Support returning the correct values for the different QuerySet methods when using .values() and .values_list(). (#33)

* Support returning the correct values for the different QuerySet methods when using .values() and .values_list().

* Fix slicing on QuerySet. Fix django queries test, and remove some ignored errors that are no longer needed.

* Remove accidental change in RawQuerySet.

* Readded some still-necessary ignores to aggregation django test.

* Add more tests of first/last/earliest/last/__getitem__, per mkurnikov's comments.

- Fix .iterator()

* Re-add Iterator as base-class of QuerySet.

* Make QuerySet a Collection.

* - Fix return type for QuerySet.select_for_update().
- Use correct return type for QuerySet.dates() / QuerySet.datetimes().
- Use correct type params in return type for QuerySet.__and__ / QuerySet.__or__
- Re-add Sized as base class for QuerySet.
- Add test of .all() for all _Row types.
- Add test of .get() for all _Row types.
- Remove some redundant QuerySet method tests.

* Automatically fill in second type parameter for QuerySet.

... if second parameter is omitted.

django-stubs/db/models/manager.pyi

@@ -5,7 +5,7 @@ from django.db.models.query import QuerySet
 
 _T = TypeVar("_T", bound=Model, covariant=True)
 
-class BaseManager(QuerySet[_T]):
+class BaseManager(QuerySet[_T, _T]):
     creation_counter: int = ...
     auto_created: bool = ...
     use_in_migrations: bool = ...
@@ -21,7 +21,7 @@ class BaseManager(QuerySet[_T]):
     def _get_queryset_methods(cls, queryset_class: type) -> Dict[str, Any]: ...
     def contribute_to_class(self, model: Type[Model], name: str) -> None: ...
     def db_manager(self, using: Optional[str] = ..., hints: Optional[Dict[str, Model]] = ...) -> Manager: ...
-    def get_queryset(self) -> QuerySet[_T]: ...
+    def get_queryset(self) -> QuerySet[_T, _T]: ...
 
 class Manager(BaseManager[_T]): ...
 

django-stubs/db/models/query.pyi

@@ -1,3 +1,4 @@
+import datetime
 from typing import (
     Any,
     Dict,
@@ -13,6 +14,9 @@ from typing import (
     TypeVar,
     Union,
     overload,
+    Generic,
+    NamedTuple,
+    Collection,
 )
 
 from django.db.models.base import Model
@@ -46,7 +50,7 @@ class FlatValuesListIterable(BaseIterable):
 
 _T = TypeVar("_T", bound=models.Model, covariant=True)
 
