fix: Serialize sets into JSON (getsentry#781)

Fix getsentry#780

Author: untitaker

sentry_sdk/serializer.py

@@ -36,14 +36,14 @@
 if PY2:
     # Importing ABCs from collections is deprecated, and will stop working in 3.8
     # https://github.com/python/cpython/blob/master/Lib/collections/__init__.py#L49
-    from collections import Mapping, Sequence
+    from collections import Mapping, Sequence, Set
 
     serializable_str_types = string_types
 
 else:
     # New in 3.3
     # https://docs.python.org/3/library/collections.abc.html
-    from collections.abc import Mapping, Sequence
+    from collections.abc import Mapping, Sequence, Set
 
     # Bytes are technically not strings in Python 3, but we can serialize them
     serializable_str_types = (str, bytes)
@@ -291,7 +291,9 @@ def _serialize_node_impl(
 
             return rv_dict
 
-        elif not isinstance(obj, serializable_str_types) and isinstance(obj, Sequence):
+        elif not isinstance(obj, serializable_str_types) and isinstance(
+            obj, (Set, Sequence)
+        ):
             rv_list = []
 
             for i, v in enumerate(obj):

tests/test_serializer.py

@@ -55,6 +55,19 @@ def inner(message, **kwargs):
     return inner
 
 
+@pytest.fixture
+def extra_normalizer(relay_normalize):
+    if relay_normalize({"test": "test"}) is None:
+        pytest.skip("no relay available")
+
+    def inner(message, **kwargs):
+        event = serialize({"extra": {"foo": message}}, **kwargs)
+        normalized = relay_normalize(event)
+        return normalized["extra"]["foo"]
+
+    return inner
+
+
 def test_bytes_serialization_decode(message_normalizer):
     binary = b"abc123\x80\xf0\x9f\x8d\x95"
     result = message_normalizer(binary, should_repr_strings=False)
@@ -66,3 +79,8 @@ def test_bytes_serialization_repr(message_normalizer):
     binary = b"abc123\x80\xf0\x9f\x8d\x95"
     result = message_normalizer(binary, should_repr_strings=True)
     assert result == r"b'abc123\x80\xf0\x9f\x8d\x95'"
+
+
+def test_serialize_sets(extra_normalizer):
+    result = extra_normalizer({1, 2, 3})
+    assert result == [1, 2, 3]