Refactor git lookup

[florian-jaeger]

No description provided.

[adammccartney]

So it felt like I made a little bit of progress with this over the past couple of days, today I pushed sha 5163fec with the most recent updates. Since making specific dataclasses for the various types of git repos, I had some further thoughts on how to deal with the very many calls to os.path.join(...) that are getting made all over the place still.

I was wondering what would be the implication of implementing __repr__ methods on each of our GitRepo classes that we now have. This would mean that we can simple call os.path(str(git_repo)) when we want to create the specific path. Instead of having to always call os.path.join(git_repo.root, git_repo.lecture_code, git_repo.assignment_id). I pushed a quick edit of these classes and they now look like this:

Grader-Service/grader_service/grader_service/handlers/git/server.py

Lines 29 to 64 in a21e635

	@dataclass
	class GitRepoBasePath:
	root: str
	lecture_code: str
	assignment_id: int
	repo_type: str
	def __repr__(self):
	return f"""{self.root!r}/{self.lecture_code!r}/\
	{self.assignment_id!r}/{self.repo_type!r}"""
	class GitRepoSubmissionExtendedPath(GitRepoBasePath):
	def __init__(self, root: str, lecture_code: str,
	assignment_id: int, repo_type: str,
	submission_id: int):
	super().__init__(root, lecture_code, assignment_id, repo_type)
	self.submission_id = submission_id
	def __repr__(self):
	return f"""{self.root!r}/{self.lecture_code!r}/{self.assignment_id!r}/\
	{self.repo_type!r}/{self.submission_id!r}"""
	class GitRepoUserExtendedPath(GitRepoBasePath):
	def __init__(self, root: str, lecture_code: str,
	assignment_id: int, repo_type: str,
	username: str):
	super().__init__(root, lecture_code, assignment_id, repo_type)
	self.username = username
	def __repr__(self):
	return f"""{self.root!r}/{self.lecture_code!r}/{self.assignment_id!r}/\
	{self.repo_type}/{self.username!r}"""

As I mentioned in the commit, I haven't tested them yet and also somehow I am not convinced that I've got the representation of the paths quite right - my inclusion of the self.root is possibly superfluous. I think the actually creation of the paths on the system is being done by GraderBaseHandler.construct_git_dir(). I'm not sure, but this seems to me that it might be happier living with the other git specific methods in GitBaseHandler. It also appears as if we are stripping and then re-appending the git pathlet in between receiving the request and setting up the path on our filesystem.