simple-extend for tiny library ( extend default config / option )

simple-extend.js

function extend() {
  const target = arguments[0] || {};
  for (let i = 1; i < arguments.length; i++) {
    const source = arguments[i];
    for (const key in source) {
      if (Object.prototype.hasOwnProperty.call(source, key)) {
        target[key] = source[key];
      }
    }
  }
  return target;
}