssertionError
=========================== short test summary info ============================
FAILED tests/examples/test_example.py::test_random_number - assert 0.9048172867693559 == To be a number between 1 and 2
============================== 1 failed in 0.02s ===============================

On PyCharm

tests/examples/test_example.py:4 (test_random_number)
0.9048172867693559 != To be a number between 1 and 2

Expected :To be a number between 1 and 2
Actual   :0.9048172867693559

Matchers

• is_number
• is_string
• is_list
• is_instance
• between
• one_of
• has_attribute
• is_datetime
• is_datetime_string
• same_value
• different_value
• if_true
• if_false
• case
• is_dict
• is_strict_dict
• is_json
• is_uuid
• is_exception
• after_applying_is