Unpopular opinion, forget about Jest! 😔
I'm very sad to say this, because I have used it a lot in the past, and for a long time I considered it the best framework to test Node.js applications.
It suffers from serious memory leaks -> jestjs/jest#11956 This means that it is not suitable to be used with middle/big code repositories.
It doesn't fully support ESM -> jestjs/jest#9430 In the past, I was forced to transform a module in a static class simply because otherwise mocks didn't work.
The last straw is jestjs/jest#2549 Basically Jest VM differs from Node.js, but it is used to test Node.js applications. How can we consider it realiable? To prove this last point, simply clone this repo and execute:
npm run jest
and then
npm run assert and see with your own eyes that, inside Jest, a caught Error is not an instance of Error 😵.
Thanks to Matteo Collina for sharing this https://www.twitch.tv/matteocollina/clip/CleverResourcefulFennelBabyRage-oGUFchiE1SAJIApU
Jest is slower compared to other test frameworks like TAP. x
If it is up to me I won't use Jest anymore to test Node.js applications. IMO we should embrace Node.js test framework shipped starting from v18 version 🚀 👉 https://nodejs.org/docs/latest-v18.x/api/test.html