unittestinginpythonfor-PYDevelopers.pptx

unittestinginpythonfor-PYDevelopers.pptx

• 1.
  INTRO TO UNIT TESTINGIN PYTHON
• 2.
  TESTING • Testing isfinding out how well something works. How do you test whether a new table you bought is strong enough? (revealing capabilities by putting it under strain) Now, lets look a little more into software testing…
• 3.
  WHAT ARE THEDIFFERENTTESTS? • Unit tests • Integration tests • Functional tests • Non function tests • UAT (User Acceptance) • Stress test • Regression tests And many more.. (100+ types) **We just use the first two 
• 4.
  UNIT TEST • Why? -To detect changes that may break a design contract - To reduces defects in the newly developed features - To verify the accuracy/functionality of a unit. Two popular ways to do it in python unittest pytest To write better code. • How? By testing individual units/components of the app/software. A unit is the smallest testable part of any software.
• 5.
  WHY PYTEST? • Popular •Concise • Has helpful assert messages • Powerful fixture • etc .. (Don’t ask me what more!)
• 6.
  INSTALL & SETUP •To install pytest - pip install pytest • unittest module is part of python3 • Coverage module – pip install coverage OR pip install pytest-cov • Run tests – • pytest arg1 arg2 arg3 • Run coverage – • coverage run -m pytest arg1 arg2 arg3 OR • pytest --cov=src/ tests/
• 7.
  PYTEST – TESTDISCOVERY • Collection starts from the cmd line args which maybe directories, files or test ids. • Recurse into directories • Files with *_test.py or test_*.py • Test prefixed test classes without an init method • test_ prefixed methods within them
• 8.
  PYTEST – FEWOPTIONS • -r : short test summary info and its variants, f - failed E - error s - skipped x - xfailed X - xpassed p - passed P - passed with output • Special characters for (de)selection of groups: a - all except pP A - all N - none, this can be used to display nothing (since fE is the default) • --pdb : PDB (Python Debugger) on failures
• 9.
  • setUp() -to set up initial state for all test methods • tearDown() – to clean-up after a test method runs. • setUpClass() • tearDownClass() • run() – Define the order of running the test cases • skipTest(reason) • subTest(msg=None, **params) UNITTEST - Unit testing framework Read More: https://docs.python.org/3/library/unittest.html
• 10.
  MOCKING & PATCHING •Mock and MagicMock objects create all attributes and methods as you access them and store details of how they have been used. • The patch() decorator / context manager makes it easy to mock classes or objects in a module under test.
• 11.
  FIXTURES • pytest fixturesoffer dramatic improvements over the classic xUnit style of setup/teardown functions: • fixtures have explicit names and are activated by declaring their use from test functions, modules, classes or whole projects. • fixtures are implemented in a modular manner, as each fixture name triggers a fixture function which can itself use other fixtures. • fixture management scales from simple unit to complex functional testing, allowing to parametrize fixtures and tests according to configuration and component options, or to re-use fixtures across function, class, module or whole test session scopes.
• 12.
  THANKYOU