git.r.bdr.sh - rbdr/dotfiles/blob

   1 // Big thanks to @WebReflection for sorting this out
   2 // https://gist.github.com/WebReflection/5593554
   3
   4 'use strict';
   5
   6 var isObject      = require('../is-object')
   7   , value         = require('../valid-value')
   8
   9   , isPrototypeOf = Object.prototype.isPrototypeOf
  10   , defineProperty = Object.defineProperty
  11   , nullDesc = { configurable: true, enumerable: false, writable: true,
  12                 value: undefined }
  13   , validate;
  14
  15 validate = function (obj, prototype) {
  16         value(obj);
  17         if ((prototype === null) || isObject(prototype)) return obj;
  18         throw new TypeError('Prototype must be null or an object');
  19 };
  20
  21 module.exports = (function (status) {
  22         var fn, set;
  23         if (!status) return null;
  24         if (status.level === 2) {
  25                 if (status.set) {
  26                         set = status.set;
  27                         fn = function (obj, prototype) {
  28                                 set.call(validate(obj, prototype), prototype);
  29                                 return obj;
  30                         };
  31                 } else {
  32                         fn = function (obj, prototype) {
  33                                 validate(obj, prototype).__proto__ = prototype;
  34                                 return obj;
  35                         };
  36                 }
  37         } else {
  38                 fn = function self(obj, prototype) {
  39                         var isNullBase;
  40                         validate(obj, prototype);
  41                         isNullBase = isPrototypeOf.call(self.nullPolyfill, obj);
  42                         if (isNullBase) delete self.nullPolyfill.__proto__;
  43                         if (prototype === null) prototype = self.nullPolyfill;
  44                         obj.__proto__ = prototype;
  45                         if (isNullBase) defineProperty(self.nullPolyfill, '__proto__', nullDesc);
  46                         return obj;
  47                 };
  48         }
  49         return Object.defineProperty(fn, 'level', { configurable: false,
  50                 enumerable: false, writable: false, value: status.level });
  51 }((function () {
  52         var x = Object.create(null), y = {}, set
  53           , desc = Object.getOwnPropertyDescriptor(Object.prototype, '__proto__');
  54
  55         if (desc) {
  56                 try {
  57                         set = desc.set; // Opera crashes at this point
  58                         set.call(x, y);
  59                 } catch (ignore) { }
  60                 if (Object.getPrototypeOf(x) === y) return { set: set, level: 2 };
  61         }
  62
  63         x.__proto__ = y;
  64         if (Object.getPrototypeOf(x) === y) return { level: 2 };
  65
  66         x = {};
  67         x.__proto__ = y;
  68         if (Object.getPrototypeOf(x) === y) return { level: 1 };
  69
  70         return false;
  71 }())));
  72
  73 require('../create');