And take out the test results outside the code. This article is about automation and increasing the convenience of testing in Python.
Introductory
I had a project that has been under development for several years. There were no tests in the project. And also he had active dependencies on other teams, which also influenced the result.
Regression testing was one of the steps for more confident development. Its essence is in comparing the calculated data with the last canonized result of the program.
python . .
:
- . , Python xml, json . ,
textwrap.dedent. - . .
- . , . . .
, . testoot 3.4+.
. .
foo . :
def foo():
return {'a': 1}
def test_simple(testoot: Testoot):
testoot.test(foo())
pytest:
pytest -s tests
. . testoot Testoot .
:
def foo():
return {'a': 2}
def test_simple(testoot: Testoot):
testoot.test(foo())
AssertionError :
...
def test_simple(testoot: Testoot):
> testoot.test(foo()))
cls = <class 'testoot.ext.pytest.PytestComparator'>, test_obj = {'a': 2}, canon_obj = {'a': 1}
@classmethod
def compare(cls, test_obj: any, canon_obj: any):
"""Compares objects"""
> assert test_obj == canon_obj
E AssertionError
. - .
--canonize.
pytest -s tests --canonize
, pytest ( --verbose ):
tests/test_console/test_console.py [tests/test_console/test_console.py::test_simple]
{'a': 2} == {'a': 1}
~Differing items:
~{'a': 2} != {'a': 1}
~Use -v to get the full diff
Canonize [yn]? y
.
. .
. :
- pickle. Python. VCS pickle
- bytes. , .
- str. utf-8 , .
- json . json, , .
, VCS .
. .
def test_filename(testoot: Testoot):
d = Path(testoot.storage.root_dir / 'hello.json')
d.write_text('{}')
testoot.test_filename(str(d))
Testoot. :
import pytest
from testoot.ext.pytest import PytestContext
from testoot.ext.simple import DefaultBaseTestoot
from testoot.pub import AskCanonizePolicy, PickleSerializer, \
LocalDirectoryStorage, ConsoleUserInteraction, Testoot
@pytest.fixture(scope='module')
def base_testoot():
regress = DefaultBaseTestoot(
storage=LocalDirectoryStorage('.testoot'),
)
regress.storage.ensure_exists()
yield regress
@pytest.fixture(scope='function')
def testoot(base_testoot, request):
fixture = Testoot(base_testoot, PytestContext(request))
yield fixture
DefaultBaseTestoot . Testoot (scope='function'). pytest request , .
DefaultBaseTestoot BaseTestoot -: .testoot pickle-, --canonize.
-:
regress = DefaultBaseTestoot(
serializer=JsonSerializer(),
)
. pytest :
class PytestComparator(Comparator):
@classmethod
def compare(cls, test_obj: any, canon_obj: any):
"""Compares objects"""
assert test_obj == canon_obj
PytestContext(request, serializer=BinarySerializer(), comparator=PytestComparator()). :
def test_str(testoot: Testoot):
result = 'abc'
regress.test(result, serializer=StringSerializer(), comparator=PytestComparator())
, BaseTestoot.
, . , .
It may also be necessary to remove constantly changing elements from data such as the date of the last change. So that such changes do not penetrate the stored data.
Conclusion
This was an overview of the testing and features of the library for Python. I will be glad to comments and suggestions!
Installation: pip3 install testoot
Documentation: https://testoot.readthedocs.io
Source code: https://github.com/aptakhin/testoot