This is a neat article. I do have comments about testing in general though. IME most developer do not understand each test has four possible outcomes: * Code

This is a neat article. I do have comments about testing in general though. IME most developer do not understand each test has four possible outcomes: * Code is good and test passes * Code is bad and test fails These are the only two possible outcomes developers focus on: When I ask what they should do if a test that used to pass now fails, they always tell me stories about how to debug the code under test. There are two additional possibilities in test: * Code is bad yet test passes (false negative) * Code is good yet test fails (false positive) Again, IME, most people do not look at the test again once it passes for the first time. As a result, tests which are themselves code, become the largest untested part of the code base. You get these thousands and thousands of lines of untested code yet you have 100% code coverage. Some of my blog posts on testing: * Deception in tests considered harmful https://www.nu42.com/2017/02/deception-in-tests-harmful.html https://www.nu42.com/2017/02/deception-in-tests-harmful.html * Know what you are testing: The case of the test for median in Boost.Accumulators C++ Library <https://www.nu42.com/2016/12/cpp-boost-median-test.html https://www.nu42.com/2016/12/cpp-boost-median-test.html> * Who is testing the tests? https://www.nu42.com/2015/05/who-is-testing-the-tests.html https://www.nu42.com/2015/05/who-is-testing-the-tests.html * Slashing one's feet with tests, or, how to fix 2,950 test failures in one fell swoop https://www.nu42.com/2015/08/fix-2950-test-failures.html https://www.nu42.com/2015/08/fix-2950-test-failures.html