Add unit tests for TruncateError message handling

Co-authored-by: mykaul <4655593+mykaul@users.noreply.github.com>

Author: Copilot

tests/unit/test_truncate_error.py

@@ -0,0 +1,59 @@
+# Copyright ScyllaDB, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import unittest
+from cassandra.protocol import TruncateError
+
+
+class TruncateErrorTest(unittest.TestCase):
+    """
+    Test TruncateError exception behavior
+    """
+
+    def test_truncate_error_message_includes_server_message(self):
+        """
+        Verify that TruncateError includes the server-provided error message
+        in addition to the generic summary.
+        
+        This addresses the issue where the error message was thought to be ignored.
+        The server message should always be included in the error string representation.
+        """
+        server_message = "unconfigured table test_table"
+        error = TruncateError(code=0x1003, message=server_message, info=None)
+        error_str = str(error)
+        
+        # Verify both the summary and server message are in the error string
+        self.assertIn("Error during truncate", error_str, 
+                     "Generic summary should be in error string")
+        self.assertIn(server_message, error_str,
+                     "Server-provided message should be in error string")
+        
+    def test_truncate_error_code(self):
+        """
+        Verify that TruncateError has the correct error code (0x1003)
+        """
+        error = TruncateError(code=0x1003, message="test", info=None)
+        self.assertEqual(error.code, 0x1003)
+        self.assertEqual(error.error_code, 0x1003)
+
+    def test_truncate_error_summary(self):
+        """
+        Verify that TruncateError has the correct summary message
+        """
+        error = TruncateError(code=0x1003, message="test", info=None)
+        self.assertEqual(error.summary, "Error during truncate")
+
+
+if __name__ == '__main__':
+    unittest.main()