Add unit tests for iam_user_name validator (cloudtools#529)

tests/test_validators.py

@@ -4,7 +4,7 @@
 from troposphere.validators import positive_integer, network_port
 from troposphere.validators import s3_bucket_name, encoding, status
 from troposphere.validators import iam_path, iam_names, iam_role_name
-from troposphere.validators import iam_group_name
+from troposphere.validators import iam_group_name, iam_user_name
 
 
 class TestValidators(unittest.TestCase):
@@ -115,5 +115,12 @@ def test_iam_group_name(self):
             with self.assertRaises(ValueError):
                 iam_group_name(s)
 
+    def test_iam_user_name(self):
+        for s in ['a', 'a'*64, 'A', 'Aa', 'A=,.@-']:
+            iam_user_name(s)
+        for s in ['', 'a'*65, 'a%', 'a#', 'A a']:
+            with self.assertRaises(ValueError):
+                iam_user_name(s)
+
 if __name__ == '__main__':
     unittest.main()

troposphere/validators.py

@@ -96,6 +96,10 @@ def iam_names(b):
 
 
 def iam_user_name(user_name):
+    if not user_name:
+        raise ValueError(
+            "AWS::IAM::User property 'UserName' may not be empty")
+
     if len(user_name) > 64:
         raise ValueError(
             "AWS::IAM::User property 'UserName' may not exceed 64 characters")