Mini Chat App (Continued)

Today, I don't really do much. I implemented authentication and make tests about it. It's actually not that much. But I think I learn about mocking in JavaScript.

Mocking is a way to "fake" a function to make it easier to test. It likes a fire drill. The alarm goes off despite there is no fire. No one would think about burning actual building to make a fire drill unless thery are insane. Mocking is about "if it works, this thing should be called" or "That should happen after this happen". When I test, I mock the authentication detail so the test won't need to get the actual firebase authentication process. If the email is invalid, the error message should appear. If we successfully login, the page should redirect. In Python, it is in the standard library called unittest. It is called MagicMock. But, in Javascript, it is from Jest library I use for the testing.