Cannot importing using Node.js native ESM

[LinusU]

When trying to import this library with the native support for ESM that's available in Node.js 12, 14, and 16 I'm running into the following problem:

import { isPointInPolygon } from 'geolib';
         ^^^^^^^^^^^^^^^^
SyntaxError: Named export 'isPointInPolygon' not found. The requested module 'geolib' is a CommonJS module, which may not support all module.exports as named exports.
CommonJS modules can always be imported via the default export, for example using:

import pkg from 'geolib';
const { isPointInPolygon } = pkg;

    at ModuleJob._instantiate (node:internal/modules/esm/module_job:124:21)
    at async ModuleJob.run (node:internal/modules/esm/module_job:179:5)
    at async Loader.import (node:internal/modules/esm/loader:178:24)
    at async Object.loadESM (node:internal/process/esm_loader:68:5)
    at async handleMainPromise (node:internal/modules/run_main:63:12)

According to the readme it seems like this should work:

I think that the problem is that the package.json is missing the exports key which describes how the module should be loaded by the native Node.js ESM.

This is documented here: https://nodejs.org/api/packages.html#packages_package_entry_points

Basically, I think that something like this should be added:

  "exports": {
    ".": "./es/index.js"
  }

I will try this and submit a PR if it works 🚀

[LinusU]

@manuelbieh another approach would be to release a breaking change that drops CommonJS altogether. That would be my recommendation!

Many packages are moving to this since all current versions of Node.js supports ESM now 🚀

You can read about Sindres approach (which I, and many other maintainers are also using) here: https://github.com/sindresorhus/meta/discussions/15

[muuvmuuv]

It is as simple as:

1. yarn add --dev esbuild
2. Update typescript to latest version
3. Update tsconfig.json
4. yarn tsc
5. yarn esbuild dist/tsc/*.js --outdir=dist/tsc --minify --allow-overwrite
6. Remove babel/webpack etc. :) less boilerplate

tsconfig.json:

{
  "compilerOptions": {
    "target": "es2017",
    "lib": [
      "es2018",
      "dom"
    ],
    "outDir": "dist/tsc",
    "rootDir": "src/",
    "allowJs": false,
    "skipLibCheck": true,
    "esModuleInterop": true,
    "allowSyntheticDefaultImports": true,
    "strict": true,
    "forceConsistentCasingInFileNames": false,
    "declaration": true,
    "declarationDir": "dist/types",
    "module": "esnext",
    "moduleResolution": "node",
    "resolveJsonModule": true,
    "strictNullChecks": true
  },
  "include": [
    "src/**/*.ts",
    "src/**/*.d.ts"
  ],
  "exclude": [
    "node_modules",
    "**/*.test.ts"
  ]
}

[misaon]

Some update?