Define Secondary Entry Points for Typescript Packages

If you have a package where you want people to be able to access more than just the main file, you can define an exports property in the package.json file. Like this:

1{ 2 "exports": { 3 "./package.json": "./package.json", 4 ".": "./src/index.js", 5 "./foo": "./src/foo.js", 6 "./bar": "./src/bar.js" 7 } 8} 9

Then people can access code in your library through any of the provided entry points.

1import myLib from 'my-lib'; 2import foo from 'my-lib/foo'; 3import bar from 'my-lib/bar'; 4

Setup package.json export fields with Nx

Nx helps generate other properties in the package.json file, and you can also use Nx to maintain this property.

If you're using the @nx/js:tsc executor, as of Nx 16.8, you can specify the additionalEntryPoints and generateExportsField options. Here's an example:

1{ 2 "name": "my-awesome-lib", 3 "nx": { 4 "targets": { 5 "build": { 6 "executor": "@nx/js:tsc", 7 "options": { 8 "main": "packages/my-awesome-lib/src/index.ts", 9 "additionalEntryPoints": [ 10 "packages/my-awesome-lib/src/foo.ts", 11 "packages/my-awesome-lib/src/bar.ts" 12 ], 13 "generateExportsField": true 14 } 15 } 16 } 17 } 18} 19

When building the library, the @nx/js:tsc executor automatically adds the correct exports definition to the resulting package.json.

Compile to Multiple Formats

You can also compile to multiple formats, if you switch to using the @nx/rollup:rollup executor. Read all the details here.