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@easyaspython
PyOo
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@easyaspython
Adopt-a-pytest
PyOhio 2019
Dane Hillard
Lead Web Application Developer
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@easyaspython
About me
Reasons to pytest
How to pytest
More reasons to pytest
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@easyaspython
What’s a Dane?
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@easyaspython
! Developing in Python (and Django) for ~7 years
! Web app development for ~4 years
! I do hobbies
○ Lifestyle photographer
○ Musician
○ Epicurean
○ Competitive ballroom dancer
○ Blogger
○ Author
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@easyaspython
Practices of the Python Pro
! bit.ly/the-python-pro
! Gentle intro to software design practices
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@easyaspython
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! 50+ apps
! 900+ modules
! 300+ test modules
! 2K+ tests
Before: Manual,
occasional, often broken
Now: Automated*, every
commit, not broken
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@easyaspython
What’s a pytest?
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Simpler syntax
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Fixtures
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Marks, patterns, filtering
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Durations
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Parallels for most
unittest stuff
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@easyaspython
pytest is lovely
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Retrofitting is hard
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@easyaspython
Step 0: Create a baseline
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@easyaspython
Step 1: Install pytest
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Step 1a: Install pytest-cov
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Step 2: Run pytest
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Step 3: Fix test collection
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Test discovery
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Convention unittest pytest
Ⓜ test*.py ✅
Ⓜ test_*.py ✅ ✅
Ⓜ *_test.py ✅
Ⓜ *_tests.py
Ⓒ *(unittest.TestCase) ✅ ✅
ⓜ test_* ✅ ✅
Ⓒ Test* ✅
ⓜ test_* ✅
ⓕ test_* ✅
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Option A: Rename test modules
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Option B: pytest.ini
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Step 4: Shim things
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conftest.py
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Step 5: Use pytest in new tests
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Step 6: Rewrite old tests
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Step 7: Use helpful plugins
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Step 8: Integrate with CI/CD
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Incremental
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Helpful fallbacks
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Adopt and embrace
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What else is a pytest?
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Parameterization
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Works with Jenkins
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Works with tox
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Plugin-based
architecture (pluggy)
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@easyaspython
pytest
pytest-cov
pytest-django
pytest-randomly
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Thanks
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