Use package entry points to avoid building of node builtins

[Aaronius]

When using a bundler like Vite (which does not polyfill node builtins) to build an app that has @ensdomains/address-encoder, compilation fails because @ensdomains/address-encoder depends on node's crypto module:

This can fixed by using package entry points for address-encoder to be more specific about the target environments:

https://nodejs.org/api/packages.html#package-entry-points
https://webpack.js.org/guides/package-exports/#providing-commonjs-and-esm-version-stateless

More context can be found here:

vitejs/vite#6085

[cctanfujun]

same err

[imsys]

I did some tests using the files in the lib folder:
index.js -- works
index.modern.js -- doesn't work
index.module.js -- doesn't work
index.umd.js -- works

As the package.json has:

"main": "lib/index.js",
"module": "lib/index.module.js",

Vite ends up using what is set in the module field. If we delete the module field line, it uses the main and it works.

We could also set up:

"main": "lib/index.js",
"module": "lib/index.module.js",
"types": "lib/index.d.ts",
"exports": {
  "require": "./lib/index.js",
  "import": "./lib/index.umd.js"
},

And it would use the import line. That index.module.js probably would work on node running as type:module, but UMD should probably work with that too. I would suggest to drop the module field at the root. But maybe leave the "main" for backward compatibility.

"source": "src/index.ts",
"main": "lib/index.js",
"types": "lib/index.d.ts",
"exports": {
  "node": {
    "require": "./lib/index.js",
    "import": "./lib/index.module.js"
  },
  "browser": "./lib/index.umd.js"
},

This also works, and Vite/RollUp picks what is in the "browser" field.

[imsys]

As a workaround for now, there are two options:
Point to the UMD file in Vite:

resolve:{
    alias:{
        // ↓ see https://github.com/vitejs/vite/issues/6085
        "@ensdomains/address-encoder": "@ensdomains/address-encoder/lib/index.umd.js",
    },
}

Or use a polyfill:
npm i -D crypto-browserify

resolve: {
  alias: {
    'crypto': 'crypto-browserify',
  },
}