deep clone with customizer

deep-clone

function deepClone(source, customizer){
  const _deepClone = function (source, customizer, sourcePath) {
    // If the source isn't an Object or Array, throw an error.
    if ( !(source instanceof Object) || source instanceof Date || source instanceof String) {
      throw new Error('Only Objects or Arrays are supported.');
    }

    // Set the target data type before copying.
    var target = source instanceof Array ? [] : {};

    for (let prop in source){
      // Make sure the property isn't on the protoype
      if ( source instanceof Object && !(source instanceof Array) && !(source.hasOwnProperty(prop)) ) {
        continue;
      }

      const propValue = source[prop];
      let propPath = null;

      if (sourcePath) {
        propPath = `${sourcePath}${Array.isArray(source) ? `[${prop}]` : `.${prop}`}`;
      } else {
        propPath = Array.isArray(source) ? `[${prop}]` : prop;
      }

      // If the current property is an Array or Object, recursively clone it, else copy it's value
      if ( propValue instanceof Object && !(propValue instanceof Date) && !(propValue instanceof String) )  {
        target[prop] = _deepClone(propValue, customizer, propPath)
      } else {
        if (customizer) {
          target[prop] = customizer(propValue, propPath);
        } else {
          target[prop] = propValue;
        }
      }
    }

    return target;
  }

  return _deepClone(source, customizer, "");
}

export default deepClone;