Files
lodash/lodash.isplainobject/index.js
John-David Dalton a9140d2c8f Bump to v4.0.2.
2018-02-03 19:13:37 -08:00

122 lines
3.1 KiB
JavaScript

/**
* lodash 4.0.2 (Custom Build) <https://lodash.com/>
* Build: `lodash modularize exports="npm" -o ./`
* Copyright 2012-2016 The Dojo Foundation <http://dojofoundation.org/>
* Based on Underscore.js 1.8.3 <http://underscorejs.org/LICENSE>
* Copyright 2009-2016 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
* Available under MIT license <https://lodash.com/license>
*/
/** `Object#toString` result references. */
var objectTag = '[object Object]';
/**
* Checks if `value` is a host object in IE < 9.
*
* @private
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is a host object, else `false`.
*/
function isHostObject(value) {
// Many host objects are `Object` objects that can coerce to strings
// despite having improperly defined `toString` methods.
var result = false;
if (value != null && typeof value.toString != 'function') {
try {
result = !!(value + '');
} catch (e) {}
}
return result;
}
/** Used for built-in method references. */
var objectProto = Object.prototype;
/** Used to resolve the decompiled source of functions. */
var funcToString = Function.prototype.toString;
/** Used to infer the `Object` constructor. */
var objectCtorString = funcToString.call(Object);
/**
* Used to resolve the [`toStringTag`](http://ecma-international.org/ecma-262/6.0/#sec-object.prototype.tostring)
* of values.
*/
var objectToString = objectProto.toString;
/** Built-in value references. */
var getPrototypeOf = Object.getPrototypeOf;
/**
* Checks if `value` is object-like. A value is object-like if it's not `null`
* and has a `typeof` result of "object".
*
* @static
* @memberOf _
* @category Lang
* @param {*} value The value to check.
* @returns {boolean} Returns `true` if `value` is object-like, else `false`.
* @example
*
* _.isObjectLike({});
* // => true
*
* _.isObjectLike([1, 2, 3]);
* // => true
*
* _.isObjectLike(_.noop);
* // => false
*
* _.isObjectLike(null);
* // => false
*/
function isObjectLike(value) {
return !!value && typeof value == '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 _
* @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) ||
objectToString.call(value) != objectTag || isHostObject(value)) {
return false;
}
var proto = objectProto;
if (typeof value.constructor == 'function') {
proto = getPrototypeOf(value);
}
if (proto === null) {
return true;
}
var Ctor = proto.constructor;
return (typeof Ctor == 'function' &&
Ctor instanceof Ctor && funcToString.call(Ctor) == objectCtorString);
}
module.exports = isPlainObject;