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node_modules/lodash/isPlainObject.js 1.61 KB
aaac7fed   liuqimichale   add
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  var baseGetTag = require('./_baseGetTag'),
      getPrototype = require('./_getPrototype'),
      isObjectLike = require('./isObjectLike');
  
  /** `Object#toString` result references. */
  var objectTag = '[object Object]';
  
  /** Used for built-in method references. */
  var funcProto = Function.prototype,
      objectProto = Object.prototype;
  
  /** Used to resolve the decompiled source of functions. */
  var funcToString = funcProto.toString;
  
  /** Used to check objects for own properties. */
  var hasOwnProperty = objectProto.hasOwnProperty;
  
  /** Used to infer the `Object` constructor. */
  var objectCtorString = funcToString.call(Object);
  
  /**
   * Checks if `value` is a plain object, that is, an object created by the
   * `Object` constructor or one with a `[[Prototype]]` of `null`.
   *
   * @static
   * @memberOf _
   * @since 0.8.0
   * @category Lang
   * @param {*} value The value to check.
   * @returns {boolean} Returns `true` if `value` is a plain object, else `false`.
   * @example
   *
   * function Foo() {
   *   this.a = 1;
   * }
   *
   * _.isPlainObject(new Foo);
   * // => false
   *
   * _.isPlainObject([1, 2, 3]);
   * // => false
   *
   * _.isPlainObject({ 'x': 0, 'y': 0 });
   * // => true
   *
   * _.isPlainObject(Object.create(null));
   * // => true
   */
  function isPlainObject(value) {
    if (!isObjectLike(value) || baseGetTag(value) != objectTag) {
      return false;
    }
    var proto = getPrototype(value);
    if (proto === null) {
      return true;
    }
    var Ctor = hasOwnProperty.call(proto, 'constructor') && proto.constructor;
    return typeof Ctor == 'function' && Ctor instanceof Ctor &&
      funcToString.call(Ctor) == objectCtorString;
  }
  
  module.exports = isPlainObject;