lodash/_getRawTag.js

define(['./_Symbol'], function(Symbol) {

  /** Used as a safe reference for `undefined` in pre-ES5 environments. */
  var undefined;

  /** Used for built-in method references. */
  var objectProto = Object.prototype;

  /** Used to check objects for own properties. */
  var hasOwnProperty = objectProto.hasOwnProperty;

  /**
   * Used to resolve the
   * [`toStringTag`](http://ecma-international.org/ecma-262/7.0/#sec-object.prototype.tostring)
   * of values.
   */
  var nativeObjectToString = objectProto.toString;

  /** Built-in value references. */
  var symToStringTag = Symbol ? Symbol.toStringTag : undefined;

  /**
   * A specialized version of `baseGetTag` which ignores `Symbol.toStringTag` values.
   *
   * @private
   * @param {*} value The value to query.
   * @returns {string} Returns the raw `toStringTag`.
   */
  function getRawTag(value) {
    var isOwn = hasOwnProperty.call(value, symToStringTag),
        tag = value[symToStringTag];

    try {
      value[symToStringTag] = undefined;
      var unmasked = true;
    } catch (e) {}

    var result = nativeObjectToString.call(value);
    if (unmasked) {
      if (isOwn) {
        value[symToStringTag] = tag;
      } else {
        delete value[symToStringTag];
      }
    }
    return result;
  }

  return getRawTag;
});