really drop universal

* Fix problem where Model instancess are not considered subtypes of each other due to fallback_to_any = True. Fixes #52.

- Added a stub for __getstate__ to Model.
- Added a stub for clean() to Model.
- Correct arg type for sort_dependencies so they are covariant (Iterable rather than List).

Test ignores:
- Added some test ignores in cases where a model inherits from 2 different base models.
- Added some test ignores for cases that MyPy flags as errors due to variable redefinitions or imports that are incompatible types.

* Address review comment.

django-stubs/contrib/sessions/backends/base.pyi

@@ -1,8 +1,6 @@
 from datetime import datetime
 from typing import Any, Dict, Optional, Union
 
-from django.db.models.base import Model
-
 VALID_KEY_CHARS: Any
 
 class CreateError(Exception): ...
@@ -18,8 +16,8 @@ class SessionBase(Dict[str, Any]):
     def set_test_cookie(self) -> None: ...
     def test_cookie_worked(self) -> bool: ...
     def delete_test_cookie(self) -> None: ...
-    def encode(self, session_dict: Dict[str, Model]) -> str: ...
+    def encode(self, session_dict: Dict[str, Any]) -> str: ...
-    def decode(self, session_data: Union[bytes, str]) -> Dict[str, Model]: ...
+    def decode(self, session_data: Union[bytes, str]) -> Dict[str, Any]: ...
     def has_key(self, key: Any): ...
     def keys(self): ...
     def values(self): ...
@@ -33,7 +31,7 @@ class SessionBase(Dict[str, Any]):
     def get_expire_at_browser_close(self) -> bool: ...
     def flush(self) -> None: ...
     def cycle_key(self) -> None: ...
-    def exists(self, session_key: str) -> None: ...
+    def exists(self, session_key: str) -> bool: ...
     def create(self) -> None: ...
     def save(self, must_create: bool = ...) -> None: ...
     def delete(self, session_key: Optional[Any] = ...) -> None: ...

django-stubs/core/serializers/__init__.pyi

@@ -1,5 +1,4 @@
-from collections import OrderedDict
+from typing import Any, Callable, Dict, Iterator, List, Optional, Tuple, Type, Union, Iterable
-from typing import Any, Callable, Dict, Iterator, List, Optional, Tuple, Type, Union
 
 from django.apps.config import AppConfig
 from django.db.models.base import Model
@@ -33,5 +32,5 @@ def serialize(
 ) -> Optional[Union[bytes, str]]: ...
 def deserialize(format: str, stream_or_string: Any, **options: Any) -> Union[Iterator[Any], Deserializer]: ...
 def sort_dependencies(
-    app_list: Union[List[Tuple[AppConfig, None]], List[Tuple[str, List[Type[Model]]]]]
+    app_list: Union[Iterable[Tuple[AppConfig, None]], Iterable[Tuple[str, Iterable[Type[Model]]]]]
 ) -> List[Type[Model]]: ...

django-stubs/db/models/base.pyi

@@ -8,6 +8,7 @@ _Self = TypeVar("_Self", bound="Model")
 
 class Model(metaclass=ModelBase):
     class DoesNotExist(Exception): ...
+    class MultipleObjectsReturned(Exception): ...
     class Meta: ...
     _meta: Any
     _default_manager: Manager[Model]
@@ -15,6 +16,7 @@ class Model(metaclass=ModelBase):
     def __init__(self: _Self, *args, **kwargs) -> None: ...
     def delete(self, using: Any = ..., keep_parents: bool = ...) -> Tuple[int, Dict[str, int]]: ...
     def full_clean(self, exclude: Optional[List[str]] = ..., validate_unique: bool = ...) -> None: ...
+    def clean(self) -> None: ...
     def clean_fields(self, exclude: List[str] = ...) -> None: ...
     def validate_unique(self, exclude: List[str] = ...) -> None: ...
     def save(
@@ -34,6 +36,7 @@ class Model(metaclass=ModelBase):
     ): ...
     def refresh_from_db(self: _Self, using: Optional[str] = ..., fields: Optional[List[str]] = ...) -> _Self: ...
     def get_deferred_fields(self) -> Set[str]: ...
+    def __getstate__(self) -> dict: ...
 
 class ModelStateFieldsCacheDescriptor: ...
 

django-stubs/utils/decorators.pyi

@@ -1,7 +1,5 @@
 from typing import Any, Callable, Optional, Set, Tuple, Type, Union
 
