ES6 class to stamp

class2stamp.js

import stampit from 'stampit';
import assert from 'assert';

/**
 * Get object of non-enum properties
 */
function getNonEnum(target) {
  const props = Object.getOwnPropertyNames(target);
  const enumOnly = Object.keys(target);
  let obj = {};

  props.forEach(function(key) {
    var indexInEnum = enumOnly.indexOf(key);
    if (indexInEnum === -1 && key !== 'constructor') {
      obj[key] = target[key];
    }
  });

  return obj;
}

/**
 * Get object of enum properties
 */
function getEnum(target) {
  const props = Object.keys(target);
  let obj = {};

  props.forEach(function(key) {
    obj[key] = target[key];
  });

  return obj;
}

function convertClass(Class) {
  const constructor = function() {
    Object.assign(this, new Class());
  };
  const methods = getNonEnum(Class.prototype);

  return stampit()
    .enclose(constructor)
    .methods(methods)
    .static(getEnum(Class));
}

/***************************************************/

class Foo {
  constructor() {
    this.prop = 'foo'
  }
  
  static staticProp = 'foo'
  
  method() {
    return 'foo';
  }
}

const stamp = convertClass(Foo);

assert.equal(stamp.staticProp, 'foo');
assert.equal(stamp().prop, 'foo');
assert.equal(stamp().method(), 'foo');