Update thrown behaviour

Author: simonepri

README.md

@@ -109,7 +109,6 @@ Type: `string`
 Default: `undefined`
 
 The type of error that the object should be instance of.
-If undefined it just checks if the object is instance of Error.
 
 ## Authors
 * **Simone Primarosa** - [simonepri](https://github.com/simonepri)

index.js

@@ -37,13 +37,10 @@ function throwError(type, msg, errno, ...debug) {
  * @returns  {boolean} true if the type match, false otherwise
  */
 function errorThrown(err, type) {
-	if (type !== undefined) {
-		if (errorExist(type)) {
-			return err instanceof errors[type];
-		}
-		return false;
+	if (errorExist(type)) {
+		return err instanceof errors[type];
 	}
-	return err instanceof Error;
+	return false;
 }
 
 module.exports = {