-from django.middleware.cache import CacheMiddleware
-from django.test.testcases import LiveServerTestCase
 from django.utils.deprecation import MiddlewareMixin
 
 class classonlymethod(classmethod): ...
@@ -9,7 +7,7 @@ class classonlymethod(classmethod): ...
 def method_decorator(
     decorator: Union[Callable, Set[Callable], Tuple[Callable, Callable]], name: str = ...
 ) -> Callable: ...
-def decorator_from_middleware_with_args(middleware_class: Type[CacheMiddleware]) -> Callable: ...
+def decorator_from_middleware_with_args(middleware_class: Type[MiddlewareMixin]) -> Callable: ...
 def decorator_from_middleware(middleware_class: Type[MiddlewareMixin]) -> Callable: ...
 def available_attrs(fn: Any): ...
 def make_middleware_decorator(middleware_class: Type[MiddlewareMixin]) -> Callable: ...
@@ -17,5 +15,5 @@ def make_middleware_decorator(middleware_class: Type[MiddlewareMixin]) -> Callab
 class classproperty:
     fget: Optional[Callable] = ...
     def __init__(self, method: Optional[Callable] = ...) -> None: ...
-    def __get__(self, instance: Optional[LiveServerTestCase], cls: Type[LiveServerTestCase] = ...) -> str: ...
+    def __get__(self, instance: Any, cls: Optional[type] = ...) -> Any: ...
     def getter(self, method: Callable) -> classproperty: ...

mypy_django_plugin/transformers/models.py

@@ -5,7 +5,7 @@ import dataclasses
 from mypy.nodes import (
     ARG_STAR, ARG_STAR2, MDEF, Argument, CallExpr, ClassDef, Expression, IndexExpr, Lvalue, MemberExpr, MypyFile,
     NameExpr, StrExpr, SymbolTableNode, TypeInfo, Var,
-)
+    ARG_POS)
 from mypy.plugin import ClassDefContext
 from mypy.plugins.common import add_method
 from mypy.semanal import SemanticAnalyzerPass2
@@ -255,10 +255,23 @@ def add_dummy_init_method(ctx: ClassDefContext) -> None:
                       type_annotation=any, initializer=None, kind=ARG_STAR2)
 
     add_method(ctx, '__init__', [pos_arg, kw_arg], NoneTyp())
+
     # mark as model class
     ctx.cls.info.metadata.setdefault('django', {})['generated_init'] = True
 
 
+def add_get_set_attr_fallback_to_any(ctx: ClassDefContext):
+    any = AnyType(TypeOfAny.special_form)
+
+    name_arg = Argument(variable=Var('name', any),
+                        type_annotation=any, initializer=None, kind=ARG_POS)
+    add_method(ctx, '__getattr__', [name_arg], any)
+
+    value_arg = Argument(variable=Var('value', any),
+                         type_annotation=any, initializer=None, kind=ARG_POS)
+    add_method(ctx, '__setattr__', [name_arg, value_arg], any)
+
+
 def process_model_class(ctx: ClassDefContext) -> None:
     initializers = [
         InjectAnyAsBaseForNestedMeta,
@@ -273,4 +286,4 @@ def process_model_class(ctx: ClassDefContext) -> None:
     add_dummy_init_method(ctx)
 
     # allow unspecified attributes for now
-    ctx.cls.info.fallback_to_any = True
+    add_get_set_attr_fallback_to_any(ctx)

release.xsh

@@ -2,7 +2,7 @@
 
 try:
     pip install wheel twine
-    python setup.py sdist bdist_wheel --universal
+    python setup.py sdist bdist_wheel
     twine upload dist/*
 
 finally:

