كتابة اختبارات pytest الأولى

تثبيت pytest

# pip install pytest

# Run all tests
# pytest

# Run a specific file
# pytest test_math.py

دالة اختبار بسيطة

# test_math.py
def add(a, b):
    return a + b

def test_add():
    assert add(2, 3) == 5

def test_add_negative():
    assert add(-1, 1) == 0

ملفات الاختبار واكتشافها

tests/
    test_utils.py
    test_models.py
    conftest.py   # shared fixtures

تجميع الاختبارات في أصناف

class TestCalculator:
    def test_add(self):
        assert 1 + 1 == 2

    def test_multiply(self):
        assert 3 * 4 == 12

اختبار الاستثناءات

import pytest

def divide(a, b):
    if b == 0:
        raise ZeroDivisionError("cannot divide by zero")
    return a / b

def test_divide_by_zero():
    with pytest.raises(ZeroDivisionError, match="cannot divide"):
        divide(10, 0)

العَلَم -v

# pytest -v
# test_math.py::test_add PASSED
# test_math.py::test_add_negative PASSED

# Show print output too:
# pytest -v -s

تخطّي الاختبارات

import pytest, sys

@pytest.mark.skip(reason="not implemented yet")
def test_future_feature():
    assert False

@pytest.mark.skipif(sys.platform == "win32", reason="Unix only")
def test_unix_only():
    assert True

وضع علامة على الاختبارات المتوقَّع فشلها

import pytest

@pytest.mark.xfail(reason="known bug #42")
def test_buggy():
    assert 1 == 2  # will fail, but that's expected

إعادة كتابة assert

def test_list_equal():
    result = [1, 2, 4]
    expected = [1, 2, 3]
    assert result == expected
# AssertionError:
#   assert [1, 2, 4] == [1, 2, 3]
#   At index 2 diff: 4 != 3

conftest.py

# conftest.py
import pytest

@pytest.fixture
def sample_data():
    return {"key": "value"}

# Any test file in the same dir can use sample_data as a parameter

تشغيل مجموعات فرعية من الاختبارات

# Run tests containing "add"
# pytest -k "add"

# Run tests NOT containing "slow"
# pytest -k "not slow"

# Run a specific test
# pytest test_math.py::test_add

تحقق سريع

مراجعة