Add types for GeneratedField

django-stubs/db/models/__init__.pyi

@@ -83,6 +83,7 @@ from .fields.files import FieldFile as FieldFile
 from .fields.files import FileDescriptor as FileDescriptor
 from .fields.files import FileField as FileField
 from .fields.files import ImageField as ImageField
+from .fields.generated import GeneratedField as GeneratedField
 from .fields.json import JSONField as JSONField
 from .fields.proxy import OrderWrt as OrderWrt
 from .fields.related import ForeignKey as ForeignKey

django-stubs/db/models/fields/generated.pyi

@@ -0,0 +1,83 @@
+from collections.abc import Iterable
+from typing import Any, Literal, Never, TypeVar, overload
+
+from django.db.models import Combinable, Expression, ForeignObjectRel
+from django.db.models.expressions import Col
+
+from . import Field, _ErrorMessagesToOverride, _ValidatorCallable
+from .mixins import CheckFieldDefaultMixin
+
+_GT = TypeVar("_GT", bound=Any | None)
+
+class GeneratedField(CheckFieldDefaultMixin, Field[Never, _GT]):
+    generated: Literal[True]
+    db_returning: Literal[True]
+    expression: Combinable | Expression
+
+    @overload
+    def __new__(
+        cls,
+        *,
+        expression: Combinable | Expression,
+        output_field: Field[Any, _GT],
+        db_persist: bool,
+        #
+        verbose_name: str | None = ...,
+        name: str | None = ...,
+        primary_key: bool = ...,
+        max_length: int | None = ...,
+        unique: bool = ...,
+        blank: Literal[True] = ...,
+        null: Literal[False] = False,
+        db_index: bool = ...,
+        rel: ForeignObjectRel | None = ...,
+        editable: Literal[False] = ...,
+        serialize: bool = ...,
+        unique_for_date: str | None = ...,
+        unique_for_month: str | None = ...,
+        unique_for_year: str | None = ...,
+        choices: Iterable[tuple[Any, str] | tuple[str, Iterable[tuple[Any, str]]]] = ...,
+        help_text: str = ...,
+        db_column: str | None = ...,
+        db_tablespace: str | None = ...,
+        auto_created: bool = ...,
+        validators: Iterable[_ValidatorCallable] = ...,
+        error_messages: _ErrorMessagesToOverride | None = ...,
+        db_comment: str | None = ...,
+    ) -> GeneratedField[_GT]: ...
+    @overload
+    def __new__(
+        cls,
+        *,
+        expression: Combinable | Expression,
+        output_field: Field[Any, _GT],
+        db_persist: bool,
+        #
+        verbose_name: str | None = ...,
+        name: str | None = ...,
+        primary_key: bool = ...,
+        max_length: int | None = ...,
+        unique: bool = ...,
+        blank: Literal[True] = ...,
+        null: Literal[True],
+        db_index: bool = ...,
+        rel: ForeignObjectRel | None = ...,
+        editable: Literal[False] = ...,
+        serialize: bool = ...,
+        unique_for_date: str | None = ...,
+        unique_for_month: str | None = ...,
+        unique_for_year: str | None = ...,
+        choices: Iterable[tuple[Any, str] | tuple[str, Iterable[tuple[Any, str]]]] = ...,
+        help_text: str = ...,
+        db_column: str | None = ...,
+        db_tablespace: str | None = ...,
+        auto_created: bool = ...,
+        validators: Iterable[_ValidatorCallable] = ...,
+        error_messages: _ErrorMessagesToOverride | None = ...,
+        db_comment: str | None = ...,
+    ) -> GeneratedField[_GT | None]: ...
+    @property
+    def cached_col(self) -> Col: ...
+    def generated_sql(self, connection: Any) -> tuple[str, list[Any]]: ...
+
+__all__ = ["GeneratedField"]

tests/trout/models.py

@@ -42,6 +42,8 @@
 )
 from psycopg2.extras import execute_values
 
+from django.db.models.fields.generated import GeneratedField
+
 
 class CustomChoices(models.Choices):
     A = "B", "A"
@@ -269,6 +271,18 @@ class Comment(models.Model):
         object_id_field="generic_id",
     )
 
+    generated_field = GeneratedField(
+        expression=models.F("integer") + 1,
+        output_field=models.IntegerField(),
+        db_persist=True,
+    )
+    nullable_generated_field = GeneratedField(
+        expression=models.F("integer_nullable") + 1,
+        output_field=models.IntegerField(null=True),
+        db_persist=True,
+        null=True,
+    )
+
 
 def process_non_nullable(
     x: Union[
@@ -669,6 +683,12 @@ def main() -> None:
     if not isinstance(comment.other_metadata, dict):
         print()  # type: ignore [unreachable]
 
+    process_non_nullable(comment.generated_field)
+    if isinstance(comment.nullable_generated_field, type(None)):
+        print(comment.nullable_generated_field)
+    if not isinstance(comment.generated_field, int):
+        print()  # type: ignore [unreachable]
+
 
 async def main_async() -> None:
     comment = await Comment.objects.aget(pk=123)