testing when module using the test suite not correctly working

lib/add.js

@@ -41,7 +41,7 @@ module.exports = function(archive, files, options) {
     })
 
     // When all is done resolve the Promise.
-    .then(function(args) {
+    .done(function(args) {
       return resolve(args);
     })
     // Catch the error and pass it to the reject function of the Promise.