Mock out dependencies while testing in Python

Transcript

1. Mock Out External Dependencies Rain Wu
2. Agenda Why isolate dependencies during testing The scope of patched object The potential risks of mocking dependencies with mock package The tricks of MagickMock
3. Why isolate dependencies during testing The essence of the test Tragedies while testing without isolation When should I mock?
4. foo.py test_foo.py
5. foo.py test_foo.py Function Test Determines Reflect
6. foo.py test_foo.py Execute the logic Check the result Call Return
8. Sometimes you should not really execute the logic during the test
9. Otherwise… Paid for your API calls Got banned because high-frequency access Pollute the storage Execute unrecoverable operations
10. Lab 01 How py te st po ll u te your s to rage while unit- te s ti ng?
12. The scope of patched object Context manager Function decorator Class decorator Construct and destruct manually (not recommend)
13. Lab 02 - 1 Con te xt manager
14. Lab 02 - 2 Func ti on decora to r
15. Lab 02 - 3 Class decora to r
16. Construct and Destruct Manually
17. The Potential Risks of Mocking Dependencies Wrong parameters Misspelling methods
18. Lab 03 - 1 Th e unit te st was passed accidenta ll y (but maybe you th ink th at it should be like th is )
19. Lab 03 - 2 In some cases, mock wi ll catch th e issues for you au to ma ti ca ll y
20. Lab 03 - 3 But some ti mes it won’t, so we had be tt er make th e schema of patched object s tr ic te r by ourselves
21. The Tricks of MagicMock Object attributes
22. Lab 04 - 1 Th e valid a tt ribu te s of a MagicMock object
23. Lab 04 - 2 Apply th e fi xed a tt ribu te s recursively via th e au to spec kwarg
24. Thanks