rollup.plugin.manifest.js

import replace from '@rollup/plugin-replace';

let manifest = {};

export const replaceManifest = () => {
  return replace({
    __MANIFEST__: () => JSON.stringify(manifest),
  });
};

export default () => ({
  name: 'Manifest Collection',
  generateBundle(_, bundles) {
    manifest = {
      ...manifest,
      ...Object.assign.apply(null, Object.entries(bundles).map(([key, bundle]) => ({
        [bundle.name]: key,
      }))),
    };
  },
});