diff options
Diffstat (limited to 'src/node_modules/es-abstract/2018/IsConcatSpreadable.js')
-rw-r--r-- | src/node_modules/es-abstract/2018/IsConcatSpreadable.js | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/src/node_modules/es-abstract/2018/IsConcatSpreadable.js b/src/node_modules/es-abstract/2018/IsConcatSpreadable.js new file mode 100644 index 0000000..dc8aae1 --- /dev/null +++ b/src/node_modules/es-abstract/2018/IsConcatSpreadable.js @@ -0,0 +1,25 @@ +'use strict'; + +var GetIntrinsic = require('../GetIntrinsic'); + +var $isConcatSpreadable = GetIntrinsic('%Symbol.isConcatSpreadable%', true); + +var Get = require('./Get'); +var IsArray = require('./IsArray'); +var ToBoolean = require('./ToBoolean'); +var Type = require('./Type'); + +// https://ecma-international.org/ecma-262/6.0/#sec-isconcatspreadable + +module.exports = function IsConcatSpreadable(O) { + if (Type(O) !== 'Object') { + return false; + } + if ($isConcatSpreadable) { + var spreadable = Get(O, $isConcatSpreadable); + if (typeof spreadable !== 'undefined') { + return ToBoolean(spreadable); + } + } + return IsArray(O); +}; |