fix: stop calling parent class root_validator if overridden (#2670)

* fix: stop calling parent class `root_validator` if overridden

* refactor: better name, default and typing

changes/1895-PrettyWood.md

@@ -0,0 +1 @@
+stop calling parent class `root_validator` if overridden

pydantic/main.py

@@ -249,8 +249,14 @@ class ModelMetaclass(ABCMeta):
             }
             or None,
             '__validators__': vg.validators,
-            '__pre_root_validators__': unique_list(pre_root_validators + pre_rv_new),
-            '__post_root_validators__': unique_list(post_root_validators + post_rv_new),
+            '__pre_root_validators__': unique_list(
+                pre_root_validators + pre_rv_new,
+                name_factory=lambda v: v.__name__,
+            ),
+            '__post_root_validators__': unique_list(
+                post_root_validators + post_rv_new,
+                name_factory=lambda skip_on_failure_and_v: skip_on_failure_and_v[1].__name__,
+            ),
             '__schema_cache__': {},
             '__json_encoder__': staticmethod(json_encoder),
             '__custom_root_type__': _custom_root_type,

pydantic/utils.py

@@ -279,16 +279,25 @@ def to_camel(string: str) -> str:
 T = TypeVar('T')
 
 
-def unique_list(input_list: Union[List[T], Tuple[T, ...]]) -> List[T]:
+def unique_list(
+    input_list: Union[List[T], Tuple[T, ...]],
+    *,
+    name_factory: Callable[[T], str] = str,
+) -> List[T]:
     """
     Make a list unique while maintaining order.
+    We update the list if another one with the same name is set
+    (e.g. root validator overridden in subclass)
     """
-    result = []
-    unique_set = set()
+    result: List[T] = []
+    result_names: List[str] = []
     for v in input_list:
-        if v not in unique_set:
-            unique_set.add(v)
+        v_name = name_factory(v)
+        if v_name not in result_names:
+            result_names.append(v_name)
             result.append(v)
+        else:
+            result[result_names.index(v_name)] = v
 
     return result
 

tests/test_validators.py

@@ -1256,3 +1256,39 @@ def test_exceptions_in_field_validators_restore_original_field_value():
     with pytest.raises(RuntimeError, match='test error'):
         model.foo = 'raise_exception'
     assert model.foo == 'foo'
+
+
+def test_overridden_root_validators(mocker):
+    validate_stub = mocker.stub(name='validate')
+
+    class A(BaseModel):
+        x: str
+
+        @root_validator(pre=True)
+        def pre_root(cls, values):
+            validate_stub('A', 'pre')
+            return values
+
+        @root_validator(pre=False)
+        def post_root(cls, values):
+            validate_stub('A', 'post')
+            return values
+
+    class B(A):
+        @root_validator(pre=True)
+        def pre_root(cls, values):
+            validate_stub('B', 'pre')
+            return values
+
+        @root_validator(pre=False)
+        def post_root(cls, values):
+            validate_stub('B', 'post')
+            return values
+
+    A(x='pika')
+    assert validate_stub.call_args_list == [mocker.call('A', 'pre'), mocker.call('A', 'post')]
+
+    validate_stub.reset_mock()
+
+    B(x='pika')
+    assert validate_stub.call_args_list == [mocker.call('B', 'pre'), mocker.call('B', 'post')]