fix: Verify error gets raised 2

Author: tmathern

tests/test_unit_tests.py

@@ -1049,6 +1049,11 @@ def error_callback_signer(data: bytes) -> bytes:
                     signer=signer
                 )
 
+            # Verify the output file stays empty,
+            # as no data should have been written
+            self.assertTrue(os.path.exists(output_path))
+            self.assertEqual(os.path.getsize(output_path), 0)
+
         finally:
             shutil.rmtree(temp_dir)