Daniel Hiller

Rules for test driven bug fixing

2012-03-29

tdd bugfix 

Just a quick note to myself for how to do bug fixing:

1. Write an integration test that reproduces the bug
   This should create a test failure which will guard against regressions later on
2. Write integration tests for the other cases
   You should write at least one test. This should prove that it works the other way so you’ll feel safe you don’t break behavior later on
3. Track down the problem to unit level
   Debug to the lowest level where you can find the real cause of the problem
4. Write a unit test that reproduces the bug
   This should create a test failure which will guard against regressions later on
5. Write unit tests for the other cases
   You should write at least one test. There may be a chance that other corner cases have slipped as well, so examine closely. Keep in mind that unit tests are cheap!
6. Now, fix the bug
   Change it so all unit tests are green
7. Clean up
   Tidy up, don’t leave a mess.
   Remember: Someone certainly will have to come back here. If that one is you, you will spend much more time, cursing the one who left that mess than if you do it right now!
8. Run the unit tests again
   Verify your clean up didn’t break anything
9. Run the integration tests
   These should be green by now
10. Integrate changes
11. Create release

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• Using Infinitest for real
• Reasons For Developing Without Tests
• Warum ich TDD liebe