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.
59 lines
2.5 KiB
59 lines
2.5 KiB
// `Symbol.prototype.description` getter |
|
// https://tc39.es/ecma262/#sec-symbol.prototype.description |
|
'use strict'; |
|
var $ = require('../internals/export'); |
|
var DESCRIPTORS = require('../internals/descriptors'); |
|
var global = require('../internals/global'); |
|
var uncurryThis = require('../internals/function-uncurry-this'); |
|
var hasOwn = require('../internals/has-own-property'); |
|
var isCallable = require('../internals/is-callable'); |
|
var isPrototypeOf = require('../internals/object-is-prototype-of'); |
|
var toString = require('../internals/to-string'); |
|
var defineProperty = require('../internals/object-define-property').f; |
|
var copyConstructorProperties = require('../internals/copy-constructor-properties'); |
|
|
|
var NativeSymbol = global.Symbol; |
|
var SymbolPrototype = NativeSymbol && NativeSymbol.prototype; |
|
|
|
if (DESCRIPTORS && isCallable(NativeSymbol) && (!('description' in SymbolPrototype) || |
|
// 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 : toString(arguments[0]); |
|
var result = isPrototypeOf(SymbolPrototype, this) |
|
? 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); |
|
SymbolWrapper.prototype = SymbolPrototype; |
|
SymbolPrototype.constructor = SymbolWrapper; |
|
|
|
var NATIVE_SYMBOL = String(NativeSymbol('test')) == 'Symbol(test)'; |
|
var symbolToString = uncurryThis(SymbolPrototype.toString); |
|
var symbolValueOf = uncurryThis(SymbolPrototype.valueOf); |
|
var regexp = /^Symbol\((.*)\)[^)]+$/; |
|
var replace = uncurryThis(''.replace); |
|
var stringSlice = uncurryThis(''.slice); |
|
|
|
defineProperty(SymbolPrototype, 'description', { |
|
configurable: true, |
|
get: function description() { |
|
var symbol = symbolValueOf(this); |
|
var string = symbolToString(symbol); |
|
if (hasOwn(EmptyStringDescriptionStore, symbol)) return ''; |
|
var desc = NATIVE_SYMBOL ? stringSlice(string, 7, -1) : replace(string, regexp, '$1'); |
|
return desc === '' ? undefined : desc; |
|
} |
|
}); |
|
|
|
$({ global: true, constructor: true, forced: true }, { |
|
Symbol: SymbolWrapper |
|
}); |
|
}
|
|
|