Return from get_deleted_objects-method of ModelAdmin

[golgor]

Bug report

What's wrong

When we delete a certain object, we also want to delete some related objects and we want this to be visible in the Delete Confirmation View.

I got some typing issues regarding an override I did for get_deleted_objects(self, objs, request) in a subclass to admin.ModelAdmin.

Looking at the Django documentation for this method it is said to return tuple[list[str], dict[str, int], set[str], list[str]].

I also verified this in a debug session where the deleted_objects value was: 'Parameter set: <a href="/admin/onboard/parameterset/341/change/">341</a>'.

However, in django_stubs.contrib.admin.options.ModelAdmin.get_deleted_objects I see the the deleted_objects is typed as list[Model]. The full return type is specified as tuple[list[Model], dict[str, int], set[str], list[str]].

I rely on this being a list[str] as I append strings to this list using django.utils.html.format_html, which fails with the current definition using a list[Model].

Just some example code to easier understand the issue (Not verified if this exact code raises the issue):

class TestAdmin(admin.ModelAdmin):
    def get_deleted_objects(self, objs, request) -> tuple[list[str], dict[str, int], set[str], list[str]]:
        deleted_objects, model_count, perms_needed, protected = super().get_deleted_objects(objs, request)
        for obj in objs:
            deleted_objects.append(
                    format_html(
                        HTML_TEMPLATE,
                        obj.titleid,
                        obj.titleid,
                    )
            )
    return deleted_objects, model_count, perms_needed, protected

This would return a mypy-error:

Return type "tuple[list[str], dict[str, int], set[str], list[str]]" of "get_deleted_objects" incompatible with return type "tuple[list[Model], dict[str, int], set[str], list[str]]" in supertype "ModelAdmin"

Just changing it to list[Model] doesn't work in this case, as the I get:

Argument 1 to "append" of "list" has incompatible type "SafeString"; expected "Model"

How is that should be

The return type of admin.ModelAdmin.get_deleted_objects should be changed from:

def get_deleted_objects(
    self, objs: Sequence[_ModelT] | QuerySet[_ModelT], request: HttpRequest
) -> tuple[list[Model], dict[str, int], set[str], list[str]]: ...

def get_deleted_objects(
    self, objs: Sequence[_ModelT] | QuerySet[_ModelT], request: HttpRequest
) -> tuple[list[str], dict[str, int], set[str], list[str]]: ...

System information

• OS: Fedora Linux 38 (KDE Plasma) @ 6.5.9-200.fc38.x86_64 (64-bit)
• python version: 3.11.6
• django version: 4.2.7
• mypy version: 1.6.1
• django-stubs version: 4.2.6
• django-stubs-ext version: 4.2.5