TypeScript issue: `moduleResolution:NodeNext` doesn’t work with this library

[rauschma]

The problem

tsconfig.json:

"module": "NodeNext",
"moduleResolution": "NodeNext",

TypeScript code:

import { parse } from '@adobe/css-tools';

Result – error from tsc:

• Could not find a declaration file for module '@adobe/css-tools'. '~/my-lib/node_modules/@adobe/css-tools/dist/index.mjs' implicitly has an 'any' type.
  • There are types at '~/my-lib/node_modules/@adobe/css-tools/dist/types.d.ts', but this result could not be resolved when respecting package.json "exports". The '@adobe/css-tools' library may need to update its package.json or typings.

Solutions

Quickest fix – change package.json:

"exports": {
  "import": "./dist/index.mjs",
  "types": "./dist/types.d.ts",
  "require": "./dist/index.cjs"
},

In the long run, you don’t need "main", "module" and "types" (anywhere!) anymore, as these are superseded by "exports" and modern TypeScript .d.ts resolution. You only have to rename:

mv types.d.ts index.d.mts

Possibly useful

• TypeScript documentation on package "exports": https://www.typescriptlang.org/docs/handbook/modules/reference.html#packagejson-exports
• This tool was recommended to me as a linter for packages with TypeScript types (haven’t used it yet though): https://github.com/arethetypeswrong/arethetypeswrong.github.io
• I’m not sure how well .d.mts works with older TypeScript versions. There, you may have some success with the package.json property "typesVersions" (but in general it’s better if you don’t use it and only rely on "exports"): https://2ality.com/2021/06/typescript-esm-nodejs.html

[holblin]

Fixed through https://github.com/adobe/css-tools/pull/274 I will keep this issue open for the long term solution.

Thanks a lot for that detailed issue. This is very use full and well detailed. I truly appreciated.