软件工程 - Test-Driven Development (TDD)，测试驱动开发

参考

1. https://baike.baidu.com/item/测试驱动开发/3328831?fr=aladdin
2. https://en.wikipedia.org/wiki/Test-driven_development
3. https://github.com/mjhea0/flaskr-tdd

总结

先写测试，然后写程序pass掉测试，that is 测试驱动开发。

TDD usually follows the "Red-Green-Refactor" cycle, as shown in the image above:

1. Write a test
2. Run the test (it should fail)
3. Write just enough code for the test to pass
4. Refactor code and retest, again and again (if necessary)