Move types from DefinitivelyTyped to here 🙇🏽‍♂️

Summary 💭

We’ve been maintaining the types for this library on DefinitivelyTyped. It’s been working ok so far as there was no interest in moving the source code to TS to get the types automatically generated.

However, it’s challenging 🧯 to keep the types up to date, given they live in a separate repository and rely on updates from contributors. After speaking with @balazsorban44, we think we can spike to move the types to a folder here (types/), get them linted through dtslint and integrated with the build pipeline 🎊

Tasks ✅

• Move types to this repo, to a folder called types in the root (suggestions welcome)
• Add dtslint and add a command to lint the types
  • add it to the CI
• Modify package.json to declare types for the package
• Modify build script to get types into /dist (suggestions welcome)
• Make a beta release and verify everything works correctly
• Update the README and website to explain types are now part of the next-auth package
• Test whether the new types take precedence over @types/next-auth
• fix typos
• Sort-out module augmentation issues
• Deprecate @types/next-auth
• Release new types on next-auth

Additional context 📓

@JuanM04 @euxn23, you’ve been actively maintaining the types in DefitnivelyTyped. Would you be interested in joining/supporting this effort? (any other contributors welcome 💚)

( cc. @iaincollins )

• Current type definitions on DefinitivelyTyped (what you get when installing @types/next-auth)
• dtslint

[lluia]

@JuanM04 super 💯 , if you make PR and merge on beta, can you then update the ✅ on this issue accordingly? In this way we can keep track on where we’re at in the migration 🙇🏽‍♂️

[balazsorban44]

Added the beta branch https://github.com/nextauthjs/next-auth/tree/beta, it can now be targeted in PRs, and once they are merged, they will automatically be released to the next-auth@beta channel on npm 🤞