Return type mismatch in repo.submodule_update()

[extrwi]

Hello everyone! repo.submodule_update is annotated to return an Iterator[Submodule] (and I hoped it might return an iterator of modified modules or something similar).

GitPython/git/repo/base.py

Lines 523 to 531 in ba5c10d

	def submodule_update(self, *args: Any, **kwargs: Any) -> Iterator[Submodule]:
	"""Update the submodules, keeping the repository consistent as it will
	take the previous state into consideration.
	:note:
	For more information, please see the documentation of
	:meth:`RootModule.update <git.objects.submodule.root.RootModule.update>`.
	"""
	return RootModule(self).update(*args, **kwargs)

However, RootModule.update just returns self (type RootModule):

GitPython/git/objects/submodule/root.py

Lines 79 to 90 in ba5c10d

	def update( # type: ignore[override]
	self,
	previous_commit: Union[Commit_ish, str, None] = None,
	recursive: bool = True,
	force_remove: bool = False,
	init: bool = True,
	to_latest_revision: bool = False,
	progress: Union[None, "RootUpdateProgress"] = None,
	dry_run: bool = False,
	force_reset: bool = False,
	keep_going: bool = False,
	) -> "RootModule":

[Byron]

Thanks for reporting.

Unfortunately the implementation uses a strange and unnecessary OOM abstraction which makes everything harder to understand. This is probably also the reason the type is off here.

The best fix would certainly be if there was no RootSubmodule at all. But maybe there is also a simple type-based fix that already helps.

[extrwi]

To me it looks like the return type might have been introduced as a copy and paste bug from the method right above it:

GitPython/git/repo/base.py

Line 512 in ba5c10d

def iter_submodules(self, *args: Any, **kwargs: Any) -> Iterator[Submodule]:

The most important problem with the type mismatch is that the value returned by update is not iterable at all. :-)

[extrwi]

Please merge my PR if you agree or just close it otherwise. ;-)