ESM and writing test using Jest

[chilly locust]

Hello, I'm writing some tests on my API gateway. I use the ES module, and I wanted to use Jest for testing. But configuring Jest with ESM is just hell. I can't make it work. Has someone ever used Jest with ESM and some specific configuration in tsconfig?

[drifting trellis]

@chilly locust It helps if you describe the problem you're running into rather than asking "has anyone ever done it"

[chilly locust]

Yeah, sorry, that just drives me crazy... For now, I've managed to fix some errors, but the one I face now is that on my test file, I import a lib but Jest cannot find it. It return me this:

src/infrastructure/repository/code.spec.ts:4:22 - error TS2307: Cannot find module 'postgrejs' or its corresponding type declarations.

    4 import { Pool } from 'postgrejs';

[drifting trellis]

That's a type-script error saying it can't find types... but it looks like types are built-into that module, so either 1) the module isn't installed, or 2) there's something weird in whatever tsconfig you're using for jest.

[jolly zinc]

@chilly locust Can I ask how you could manage to test TypeScript ESMs with Jest? as I understand you should change a lot for example hack the default resolver for Jest. Could I have your configration files for jest.config and tsconfig? 🙏

[drifting trellis]

@jolly zinc It's probably better to open your own help channel with details of your problem rather than asking in related help channels