fix: update all modified field values in root_validator when validate_assignment is on (#2119)

* fix: update all modified field values in `root_validator` when `validate_assignment` is on

closes #2116

* chore: update root_validator name

Co-authored-by: Arthur Pastel <[email protected]>

Co-authored-by: Arthur Pastel <[email protected]>

Author: 2 people

changes/2116-PrettyWood.md

@@ -0,0 +1 @@
+fix: update all modified field values in `root_validator` when `validate_assignment` is on

pydantic/main.py

@@ -406,7 +406,12 @@ def __setattr__(self, name, value):  # noqa: C901 (ignore complexity)
             if errors:
                 raise ValidationError(errors, self.__class__)
 
-        self.__dict__[name] = value
+            # update the whole __dict__ as other values than just `value`
+            # may be changed (e.g. with `root_validator`)
+            object_setattr(self, '__dict__', new_values)
+        else:
+            self.__dict__[name] = value
+
         self.__fields_set__.add(name)
 
     def __getstate__(self) -> 'DictAny':

tests/test_main.py

@@ -666,6 +666,28 @@ def current_lessequal_500(cls, values):
     ]
 
 
+def test_root_validator_many_values_change():
+    """It should run root_validator on assignment and update ALL concerned fields"""
+
+    class Rectangle(BaseModel):
+        width: float
+        height: float
+        area: float = None
+
+        class Config:
+            validate_assignment = True
+
+        @root_validator
+        def set_area(cls, values):
+            values['area'] = values['width'] * values['height']
+            return values
+
+    r = Rectangle(width=1, height=1)
+    assert r.area == 1
+    r.height = 5
+    assert r.area == 5
+
+
 def test_enum_values():
     FooEnum = Enum('FooEnum', {'foo': 'foo', 'bar': 'bar'})