Do your tests fail?

Posting this mainly as a reminder to myself.

It’s probably not enough to write a unit test, check that it passes, and continue on with your day. You should also check that it can fail too. Make it expect something that’s slightly different from what you really want and see if it blows up in your face.

Otherwise, you might’ve just written the unit test equivalent of a yes-man and it won’t really provide any value for you or your meticulously-crafted test suite.