README.md

cresolve

This library hooks SystemJS resolve to extend it with Node.js module resolution. It also looks in UNPKG to load packages without installing them.

Custom SystemJS configuration is automatically generated in the browser. Saving it to a file allows vanilla SystemJS to load the project, so this library is only needed in development. It solves pretty much all SystemJS configuration issues.

Features

• Works in the browser, using XMLHttpRequest instead of native file IO.
• Looks for node_modules and inside, in the same places Node.js would.
• Automatic UNPKG fallback when package is not yet installed.
• Handles browser mappings in package.json files.
• Allows importing a directory when it contains index.js.
• Transpiles ES6 using TypeScript compiler (by default).
• Automatically tries .tsx if a file with .ts extension is missing.
• Generates SystemJS configuration JSON to easily eliminate dependency on this library and switch to vanilla SystemJS.

Usage

First load a Promise polyfill (if needed), SystemJS and the SystemJS -format bundle provided under dist/index-system.js for example using <script> tags.

Then import the resolver and patch SystemJS as follows:

System.import('cresolve').then(function(cresolve) {
	const resolver = new cresolve.Resolver(
		cresolve.ifExists,
		cresolve.fetch
	);

	resolver.patchSystem(System);
});

Afterwards, System.import and any import or require statements in imported code have Node.js module resolution superpowers.

To print the auto-generated configuration, use:

console.log(JSON.stringify(resolver.systemConfig, null, '\t'));

License

The MIT License

Copyright (c) 2018- BusFaster Ltd