lodash/_getRawTag.js

import Symbol from './_Symbol.js';

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

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

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

/** Built-in value references. */
const 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) {
  const isOwn = hasOwnProperty.call(value, symToStringTag);
  const tag = value[symToStringTag];
  let unmasked = false;

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

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

export default getRawTag;