index.js
590 Bytes
'use strict';
var strValue = String.prototype.valueOf;
var tryStringObject = function tryStringObject(value) {
try {
strValue.call(value);
return true;
} catch (e) {
return false;
}
};
var toStr = Object.prototype.toString;
var strClass = '[object String]';
var hasToStringTag = typeof Symbol === 'function' && typeof Symbol.toStringTag === 'symbol';
module.exports = function isString(value) {
if (typeof value === 'string') { return true; }
if (typeof value !== 'object') { return false; }
return hasToStringTag ? tryStringObject(value) : toStr.call(value) === strClass;
};