scripts/typecheck_tests.py

@@ -59,7 +59,12 @@ IGNORED_ERRORS = {
         'Argument 1 to "loads" has incompatible type "Union[bytes, str, None]"; '
         + 'expected "Union[str, bytes, bytearray]"',
         'Incompatible types in assignment (expression has type "None", variable has type Module)',
-        'note:'
+        'note:',
+        # Suppress false-positive error due to mypy being overly strict with base class compatibility checks even though
+        # objects/_default_manager are redefined in the subclass to be compatible with the base class definition.
+        # Can be removed when mypy issue is fixed: https://github.com/python/mypy/issues/2619
+        re.compile(r'Definition of "(objects|_default_manager)" in base class "[A-Za-z0-9]+" is incompatible with '
+                   r'definition in base class "[A-Za-z0-9]+"'),
     ],
     'admin_changelist': [
         'Incompatible types in assignment (expression has type "FilteredChildAdmin", variable has type "ChildAdmin")'
@@ -213,11 +218,12 @@ IGNORED_ERRORS = {
         'Unexpected keyword argument "headline__startswith" for "in_bulk" of "QuerySet"',
     ],
     'many_to_one': [
-        'Incompatible type for "parent" of "Child" (got "None", expected "Union[Parent, Combinable]")'
+        'Incompatible type for "parent" of "Child" (got "None", expected "Union[Parent, Combinable]")',
+        'Incompatible type for "parent" of "Child" (got "Child", expected "Union[Parent, Combinable]")'
     ],
     'model_meta': [
         '"object" has no attribute "items"',
-        '"Field" has no attribute "many_to_many"'
+        '"Field" has no attribute "many_to_many"',
     ],
     'model_forms': [
         'Argument "instance" to "InvalidModelForm" has incompatible type "Type[Category]"; expected "Optional[Model]"',
@@ -227,8 +233,14 @@ IGNORED_ERRORS = {
         'Incompatible types in assignment (expression has type "Type[Person]", variable has type',
         'Unexpected keyword argument "name" for "Person"',
         'Cannot assign multiple types to name "PersonTwoImages" without an explicit "Type[...]" annotation',
-        'Incompatible types in assignment (expression has type "Type[Person]", '
+        re.compile(
-        + 'base class "ImageFieldTestMixin" defined the type as "Type[PersonWithHeightAndWidth]")',
+            r'Incompatible types in assignment \(expression has type "Type\[.+?\]", base class "IntegerFieldTests"'
+            r' defined the type as "Type\[IntegerModel\]"\)'),
+        re.compile(r'Incompatible types in assignment \(expression has type "Type\[.+?\]", base class'
+                   r' "ImageFieldTestMixin" defined the type as "Type\[PersonWithHeightAndWidth\]"\)'),
+        'Incompatible import of "Person"',
+        'Incompatible types in assignment (expression has type "FloatModel", variable has type '
+        '"Union[float, int, str, Combinable]")',
     ],
     'model_formsets': [
         'Incompatible types in string interpolation (expression has type "object", '
@@ -261,7 +273,7 @@ IGNORED_ERRORS = {
         'Argument 1 to "RunPython" has incompatible type "str"; expected "Callable[..., Any]"',
         'FakeLoader',
         'Argument 1 to "append" of "list" has incompatible type "AddIndex"; expected "CreateModel"',
-        'Unsupported operand types for - ("Set[Any]" and "None")'
+        'Unsupported operand types for - ("Set[Any]" and "None")',
     ],
     'middleware_exceptions': [
         'Argument 1 to "append" of "list" has incompatible type "Tuple[Any, Any]"; expected "str"'
@@ -282,7 +294,11 @@ IGNORED_ERRORS = {
         + 'expected "Optional[Type[JSONEncoder]]"',
         'for model "CITestModel"',
         'Incompatible type for "field" of "IntegerArrayModel" (got "None", '
-        + 'expected "Union[Sequence[int], Combinable]")'
+        + 'expected "Union[Sequence[int], Combinable]")',
+        re.compile(r'Incompatible types in assignment \(expression has type "Type\[.+?\]", base class "UnaccentTest" '
+                   r'defined the type as "Type\[CharFieldModel\]"\)'),
+        'Incompatible types in assignment (expression has type "Type[TextFieldModel]", base class "TrigramTest" '
+        'defined the type as "Type[CharFieldModel]")',
     ],
     'properties': [
         re.compile('Unexpected attribute "(full_name|full_name_2)" for model "Person"')
@@ -291,6 +307,12 @@ IGNORED_ERRORS = {
         'Incompatible types in assignment (expression has type "None", variable has type "str")',
         'Invalid index type "Optional[str]" for "Dict[str, int]"; expected type "str"',
         'No overload variant of "values_list" of "QuerySet" matches argument types "str", "bool", "bool"',
+        'Unsupported operand types for & ("QuerySet[Author, Author]" and "QuerySet[Tag, Tag]")',
+        'Unsupported operand types for | ("QuerySet[Author, Author]" and "QuerySet[Tag, Tag]")',
+        'Incompatible types in assignment (expression has type "ObjectB", variable has type "ObjectA")',
+        'Incompatible types in assignment (expression has type "ObjectC", variable has type "ObjectA")',
+        'Incompatible type for "objectb" of "ObjectC" (got "ObjectA", expected'
+        ' "Union[ObjectB, Combinable, None, None]")',
     ],
     'requests': [
         'Incompatible types in assignment (expression has type "Dict[str, str]", variable has type "QueryDict")'
@@ -303,6 +325,9 @@ IGNORED_ERRORS = {
         '"None" has no attribute "__iter__"',
         'has no attribute "read_by"'
     ],
+    'proxy_model_inheritance': [
+        'Incompatible import of "ProxyModel"'
+    ],
     'signals': [
         'Argument 1 to "append" of "list" has incompatible type "Tuple[Any, Any, Optional[Any], Any]"; '
         + 'expected "Tuple[Any, Any, Any]"'
@@ -387,7 +412,8 @@ IGNORED_ERRORS = {
         'Incompatible types in assignment (expression has type "None", variable has type "int")',
     ],
     'select_related_onetoone': [
-        '"None" has no attribute'
+        '"None" has no attribute',
+        'Incompatible types in assignment (expression has type "Parent2", variable has type "Parent1")',
     ],
     'servers': [
         re.compile('Argument [0-9] to "WSGIRequestHandler"')

