to-bool/source/to-bool.js

Convert types to boolean.

(function(module) {

	"use strict";

	module.exports = function toBool(item) {
		switch(typeof item) {
			case "boolean":
				return item;
			case "function":
				return true;
			case "number":
				return item > 0 || item < 0;
			case "object":
				return !!item;
			case "string":
				item = item.toLowerCase();
				return ["true", "1"].indexOf(item) >= 0;
			case "symbol":
				return true;
			case "undefined":
				return false;

			default:
				throw new TypeError("Unrecognised type: unable to convert to boolean");
		}
	};

})(module);