Jest is my go-to testing framework, it's the default in many of tools I use at work in my side projects and I didn't bother to reconfigure NestJS or NX.dev before I start a new project. Jest works for me, and works well.

But sometimes... Sometimes... I have to Google a little bit harder before I figure out how to do things.

In this blog I will share some of the tricks I learned, and some of the concepts I didn't know which led me to a frustrating debugging sessions. For example, the fact that jest.mock is hoisted, which makes using variables in mocked modules a bit tricky.

This blog will be updated each time I remember some of the tricks, or I learn something new about Jest.