fix users tests (account tests still fail)

tests/js/user-tests.js

@@ -123,13 +123,20 @@ module.exports = {
 
   testRegisterExistingUser() {
     var username = uuid();
-    return callbackTest((callback) => Realm.Sync.User.register('http://localhost:9080', username, 'password', callback), (error, user) => {
-      failOnError(error);
-      assertIsUser(user);
-
+    return new Promise((resolve, reject) => {
       Realm.Sync.User.register('http://localhost:9080', username, 'password', (error, user) => {
-        assertIsAuthError(error, 611, "The provided credentials are invalid or a user already exists.");
-        TestCase.assertUndefined(user);
+        failOnError(error);
+        assertIsUser(user);
+
+        Realm.Sync.User.register('http://localhost:9080', username, 'password', (error, user) => {
+         try { 
+            assertIsAuthError(error, 613, "The account cannot be registered as it exists already.");
+            TestCase.assertUndefined(user);
+            resolve();
+          } catch(e) { 
+           reject(e);
+          }
+        });
       });
     });
   },
@@ -202,7 +209,7 @@ module.exports = {
 
   testLoginNonExistingUser() {
     return callbackTest((callback) => Realm.Sync.User.login('http://localhost:9080', 'does_not', 'exist', callback), (error, user) => {
-      assertIsAuthError(error, 611, "The provided credentials are invalid or a user already exists.");
+      assertIsAuthError(error, 611, "The provided credentials are invalid.");
       TestCase.assertUndefined(user);
     });
   },
@@ -359,7 +366,12 @@ module.exports = {
             reject("Retrieving not existing account should fail");
           })
           .catch(e => {
-            TestCase.assertEqual(e.code, 404);
+            try {
+              TestCase.assertEqual(e.code, 404);
+            }
+            catch (e) {
+              reject(e);
+            }
             resolve()
           });
       })