To Mock or Not to Mock, That is The Question

Photo by James Harrison on Unsplash

Mocking dependencies of your code is one of the fundamental aspects of software testing. It’s a powerful method that allows developers to gain control over a certain part of your code and create an isolated environment for your test if done too much. This will make your tests less reliable and create a false sense of security, which is exactly not what we want.

The key is to be thoughtful of what you’re mocking and for what reason you’re mocking it. If you’re e.g. mocking child components in React tests just because they’re annoying, you’re actively diminishing the representativeness of your tests. This is exactly not what we want. To help you with mocking, this article will share three tips for when it makes sense to mock and how to approach mocking in your tests.

Mock Code That Is Irrelevant and Resource Heavy

If running a piece of code is not related to how the users interact with it but do require quite some overhead, it’s a perfect candidate for mocking it away. Something like expensive calculations in the background or loading an entire sidebar is not relevant for when you’re verifying whether something is working properly on the main screen.

The most important question to ask yourself is whether the code you are mocking influences the representability of…