dynamic-import-require

.gitignore

node_modules

a.js

require('./b.js');

b.js

// Object.assign to force same output between node master and @std/esm
import('./c.mjs').then(ns => console.log(Object.assign({}, ns)));

c.mjs

// just exports an empty namespace

package-lock.json

{
  "name": "esm-indirect-dynamic-import",
  "version": "1.0.0",
  "lockfileVersion": 1,
  "requires": true,
  "dependencies": {
    "@std/esm": {
      "version": "0.18.0",
      "resolved": "https://npm.groupondev.com:443/api/npm/npm-release/@std/esm/-/esm-0.18.0.tgz",
      "integrity": "sha1-4hK1Zcdl+Tsp7FIqSToZLOeuK6Y="
    }
  }
}

package.json

{
  "name": "esm-indirect-dynamic-import",
  "version": "1.0.0",
  "description": "",
  "main": "a.js",
  "scripts": {
    "test": "node test.js"
  },
  "repository": {
    "type": "git",
    "url": "git+ssh://git@gist.github.com/ad42a0e2e8a156670239286b5fab0807.git"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "bugs": {
    "url": "https://gist.github.com/ad42a0e2e8a156670239286b5fab0807"
  },
  "homepage": "https://gist.github.com/ad42a0e2e8a156670239286b5fab0807",
  "dependencies": {
    "@std/esm": "^0.18.0"
  }
}

test.js

'use strict';

const assert = require('assert');
const execFile = require('child_process').execFile;

function mustCall(fn) {
  let wasCalled = false;
  process.on('exit', () => {
    if (!wasCalled) throw new Error('should have called function');
  });
  return (...args) => {
    wasCalled = true;
    return fn(...args);
  };
}

execFile(process.execPath, [
  '-r', '@std/esm', 'b.js',
], {
  cwd: __dirname,
}, mustCall((err, stdout) => {
  if (err) throw err;
  assert.strictEqual('{}\n', stdout);
}));

execFile(process.execPath, [
  '-r', '@std/esm', 'a.js',
], {
  cwd: __dirname,
}, mustCall((err, stdout) => {
  if (err) throw err;
  assert.strictEqual('{}\n', stdout);
}));

For reference using latest node nightly:

> node --version
v10.0.0-nightly201712084e65f9d504

> node --experimental-modules --harmony a.js
(node:16387) ExperimentalWarning: The ESM module loader is experimental.
{}

> node --experimental-modules --harmony b.js
(node:16399) ExperimentalWarning: The ESM module loader is experimental.
{}