Add extra related test cases for #11

Author: boukeversteegh

betterproto/tests/inputs/casing_message_field_uppercase/casing_message_field_uppercase.json

@@ -1,3 +1,5 @@
 {
-  "UPPERCASE": 10
+  "UPPERCASE": 10,
+  "UPPERCASE_V2": 10,
+  "UPPER_CAMEL_CASE": 10
 }

betterproto/tests/inputs/casing_message_field_uppercase/casing_message_field_uppercase.proto

@@ -1,5 +1,7 @@
 syntax = "proto3";
 
 message Test {
-  int32 UPPER_CAMEL_CASE = 1;
+  int32 UPPERCASE = 1;
+  int32 UPPERCASE_V2 = 2;
+  int32 UPPER_CAMEL_CASE = 3;
 }

betterproto/tests/inputs/casing_message_field_uppercase/casing_message_field_uppercase.py

@@ -5,6 +5,12 @@
 
 def test_message_casing():
     message = Test()
+    assert hasattr(
+        message, "uppercase"
+    ), "UPPERCASE attribute is converted to 'uppercase' in python"
+    assert hasattr(
+        message, "uppercase_v2"
+    ), "UPPERCASE_V2 attribute is converted to 'uppercase_v2' in python"
     assert hasattr(
         message, "upper_camel_case"
     ), "UPPER_CAMEL_CASE attribute is converted to upper_camel_case in python"