Ahn

The presets only set the transform regex and transformer name, it doesn’t set anything else https://github.com/kulshekhar/ts-jest/blob/main/src/presets/create-jest-preset.ts And it's more for Jest because `ts-jest` doesn't control how config is merged.

You can play with the example app https://github.com/kulshekhar/ts-jest/blob/main/examples/ts-only/jest-esm.config.js because it works there.

That one Jest requires to set always:(

> Yes because that project is also still cjs. You need to add `type: "module"` in the [package.json](https://github.com/kulshekhar/ts-jest/blob/main/examples/ts-only/package.json) I found the issue. Indeed it was caused by Jest merged config....

Can you guys please provide a repo? or use this examples https://github.com/kulshekhar/ts-jest/tree/main/examples to make a reproduce scenario. Thanks.

- does this happen to `next` tag? - does this happen when using `global`? - In v29, we don’t have anything change specifically related to this, how about the combination...

@rbnayax please use `isolatedModules: true` as a workaround. Indeed there is an issue with type checking which is provided by `ts-jest`

@goums this issue is not related to v28 or v29. This issue already happened to v28 because it's related to TypeScript APIs itself which `ts-jest` didn't change in that area.

We only compile `ts` to `js` so the error you see is about Jest not giving the file to `ts-jest` to compile

Feel free to open a PR to adjust the doc:)