-class QuerySet(Iterable[_T], Sized):
+class QuerySet(Generic[_T, _Row], Collection[_Row], Sized):
     query: Query
     def __init__(
         self,
@@ -58,32 +62,33 @@ class QuerySet(Iterable[_T], Sized):
     @classmethod
     def as_manager(cls) -> Manager[Any]: ...
     def __len__(self) -> int: ...
-    def __iter__(self) -> Iterator[_T]: ...
+    def __iter__(self) -> Iterator[_Row]: ...
+    def __contains__(self, x: object) -> bool: ...
+    @overload
+    def __getitem__(self, i: int) -> _Row: ...
+    @overload
+    def __getitem__(self, s: slice) -> QuerySet[_T, _Row]: ...
     def __bool__(self) -> bool: ...
     def __class_getitem__(cls, item: Type[_T]):
         pass
     def __getstate__(self) -> Dict[str, Any]: ...
-    @overload
-    def __getitem__(self, k: int) -> _T: ...
-    @overload
-    def __getitem__(self, k: str) -> Any: ...
-    @overload
-    def __getitem__(self, k: slice) -> QuerySet[_T]: ...
-    def __and__(self, other: QuerySet) -> QuerySet: ...
-    def __or__(self, other: QuerySet) -> QuerySet: ...
-    def iterator(self, chunk_size: int = ...) -> Iterator[_T]: ...
+    # __and__ and __or__ ignore the other QuerySet's _Row type parameter because they use the same row type as the self QuerySet.
+    # Technically, the other QuerySet must be of the same type _T, but _T is covariant
+    def __and__(self, other: QuerySet[_T, Any]) -> QuerySet[_T, _Row]: ...
+    def __or__(self, other: QuerySet[_T, Any]) -> QuerySet[_T, _Row]: ...
+    def iterator(self, chunk_size: int = ...) -> Iterator[_Row]: ...
     def aggregate(self, *args: Any, **kwargs: Any) -> Dict[str, Any]: ...
-    def get(self, *args: Any, **kwargs: Any) -> _T: ...
+    def get(self, *args: Any, **kwargs: Any) -> _Row: ...
     def create(self, **kwargs: Any) -> _T: ...
     def bulk_create(self, objs: Iterable[Model], batch_size: Optional[int] = ...) -> List[_T]: ...
     def get_or_create(self, defaults: Optional[MutableMapping[str, Any]] = ..., **kwargs: Any) -> Tuple[_T, bool]: ...
     def update_or_create(
         self, defaults: Optional[MutableMapping[str, Any]] = ..., **kwargs: Any
     ) -> Tuple[_T, bool]: ...
-    def earliest(self, *fields: Any, field_name: Optional[Any] = ...) -> _T: ...
-    def latest(self, *fields: Any, field_name: Optional[Any] = ...) -> _T: ...
-    def first(self) -> Optional[_T]: ...
-    def last(self) -> Optional[_T]: ...
+    def earliest(self, *fields: Any, field_name: Optional[Any] = ...) -> _Row: ...
+    def latest(self, *fields: Any, field_name: Optional[Any] = ...) -> _Row: ...
+    def first(self) -> Optional[_Row]: ...
+    def last(self) -> Optional[_Row]: ...
     def in_bulk(self, id_list: Iterable[Any] = ..., *, field_name: str = ...) -> Dict[Any, _T]: ...
     def delete(self) -> Tuple[int, Dict[str, int]]: ...
     def update(self, **kwargs: Any) -> int: ...
@@ -93,31 +98,38 @@ class QuerySet(Iterable[_T], Sized):
     def raw(
         self, raw_query: str, params: Any = ..., translations: Optional[Dict[str, str]] = ..., using: None = ...
     ) -> RawQuerySet: ...
-    def values(self, *fields: Union[str, Combinable], **expressions: Any) -> QuerySet: ...
-    def values_list(self, *fields: Union[str, Combinable], flat: bool = ..., named: bool = ...) -> QuerySet: ...
-    # @overload
-    # def values_list(self, *fields: Union[str, Combinable], named: Literal[True]) -> NamedValuesListIterable: ...
-    # @overload
-    # def values_list(self, *fields: Union[str, Combinable], flat: Literal[True]) -> FlatValuesListIterable: ...
-    # @overload
-    # def values_list(self, *fields: Union[str, Combinable]) -> ValuesListIterable: ...
-    def dates(self, field_name: str, kind: str, order: str = ...) -> QuerySet: ...
-    def datetimes(self, field_name: str, kind: str, order: str = ..., tzinfo: None = ...) -> QuerySet: ...
-    def none(self) -> QuerySet[_T]: ...
-    def all(self) -> QuerySet[_T]: ...
-    def filter(self, *args: Any, **kwargs: Any) -> QuerySet[_T]: ...
-    def exclude(self, *args: Any, **kwargs: Any) -> QuerySet[_T]: ...
-    def complex_filter(self, filter_obj: Any) -> QuerySet[_T]: ...
+    def values(self, *fields: Union[str, Combinable], **expressions: Any) -> QuerySet[_T, Dict[str, Any]]: ...
+    @overload
+    def values_list(
