'use strict'; var callBound = require('call-bind/callBound'); var $boolToStr = callBound('Boolean.prototype.toString'); var $toString = callBound('Object.prototype.toString'); var tryBooleanObject = function booleanBrandCheck(value) { try { $boolToStr(value); return true; } catch (e) { return false; } }; var boolClass = '[object Boolean]'; var hasToStringTag = typeof Symbol === 'function' && !!Symbol.toStringTag; module.exports = function isBoolean(value) { if (typeof value === 'boolean') { return true; } if (value === null || typeof value !== 'object') { return false; } return hasToStringTag && Symbol.toStringTag in value ? tryBooleanObject(value) : $toString(value) === boolClass; };