Create source bundles from ES Modules

Usage no npm install needed!

<script type="module">
  import agoricBundleSource from 'https://cdn.skypack.dev/@agoric/bundle-source';


Bundle Source

This package creates source bundles from ES Modules, compatible with Agoric contracts and SwingSet vats.

To bundle your sources, first do

import bundleSource from '@agoric/bundle-source';

const sourceBundleP = bundleSource(`${__dirname}/../path/to/toplevel`);

to get a promise for a source bundle, that resolves after reading the named sources and bundling them into a form that vats can load, as indicated by the moduleFormat below. Currently, the only supported module format is getExport. Note that this way of loading external modules is likely to change.

To obtain the contents of the promised sourceBundleP, once it resolves, do:

sourceBundleP.then(({moduleFormat, source, sourceMap}) => ...);

or inside an async function (and therefore outside of Jessie), do:

const { moduleFormat, source, sourceMap } = await sourceBundleP;

getExport moduleFormat

The first main moduleFormat is the "getExport" format. It generates source like:

function getExport() {
  let exports = {};
  const module = { exports };
  // CommonJS source translated from the inputs.
  return module.exports;

To evaluate it and obtain the resulting module namespace, you need to endow a require function to resolve external imports.

nestedEvaluate moduleFormat

This is logically similar to the getExport format, except that the code may additionally depend upon a nestedEvaluate(src) function to be used to evaluate submodules in the same context as the parent function.

The advantage of this format is that it helps preserve the filenames within the bundle in the event of any stack traces.

Also, the toplevel getExport(filePrefix = "/bundled-source") accepts an optional filePrefix argument (which is prepended to relative paths for the bundled files) in order to help give context to stack traces.