chomp script to auto generate export map

chompfile.toml

version = 0.1
default-task = 'build'

extensions = ['chomp@0.1:swc', 'chomp@0.1:jspm', 'chomp@0.1:npm']

[template-options.npm]
auto-install = true


[[task]]
name = 'generate-exportmap'
deps = ['package.json', 'npm:install']
invalidation = 'always'
engine = 'node'
run = '''
   import './exportmap-generator.js';
'''

exportmap-generator.js

import { Generator } from "@jspm/generator";
import { readFile, writeFile } from "fs/promises";
import mkdirp from "mkdirp";
import { dirname, parse } from "path";

mkdirp.sync(dirname(process.env.TARGET));

const { dir: CURRENT_DIRECTORY } = parse(import.meta.url);

const OUTPUT_DIR = "lib";
const DEST_PREFIX = `${CURRENT_DIRECTORY}/${OUTPUT_DIR}`;

const packageJSON = await readFile("package.json", "utf-8");
const parsedPackageJSON = JSON.parse(packageJSON);
const { exports } = parsedPackageJSON;

const generator = new Generator({
  env: ["browser", "production"],
});

const dependencyMap = await generator.traceInstall("@jspm/packages");

const { staticDeps, dynamicDeps } = dependencyMap;

[...staticDeps, ...dynamicDeps].filter((dependency) =>
  dependency.startsWith(CURRENT_DIRECTORY)
).sort().forEach((dependency) => {
  const { ext } = parse(dependency);

  const modulePath = dependency.replace(CURRENT_DIRECTORY, ".");
  const subpath = dependency.replace(DEST_PREFIX, ".");
  const exportPath = subpath.slice(0, subpath.length - ext.length);

  exports[exportPath] = {
    ...exports[exportPath],
    "browser": modulePath,
  };
});

const sortedExports = {};

Object.keys(exports).sort().forEach((key) => {
  sortedExports[key] = exports[key];
});

await writeFile(
  'package.json',
  JSON.stringify({ ...parsedPackageJSON, exports: sortedExports }, null, 2),
);

uses

• Chomp https://chompbuild.com/
• JSPM Generator https://github.com/jspm/generator