+        self, *fields: Union[str, Combinable], flat: Literal[False] = ..., named: Literal[True]
+    ) -> QuerySet[_T, NamedTuple]: ...
+    @overload
+    def values_list(
+        self, *fields: Union[str, Combinable], flat: Literal[True], named: Literal[False] = ...
+    ) -> QuerySet[_T, Any]: ...
+    @overload
+    def values_list(
+        self, *fields: Union[str, Combinable], flat: Literal[False] = ..., named: Literal[False] = ...
+    ) -> QuerySet[_T, Tuple]: ...
+    def dates(self, field_name: str, kind: str, order: str = ...) -> QuerySet[_T, datetime.date]: ...
+    def datetimes(
+        self, field_name: str, kind: str, order: str = ..., tzinfo: None = ...
+    ) -> QuerySet[_T, datetime.datetime]: ...
+    def none(self) -> QuerySet[_T, _Row]: ...
+    def all(self) -> QuerySet[_T, _Row]: ...
+    def filter(self, *args: Any, **kwargs: Any) -> QuerySet[_T, _Row]: ...
+    def exclude(self, *args: Any, **kwargs: Any) -> QuerySet[_T, _Row]: ...
+    def complex_filter(self, filter_obj: Any) -> QuerySet[_T, _Row]: ...
     def count(self) -> int: ...
-    def union(self, *other_qs: Any, all: bool = ...) -> QuerySet[_T]: ...
-    def intersection(self, *other_qs: Any) -> QuerySet[_T]: ...
-    def difference(self, *other_qs: Any) -> QuerySet[_T]: ...
-    def select_for_update(self, nowait: bool = ..., skip_locked: bool = ..., of: Tuple = ...) -> QuerySet: ...
-    def select_related(self, *fields: Any) -> QuerySet[_T]: ...
-    def prefetch_related(self, *lookups: Any) -> QuerySet[_T]: ...
-    def annotate(self, *args: Any, **kwargs: Any) -> QuerySet[_T]: ...
-    def order_by(self, *field_names: Any) -> QuerySet[_T]: ...
-    def distinct(self, *field_names: Any) -> QuerySet[_T]: ...
+    def union(self, *other_qs: Any, all: bool = ...) -> QuerySet[_T, _Row]: ...
+    def intersection(self, *other_qs: Any) -> QuerySet[_T, _Row]: ...
+    def difference(self, *other_qs: Any) -> QuerySet[_T, _Row]: ...
+    def select_for_update(self, nowait: bool = ..., skip_locked: bool = ..., of: Tuple = ...) -> QuerySet[_T, _Row]: ...
+    def select_related(self, *fields: Any) -> QuerySet[_T, _Row]: ...
+    def prefetch_related(self, *lookups: Any) -> QuerySet[_T, _Row]: ...
+    def annotate(self, *args: Any, **kwargs: Any) -> QuerySet[_T, _Row]: ...
+    def order_by(self, *field_names: Any) -> QuerySet[_T, _Row]: ...
+    def distinct(self, *field_names: Any) -> QuerySet[_T, _Row]: ...
     def extra(
         self,
         select: Optional[Dict[str, Any]] = ...,
@@ -126,11 +138,11 @@ class QuerySet(Iterable[_T], Sized):
         tables: Optional[List[str]] = ...,
         order_by: Optional[Sequence[str]] = ...,
         select_params: Optional[Sequence[Any]] = ...,
-    ) -> QuerySet[_T]: ...
-    def reverse(self) -> QuerySet[_T]: ...
-    def defer(self, *fields: Any) -> QuerySet[_T]: ...
-    def only(self, *fields: Any) -> QuerySet[_T]: ...
-    def using(self, alias: Optional[str]) -> QuerySet[_T]: ...
+    ) -> QuerySet[_T, _Row]: ...
+    def reverse(self) -> QuerySet[_T, _Row]: ...
+    def defer(self, *fields: Any) -> QuerySet[_T, _Row]: ...
+    def only(self, *fields: Any) -> QuerySet[_T, _Row]: ...
+    def using(self, alias: Optional[str]) -> QuerySet[_T, _Row]: ...
     @property
     def ordered(self) -> bool: ...
     @property
@@ -159,7 +171,7 @@ class RawQuerySet(Iterable[_T], Sized):
     @overload
     def __getitem__(self, k: str) -> Any: ...
     @overload
-    def __getitem__(self, k: slice) -> QuerySet[_T]: ...
+    def __getitem__(self, k: slice) -> RawQuerySet[_T]: ...
     @property
     def columns(self) -> List[str]: ...
     @property

django-stubs/shortcuts.pyi

@@ -31,6 +31,6 @@ def redirect(
 
 _T = TypeVar("_T", bound=Model)
 
-def get_object_or_404(klass: Union[Type[_T], Manager[_T], QuerySet[_T]], *args: Any, **kwargs: Any) -> _T: ...
-def get_list_or_404(klass: Union[Type[_T], Manager[_T], QuerySet[_T]], *args: Any, **kwargs: Any) -> List[_T]: ...
+def get_object_or_404(klass: Union[Type[_T], Manager[_T], QuerySet[_T, _T]], *args: Any, **kwargs: Any) -> _T: ...
+def get_list_or_404(klass: Union[Type[_T], Manager[_T], QuerySet[_T, _T]], *args: Any, **kwargs: Any) -> List[_T]: ...
 def resolve_url(to: Union[Callable, Model, str], *args: Any, **kwargs: Any) -> str: ...