diff options
Diffstat (limited to 'node_modules/object.assign/hasSymbols.js')
-rw-r--r-- | node_modules/object.assign/hasSymbols.js | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/node_modules/object.assign/hasSymbols.js b/node_modules/object.assign/hasSymbols.js new file mode 100644 index 000000000..f6e0db978 --- /dev/null +++ b/node_modules/object.assign/hasSymbols.js @@ -0,0 +1,41 @@ +'use strict'; + +var keys = require('object-keys'); + +module.exports = function hasSymbols() { + if (typeof Symbol !== 'function' || typeof Object.getOwnPropertySymbols !== 'function') { return false; } + if (typeof Symbol.iterator === 'symbol') { return true; } + + var obj = {}; + var sym = Symbol('test'); + var symObj = Object(sym); + if (typeof sym === 'string') { return false; } + + if (Object.prototype.toString.call(sym) !== '[object Symbol]') { return false; } + if (Object.prototype.toString.call(symObj) !== '[object Symbol]') { return false; } + + // temp disabled per https://github.com/ljharb/object.assign/issues/17 + // if (sym instanceof Symbol) { return false; } + // temp disabled per https://github.com/WebReflection/get-own-property-symbols/issues/4 + // if (!(symObj instanceof Symbol)) { return false; } + + var symVal = 42; + obj[sym] = symVal; + for (sym in obj) { return false; } + if (keys(obj).length !== 0) { return false; } + if (typeof Object.keys === 'function' && Object.keys(obj).length !== 0) { return false; } + + if (typeof Object.getOwnPropertyNames === 'function' && Object.getOwnPropertyNames(obj).length !== 0) { return false; } + + var syms = Object.getOwnPropertySymbols(obj); + if (syms.length !== 1 || syms[0] !== sym) { return false; } + + if (!Object.prototype.propertyIsEnumerable.call(obj, sym)) { return false; } + + if (typeof Object.getOwnPropertyDescriptor === 'function') { + var descriptor = Object.getOwnPropertyDescriptor(obj, sym); + if (descriptor.value !== symVal || descriptor.enumerable !== true) { return false; } + } + + return true; +}; |