Skip empty types in union (build-time variant)

Author: jmini

client/model-builder/src/main/java/io/smallrye/graphql/client/model/helper/OperationModel.java

@@ -441,6 +441,9 @@ private String makeFirstLetterUppercase(String value) {
     }
 
     private String fieldsFragment(TypeModel type) {
+        if (type.fields().findAny().isEmpty()) {
+            return "";
+        }
         return "... on " + type.getGraphQlTypeName() + fields(type);
     }