Added unit tests for invalid types in User-Id validation. (#90)

Author: mfahadahmed

packages/optimizely-sdk/lib/utils/user_id_validator/index.tests.js

@@ -1,5 +1,5 @@
 /**
- * Copyright 2016, Optimizely
+ * Copyright 2016, 2018, Optimizely
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -45,6 +45,20 @@ describe('lib/utils/user_id_validator', function() {
           userIdValidator.validate('');
         }, sprintf(ERROR_MESSAGES.INVALID_USER_ID, 'USER_ID_VALIDATOR'));
       });
+
+      it('should throw an error if userId is not a string', function() {
+        assert.throws(function() {
+          userIdValidator.validate(3);
+        }, sprintf(ERROR_MESSAGES.INVALID_USER_ID, 'USER_ID_VALIDATOR'));
+
+        assert.throws(function() {
+          userIdValidator.validate(true);
+        }, sprintf(ERROR_MESSAGES.INVALID_USER_ID, 'USER_ID_VALIDATOR'));
+
+        assert.throws(function() {
+          userIdValidator.validate([]);
+        }, sprintf(ERROR_MESSAGES.INVALID_USER_ID, 'USER_ID_VALIDATOR'));
+      });
     });
   });
 });