How do you tell that your unit tests are correct?

Question

I\'ve only done minor unit testing at various points in my career. Whenever I start diving into it again, it always troubles me how to prove that my tests are correct. How

Answer 1

As above, the best way is to write the test before the actual code. Find real life examples of the code your testing also if applicable (mathematical formula or similar), and compare the unit test and expected output to that.