The Composition of a Test

Now that we have an understanding of the Jest setup, we can learn how to write a test.

In layman’s terms

Simply put, a test does exactly one thing. A test tells us whether Y is true if we’re given X. X can be an argument passed to a function, an API response, a state, or a sequence of user behaviors, while Y can be a return value, the calling of a function, presence in the DOM, an error, etc.

Another ...