javascriptnode.jstypescriptnpm

How can I use "exports" in package.json for nested submodules and TypeScript?

I want to take advantage of the new-ish "exports" feature of Node.js/package.json so that I can do the following:

"exports": {
  ".": "./dist/index.js",
  "./foo": "./dist/path/to/foo.js"
}

and users can do the following:

import { foo } from 'my-package/foo';

TypeScript 4.5 should support the "exports" field, yet it does not seem to work. I am building a simple package using TS 4.5.2, and I am consuming that package in a project using TS 4.5.2. I have looked at other SO questions and this GitHub thread and this bug report but can't seem to find a consensus on the issue and whether it should work today.

I am still able to import using the more verbose syntax:

import { foo } from 'my-package/dist/path/to/foo.js';

I have also tried the object notation for exports, to no avail:

"exports": {
  ".": { "require": "./dist/index.js", "import": "./dist/index.js" },
  "./foo": { "require": "./dist/path/to/foo.js", "import": "./dist/path/to/foo.js" }
}

Is this feature ready to be used with TypeScript projects today? If yes, what am I missing? Specifics about tsconfig would be useful for both the source project and consuming project. The TS compiler complains about node12/nodenext being used for either the module or moduleResolution fields (I am definitely using TS 4.5.2).

Solution

  • Here's the breakdown:

    So, if you have a TypeScript project and you want to be able to import a package which uses package.json "exports", you will need to do the following: