Universal JavaScript Build and Packaging

This is a toolchain for the next phase of JavaScript development. It enables developers to write JavaScript modules in ESM that work universally across many environments (Node.js import, Node.js require, Browser, Deno, etc).

You start by just writing a standard ESM module. You'll need to include "type": "module" in your package.json, as well as a "main" entry point or an export map.

npx ipjs build

This will build a package in the dist directory that has different versions of your files compiled for different environments and a new package.json file that exposes all of these files to the correct Node.js and compiler entry points.

That's it ;)

You can also compile your tests.

npx ipjs build --tests

Note: You'll need to use "named self imports", import mymodule from "mymodule", in your tests so that we can compile different CJS versions of those tests for Node.js and the browser.

You can publish to by either running npm publish in the dist directory or using:

npx ipjs publish

Requirements

There's a few Node.js and ESM features you need to stick to using and a few you need to avoid. Some are because there just isn't a very good way to provide consistent representations and some are because we need some more explicit information about your library in order to detect the dependency tree and built it successfully.

Only use named exports in files in the package.json exports map

If you use default exports from files in the exports map:

• CJS/JSDoc+Typescript users of your module will find that tsc fails to compile as it expects a the .default property to be present on anything required from your module
• If they switch to .default to satisfy tsc, node will resolve cjs at runtime via the "require": entry from the exports map which does not have a .default so will fail
• If they switch back to no .default, running bundled cjs in the browser will also fail as it will be supplied the esm version where .default is present after all

Only export individual files in export map (no directories or pattern matching)