You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
50 lines
2.1 KiB
50 lines
2.1 KiB
// `Symbol.prototype.description` getter |
|
// https://tc39.github.io/ecma262/#sec-symbol.prototype.description |
|
'use strict'; |
|
var $ = require('../internals/export'); |
|
var DESCRIPTORS = require('../internals/descriptors'); |
|
var global = require('../internals/global'); |
|
var has = require('../internals/has'); |
|
var isObject = require('../internals/is-object'); |
|
var defineProperty = require('../internals/object-define-property').f; |
|
var copyConstructorProperties = require('../internals/copy-constructor-properties'); |
|
|
|
var NativeSymbol = global.Symbol; |
|
|
|
if (DESCRIPTORS && typeof NativeSymbol == 'function' && (!('description' in NativeSymbol.prototype) || |
|
// Safari 12 bug |
|
NativeSymbol().description !== undefined |
|
)) { |
|
var EmptyStringDescriptionStore = {}; |
|
// wrap Symbol constructor for correct work with undefined description |
|
var SymbolWrapper = function Symbol() { |
|
var description = arguments.length < 1 || arguments[0] === undefined ? undefined : String(arguments[0]); |
|
var result = this instanceof SymbolWrapper |
|
? new NativeSymbol(description) |
|
// in Edge 13, String(Symbol(undefined)) === 'Symbol(undefined)' |
|
: description === undefined ? NativeSymbol() : NativeSymbol(description); |
|
if (description === '') EmptyStringDescriptionStore[result] = true; |
|
return result; |
|
}; |
|
copyConstructorProperties(SymbolWrapper, NativeSymbol); |
|
var symbolPrototype = SymbolWrapper.prototype = NativeSymbol.prototype; |
|
symbolPrototype.constructor = SymbolWrapper; |
|
|
|
var symbolToString = symbolPrototype.toString; |
|
var native = String(NativeSymbol('test')) == 'Symbol(test)'; |
|
var regexp = /^Symbol\((.*)\)[^)]+$/; |
|
defineProperty(symbolPrototype, 'description', { |
|
configurable: true, |
|
get: function description() { |
|
var symbol = isObject(this) ? this.valueOf() : this; |
|
var string = symbolToString.call(symbol); |
|
if (has(EmptyStringDescriptionStore, symbol)) return ''; |
|
var desc = native ? string.slice(7, -1) : string.replace(regexp, '$1'); |
|
return desc === '' ? undefined : desc; |
|
} |
|
}); |
|
|
|
$({ global: true, forced: true }, { |
|
Symbol: SymbolWrapper |
|
}); |
|
}
|
|
|