> "matchers" [...] let you test values in different ways

Example docs for Jest's matchers: https://jestjs.io/docs/en/using-matchers

Generally speaking, if you use a specific matcher, you get a better (more informative) error message when the test fails.

Ah, the common testing functions like `assert_equal`. Thanks!

Right, and some APIs let you write your own. Getting a custom one to hand out actionable error messages is a bit tricky but quite worth it.