fix(core): handle non-iterable objects with __iter__ = None in metadata_to_dict

aws_xray_sdk/core/utils/conversion.py

@@ -1,3 +1,4 @@
+from collections.abc import Iterable
 import logging
 
 log = logging.getLogger(__name__)
@@ -17,12 +18,15 @@ def metadata_to_dict(obj):
             return str(obj)
         elif hasattr(obj, "_ast"):
             return metadata_to_dict(obj._ast())
-        elif hasattr(obj, "__iter__") and not isinstance(obj, str):
-            metadata = []
-            for item in obj:
-                metadata.append(metadata_to_dict(item))
-            return metadata
-        elif hasattr(obj, "__dict__"):
+        elif isinstance(obj, Iterable) and not isinstance(obj, str):
+            try:
+                metadata = []
+                for item in obj:
+                    metadata.append(metadata_to_dict(item))
+                return metadata
+            except TypeError:
+                pass
+        if hasattr(obj, "__dict__"):
             metadata = {}
             for key, value in vars(obj).items():
                 if not callable(value) and not key.startswith('_'):

tests/test_utils.py

@@ -92,4 +92,46 @@ def test_inject_trace_header_sampled():
 
     inject_trace_header(headers, subsegment)
 
-    assert 'Sampled=1' in headers['X-Amzn-Trace-Id']
+    assert 'Sampled=1' in headers['X-Amzn-Trace-Id']
+
+def test_metadata_to_dict_non_iterable_object():
+    from aws_xray_sdk.core.utils.conversion import metadata_to_dict
+
+    class MockMySQLConnection:
+        __iter__ = None
+
+        def __init__(self):
+            self.host = "localhost"
+            self.port = 3306
+            self._secret = "hidden"
+
+    conn = MockMySQLConnection()
+    result = metadata_to_dict(conn)
+    assert result == {"host": "localhost", "port": 3306}
+
+
+def test_metadata_to_dict_broken_iterable():
+    from aws_xray_sdk.core.utils.conversion import metadata_to_dict
+
+    class BrokenIterable:
+        def __iter__(self):
+            raise TypeError("iteration failed")
+
+        def __init__(self):
+            self.status = "active"
+            self._private = 123
+
+    obj = BrokenIterable()
+    result = metadata_to_dict(obj)
+    assert result == {"status": "active"}
+
+
+def test_metadata_to_dict_collection_types():
+    from aws_xray_sdk.core.utils.conversion import metadata_to_dict
+
+    assert metadata_to_dict({"k": "v"}) == {"k": "v"}
+    assert metadata_to_dict([1, "a", True]) == [1, "a", True]
+    assert metadata_to_dict((1, 2)) == [1, 2]
+    assert metadata_to_dict("text") == "text"
+    assert metadata_to_dict(42) == 42
+    assert metadata_to_dict(None) is None