CJS Revamp Proposal

exporter.cjs.js

"use strict";
exports.incr = incr;
var __esBindingListeners = [];

function __esBindingSet(name, value) {
  exports[name] = value;

  for (var i = 0, l = __esBindingListeners.length; i < l; i++) {
    __esBindingListeners[i](name, value);
  }
}

function __esBindingListen(callback) {
  __esBindingListeners.push(callback);
}

exports.__esBindingListen = __esBindingListen;
var count = 0;

function incr() {
  count++, __esBindingSet("count", count);
}
__esBindingSet("count", count);

exporter.es6.js

export var count = 0;

export function incr() {
  count++;
}

importer.cjs.js

"use strict";
var exporter$$ = require("./exporter"), count = exporter$$.count, incr = exporter$$.incr;

exporter$$.__esBindingListen && exporter$$.__esBindingListen(function(__esBindingName, __esBindingValue) {
  switch (__esBindingName) {
  case "count":
    count = __esBindingValue;
    break;
  case "incr":
    incr = __esBindingValue;
    break;
  }
});

assert.equal(count, 0);
incr();
assert.equal(count, 1);

importer.es6.js

import { count, incr } from './exporter';

assert.equal(count, 0);
incr();
assert.equal(count, 1);