setup.cfg

@@ -22,8 +22,5 @@ addopts =
     -s
     -v
 
-[bdist_wheel]
-universal = 1
-
 [metadata]
 license_file = LICENSE.txt

setup.py

@@ -21,7 +21,7 @@ with open('README.md', 'r') as f:
     readme = f.read()
 
 dependencies = [
-    'mypy>=0.670',
+    'mypy>=0.670,<0.700',
     'typing-extensions'
 ]
 if sys.version_info[:2] < (3, 7):
@@ -30,7 +30,7 @@ if sys.version_info[:2] < (3, 7):
 
 setup(
     name="django-stubs",
-    version="0.10.0",
+    version="0.11.0",
     description='Django mypy stubs',
     long_description=readme,
     long_description_content_type='text/markdown',
@@ -39,7 +39,7 @@ setup(
     author="Maksim Kurnikov",
     author_email="maxim.kurnikov@gmail.com",
     py_modules=[],
-    python_requires='>=3',
+    python_requires='>=3.6',
     install_requires=dependencies,
     packages=['django-stubs', *find_packages()],
     package_data={'django-stubs': find_stub_files('django-stubs')},

test-data/typecheck/managers.test

@@ -21,7 +21,7 @@ from django.db import models
 class MyModel(models.Model):
     authors = models.Manager[MyModel]()
 reveal_type(MyModel.authors)  # E: Revealed type is 'django.db.models.manager.Manager[main.MyModel]'
-reveal_type(MyModel.objects)  # E: Revealed type is 'Any'
+MyModel.objects  # E: "Type[MyModel]" has no attribute "objects"
 [out]
 
 [CASE test_model_objects_attribute_present_in_case_of_model_cls_passed_as_generic_parameter]

test-data/typecheck/model.test

@@ -0,0 +1,28 @@
+[CASE test_model_subtype_relationship_and_getting_and_setting_attributes]
+from django.db import models
+
+class A(models.Model):
+    pass
+
+class B(models.Model):
+    b_attr = 1
+    pass
+
+class C(A):
+    pass
+
+def service(a: A) -> int:
+    pass
+
+a_instance = A()
+b_instance = B()
+reveal_type(b_instance.b_attr) # E: Revealed type is 'builtins.int'
+
+
+reveal_type(b_instance.non_existent_attribute) # E: Revealed type is 'Any'
+b_instance.non_existent_attribute = 2
+
+service(b_instance)  # E: Argument 1 to "service" has incompatible type "B"; expected "A"
+
+c_instance = C()
+service(c_instance)

test-data/typecheck/model_create.test

@@ -27,12 +27,16 @@ class Parent1(models.Model):
 class Parent2(models.Model):
     id2 = models.AutoField(primary_key=True)
     name2 = models.CharField(max_length=50)
+
+# TODO: Remove the 2 expected errors on the next line once mypy issue https://github.com/python/mypy/issues/2619 is resolved:
 class Child1(Parent1, Parent2):
     value = models.IntegerField()
 class Child4(Child1):
     value4 = models.IntegerField()
 Child4.objects.create(name1='n1', name2='n2', value=1, value4=4)
 [out]
+main:10: error: Definition of "objects" in base class "Parent1" is incompatible with definition in base class "Parent2"
+main:10: error: Definition of "_default_manager" in base class "Parent1" is incompatible with definition in base class "Parent2"
 
 [CASE optional_primary_key_for_create_is_error]
 from django.db import models