Issue importing @auth/core when using Jest

[ivoilic]

Environment

System:
OS: macOS 13.2.1
CPU: (12) x64 Apple M2 Pro
Memory: 302.45 MB / 32.00 GB
Shell: 5.8.1 - /bin/zsh
Binaries:
Node: 19.6.0 - ~/.nvm/versions/node/v19.6.0/bin/node
Yarn: 1.22.19 - ~/.nvm/versions/node/v19.6.0/bin/yarn
npm: 9.4.0 - ~/.nvm/versions/node/v19.6.0/bin/npm
Watchman: 4.9.0 - /usr/local/bin/watchman
Browsers:
Chrome: 110.0.5481.100
Firefox: 98.0.2
Safari: 16.3
Packages:
@auth/core: 0.5.0

Reproduction URL

https://github.com/yusukebe/jest-authjs

Describe the issue

Importing @auth/core while running Jest fails. This is not the case with other npm modules. When importing anything from @auth/core I get the following error in Jest: Cannot find module '@auth/core/providers/github' I encountered this while writing Auth.js Middlware for Hono: honojs/middleware#52

How to reproduce

Checkout this PR: honojs/middleware#52

1. yarn install
2. yarn build
3. cd packages/authjs-server
4. jest

The author of Hono also created this more cut down demo: https://github.com/yusukebe/jest-authjs

Expected behavior

When running tests with Jest imports from @auth/core should import the same as other packages

[balazsorban44]

This is because @auth/core is published as ESM only, and Jest's ESM support is a bit funky right now.

I published your reproduction with some changes, which should make it pass the tests:

https://github.com/balazsorban44/authjs-6822

Notable additions:

• https://jestjs.io/docs/configuration#extensionstotreatasesm-arraystring
• https://jestjs.io/docs/ecmascript-modules, Step 2
• https://kulshekhar.github.io/ts-jest/docs/guides/esm-support