Could not find a declaration file for module 'next-test-api-route-handler'.

[jakejones2]

The problem

Hi! The import import { testApiHandler } from "next-test-api-route-handler"; gives me the following typescript error:

Could not find a declaration file for module 'next-test-api-route-handler'. '/Users/jakejones/Documents/repos/git/next-test-api-route-handler-import/node_modules/next-test-api-route-handler/dist/esm/index.mjs' implicitly has an 'any' type.
  There are types at '/Users/jakejones/Documents/repos/git/next-test-api-route-handler-import/node_modules/next-test-api-route-handler/dist/types/src/index.d.ts', but this result could not be resolved when respecting package.json "exports". The 'next-test-api-route-handler' library may need to update its package.json or typings.ts(7016)

I think the issue is related to prs such as:

• docs: add types to default exports unjs/unbuild#226
• Add the types condition to the package.json#exports gxmari007/vite-plugin-eslint#60

Reproduction steps

For basic reproduction: https://github.com/jakejones2/next-test-api-route-handler-import

Suggested solution

A quick fix seems to be changing package.json as follows:

"exports": {
    ".": {
      "types": "./dist/types/src/index.d.ts",
      "import": "./dist/esm/index.mjs",
      "require": "./dist/index.js",
      "default": "./dist/index.js"
    },
    "./package": "./package.json",
    "./package.json": "./package.json"
  },

However, looking at similar pull requests, the problem might require an index.d.mts file. Something like this:

"exports": {
  ".": {
    "import": {
      "types": "./dist/types/src/index.d.mts",
      "default": "./dist/esm/index.mjs",
    },
    "require": {
      "types": "./dist/types/src/index.d.ts",
      "default": "./dist/index.js",
    }
  },
  "./package": "./package.json",
  "./package.json": "./package.json"
},

Additional context

node v.20.4.0
npm v.9.7.2

[Xunnamius]

Thanks for this and especially the suggested solutions. Coincidentally, I was checking NTARH on arethetypeswrong a few days ago and pondering solutions.

I'll address this sooner than planned since this is causing problems in the wild. I haven't make the leap to node16 resolution in my TS stack yet, which let this slip under the radar. I'll have to update a few other projects as well 😄

[jakejones2]

No problem - thanks for picking this up so fast! Seems to be a common issue so hopefully not too much trouble. Best of luck with it!

[Xunnamius]

🎉 This issue has been resolved in version 4.0.0-canary.2 🎉

The release is available on:

• npm package (@canary dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[Xunnamius]

🎉 This issue has been resolved in version 3.1.10 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