add ForeignKey

django-stubs/db/models/__init__.pyi

@@ -7,3 +7,5 @@ from .fields import (AutoField as AutoField,
                      Field as Field,
                      SlugField as SlugField,
                      TextField as TextField)
+from .fields.related import (ForeignKey as ForeignKey)
+from .deletion import CASCADE as CASCADE

django-stubs/db/models/deletion.pyi

@@ -0,0 +1,2 @@
+def CASCADE(collector, field, sub_objs, using):
+    ...

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

@@ -0,0 +1,14 @@
+from typing import Type, Union, TypeVar, Any, Generic
+
+from django.db import models
+from django.db.models import Field
+
+_T = TypeVar('_T', bound=models.Model)
+
+
+class ForeignKey(Field, Generic[_T]):
+    def __init__(self,
+                 to: Union[Type[_T], str],
+                 on_delete: Any,
+                 **kwargs): ...
+    def __get__(self, instance, owner) -> _T: ...

test/test-data/check-model-relations.test

@@ -0,0 +1,14 @@
+[case testForeignKeyWithClass]
+from django.db import models
+
+class User(models.Model):
+    pass
+
+class Profile(models.Model):
+    user = models.ForeignKey(to=User, on_delete=models.CASCADE)
+
+profile = Profile()
+reveal_type(profile.user)  # E: Revealed type is 'main.User*'
+[out]
+
+

test/testdjango.py

@@ -15,7 +15,8 @@ MYPY_INI_PATH = ROOT_DIR / 'test' / 'plugins.ini'
 class DjangoTestSuite(DataSuite):
     files = [
         'check-model-fields.test',
-        'check-postgres-fields.test'
+        'check-postgres-fields.test',
+        'check-model-relations.test'
     ]
     data_prefix = str(TEST_DATA_DIR)