Fix issue where StripeObjects in lists would not be converted to dicts

stripe/stripe_object.py

@@ -278,11 +278,20 @@ def to_dict(self):
         return dict(self)
 
     def to_dict_recursive(self):
-        d = dict(self)
-        for k, v in six.iteritems(d):
-            if isinstance(v, StripeObject):
-                d[k] = v.to_dict_recursive()
-        return d
+        def maybe_to_dict_recursive(value):
+            if value is None:
+                return None
+            elif isinstance(value, StripeObject):
+                return value.to_dict_recursive()
+            else:
+                return value
+
+        return {
+            key: list(map(maybe_to_dict_recursive, value))
+            if isinstance(value, list)
+            else maybe_to_dict_recursive(value)
+            for key, value in six.iteritems(dict(self))
+        }
 
     @property
     def stripe_id(self):

tests/test_stripe_object.py

@@ -291,6 +291,30 @@ def test_deepcopy(self):
         # Verify that we're actually deep copying nested values.
         assert id(nested) != id(copied.nested)
 
+    def test_to_dict_recursive(self):
+        foo = stripe.stripe_object.StripeObject.construct_from(
+            {"value": "foo"}, "mykey"
+        )
+        bar = stripe.stripe_object.StripeObject.construct_from(
+            {"value": "bar"}, "mykey"
+        )
+        obj = stripe.stripe_object.StripeObject.construct_from(
+            {"empty": "", "value": "foobar", "nested": [foo, bar]}, "mykey"
+        )
+
+        d = obj.to_dict_recursive()
+        assert d == {
+            "empty": "",
+            "value": "foobar",
+            "nested": [{"value": "foo"}, {"value": "bar"}],
+        }
+        assert not isinstance(
+            d["nested"][0], stripe.stripe_object.StripeObject
+        )
+        assert not isinstance(
+            d["nested"][1], stripe.stripe_object.StripeObject
+        )
+
     def test_serialize_empty_string_unsets(self):
         class SerializeToEmptyString(stripe.stripe_object.StripeObject):
             def serialize(self, previous):