__pydantic_extra__ alwasy a dict if extra=allow

Author: samuelcolvin

src/serializers/fields.rs

@@ -115,12 +115,8 @@ impl GeneralFieldsSerializer {
     fn extract_dicts<'a>(&self, value: &'a PyAny) -> Option<(&'a PyDict, Option<&'a PyDict>)> {
         match self.mode {
             FieldsMode::ModelExtra => {
-                if let Ok((main_dict, extra_dict)) = value.extract::<(&PyDict, &PyAny)>() {
-                    if let Ok(extra_dict) = extra_dict.downcast::<PyDict>() {
-                        Some((main_dict, Some(extra_dict)))
-                    } else {
-                        Some((main_dict, None))
-                    }
+                if let Ok((main_dict, extra_dict)) = value.extract::<(&PyDict, &PyDict)>() {
+                    Some((main_dict, Some(extra_dict)))
                 } else {
                     None
                 }

src/validators/model_fields.rs

@@ -249,6 +249,13 @@ impl Validator for ModelFieldsValidator {
             Err(ValError::LineErrors(errors))
         } else {
             let fields_set = PySet::new(py, &fields_set_vec)?;
+
+            // if we have extra=allow, but we didn't create a dict because we were validate attributes, set it now
+            // so __pydantic_extra__ is always a dict if extra=allow
+            if model_extra_dict_op.is_none() && matches!(self.extra_behavior, ExtraBehavior::Allow) {
+                model_extra_dict_op = Some(PyDict::new(py));
+            };
+
             Ok((model_dict, model_extra_dict_op, fields_set).to_object(py))
         }
     }

tests/serializers/test_model.py

@@ -121,8 +121,8 @@ def test_model_allow_extra():
             extra_behavior='allow',
         )
     )
-    assert s.to_python(BasicModel(foo=1, bar=b'more', __pydantic_extra__=None)) == IsStrictDict(foo=1, bar=b'more')
-    assert s.to_python(BasicModel(bar=b'more', foo=1, __pydantic_extra__=None)) == IsStrictDict(bar=b'more', foo=1)
+    assert s.to_python(BasicModel(foo=1, bar=b'more', __pydantic_extra__={})) == IsStrictDict(foo=1, bar=b'more')
+    assert s.to_python(BasicModel(bar=b'more', foo=1, __pydantic_extra__={})) == IsStrictDict(bar=b'more', foo=1)
     assert s.to_python(BasicModel(foo=1, __pydantic_extra__=dict(c=3), bar=b'more')) == IsStrictDict(
         foo=1, bar=b'more', c=3
     )

tests/validators/test_model_fields.py

@@ -1107,11 +1107,11 @@ class MyDataclass:
         }
     )
 
-    assert v.validate_python(Foobar()) == ({'a': 1}, None, {'a'})
-    assert v.validate_python(MyDataclass()) == ({'a': 1}, None, {'a'})
-    assert v.validate_python(Cls(a=1, b=2, c='ham')) == ({'a': 1}, None, {'a'})
-    assert v.validate_python(Cls(a=1, b=datetime(2000, 1, 1))) == ({'a': 1}, None, {'a'})
-    assert v.validate_python(Cls(a=1, b=datetime.now, c=lambda: 42)) == ({'a': 1}, None, {'a'})
+    assert v.validate_python(Foobar()) == ({'a': 1}, {}, {'a'})
+    assert v.validate_python(MyDataclass()) == ({'a': 1}, {}, {'a'})
+    assert v.validate_python(Cls(a=1, b=2, c='ham')) == ({'a': 1}, {}, {'a'})
+    assert v.validate_python(Cls(a=1, b=datetime(2000, 1, 1))) == ({'a': 1}, {}, {'a'})
+    assert v.validate_python(Cls(a=1, b=datetime.now, c=lambda: 42)) == ({'a': 1}, {}, {'a'})
 
 
 def test_from_attributes_extra_ignore_no_attributes_accessed() -> None:
@@ -1360,8 +1360,8 @@ def test_alias_extra_from_attributes():
         }
     )
     assert v.validate_python({'FieldA': 1}) == ({'field_a': 1}, {}, {'field_a'})
-    assert v.validate_python(Cls(FieldA=1)) == ({'field_a': 1}, None, {'field_a'})
-    assert v.validate_python(Cls(foo=[1, 2, 3])) == ({'field_a': 3}, None, {'field_a'})
+    assert v.validate_python(Cls(FieldA=1)) == ({'field_a': 1}, {}, {'field_a'})
+    assert v.validate_python(Cls(foo=[1, 2, 3])) == ({'field_a': 3}, {}, {'field_a'})
     assert v.validate_python({'foo': [1, 2, 3]}) == ({'field_a': 3}, {}, {'field_a'})
 
 
@@ -1377,8 +1377,8 @@ def test_alias_extra_by_name(py_and_json: PyAndJson):
     )
     assert v.validate_test({'FieldA': 1}) == ({'field_a': 1}, {}, {'field_a'})
     assert v.validate_test({'field_a': 1}) == ({'field_a': 1}, {}, {'field_a'})
-    assert v.validate_python(Cls(FieldA=1)) == ({'field_a': 1}, None, {'field_a'})
-    assert v.validate_python(Cls(field_a=1)) == ({'field_a': 1}, None, {'field_a'})
+    assert v.validate_python(Cls(FieldA=1)) == ({'field_a': 1}, {}, {'field_a'})
+    assert v.validate_python(Cls(field_a=1)) == ({'field_a': 1}, {}, {'field_a'})
 
 
 def test_alias_extra_forbid(py_and_json: PyAndJson):