The differences of behaviors of `isPlainObject`

differences-of-isplainobject.md

The differences of behaviors of isPlainObject

(Node.js v0.11〜)

          PObject   PObj      lodash    @fav      
(1)       true      true      true      true      
(2)       true      true      true      true      
(3)       true      true      true      true      
(4)       true      true      true      true      
(5)       true      false     false     false     
(6)       false     false     false     false     
(7)       false     false     false     false     
(8)       false     false     false     false     
(9)       false     false     false     false     
(10)      false     false     false     false     
(11)      false     false     false     false     
(12)      false     false     false     false     
(13)      false     false     false     false     
(14)      false     false     false     false     
(15)      false     false     false     false     
(16)      false     false     false     false     
(17)      false     false     false     false     
(18)      false     false     false     false     
(19)      true      true      true      true      
(20)      true      true      true      true      
(21)      true      true      true      true      
(22)      true      true      true      true      
(23)      true      true      true      true      
(24)      false     true      true      true      
(25)      false     true      true      true      
(26)      false     true      true      true      
(27)      false     true      true      true      
(28)      false     true      true      true      
(29)      *Error*   true      true      true      
(30)      true      true      true      true      
(31)      *Error*   true      false     true      

(Node.js 〜v0.10)

          PObject   lodash    @fav      
(1)       true      true      true      
(2)       true      true      true      
(3)       true      true      true      
(4)       true      true      true      
(5)       true      false     false     
(6)       false     false     false     
(7)       false     false     false     
(8)       false     false     false     
(9)       false     false     false     
(10)      false     false     false     
(11)      false     false     false     
(12)      false     false     false     
(13)      false     false     false     
(15)      false     false     false     
(16)      false     false     false     
(17)      false     false     false     
(18)      false     false     false     
(19)      true      false     false     
(20)      true      false     false     
(21)      true      false     false     
(22)      true      false     false     
(23)      true      true      true      
(24)      false     true      true      
(25)      false     true      true      
(26)      false     true      true      
(27)      false     true      true      
(28)      false     true      true      
(29)      *Error*   true      true      
(30)      true      true      true      
(31)      *Error*   false     true      

source-code.md

'use strict';

var padRight = require('@fav/text.pad-right');

var funcs = [
  ['PObject', require('is-plain-object').isPlainObject],
  ['PObj',    require('is-plain-obj')],
  ['lodash',  require('lodash.isplainobject')],
  ['@fav',    require('@fav/type.is-plain-object')],
];

var colWidth = 10;

function header() {
  var str = funcs.map(function(fn) {
    return fn[0];
  }).reduce(function(s, r) {
    return s + padRight(r, colWidth);
  }, padRight('', colWidth));
  console.log(str);
}

function test(n, v) {
  var str = funcs.map(function(fn) {
    try {
      return fn[1](v);
    } catch (e) {
      return '*Error*';
    }
  }).reduce(function(s, r) {
    return s + padRight('' + r, colWidth);
  }, padRight('(' + n + ')', colWidth));
  console.log(str);
}


header();
test(1, {});
test(2, { foo: 'bar' });
test(3, Object.create(Object.prototype));
test(4, Object.create(null));
test(5, Object.create({}));
test(6, null);

test(7, true);
test(8, 0);
test(9, 123);
test(10, 'abc');
test(11, new Date(0));
test(12, []);
test(13, ['foo', 'bar']);
test(14, Symbol('foo'));
test(15, function() {});
test(16, function A() {});
test(17, new function() {});
test(18, new function Foo() {});

test(19, JSON.parse('{"__proto__":{}}'));
test(20, JSON.parse('{"__proto__":{"polluted":1}}'));
test(21, JSON.parse('{"__proto__":{"__proto__":{}}}'));
test(22, JSON.parse('{"__proto__":{"__proto__":{"polluted":1}}}'));
test(23, JSON.parse('{"__proto__":null}'));

test(24, JSON.parse('{"constructor":{"prototype":{}}}'));
test(25, JSON.parse('{"constructor":{"prototype":{"polluted":1}}}'));
test(26, JSON.parse('{"constructor":{"prototype":{"__proto__":{}}}}'));
test(27, JSON.parse('{"constructor":{"prototype":{"constructor":{"prototype":{"polluted":1}}}}}'));
test(28, JSON.parse('{"constructor":{"prototype":null}}'));

var a = {};
a.constructor = null;
test(29, a);

a = {};
a.__proto__ = null;
test(30, a);

a = {};
a.__proto__.constructor = null;
test(31, a);