1. Don't use case statements for dispatch anymore. This leads to a lot
of duplication, and makes the logic harder to follow.
2. Remove duplicated logic.
- For example, the `can_push_to_branch?` exists, but we also have a
different way of checking the same condition within `change_access_check`.
- This kind of duplication is removed, and the `can_push_to_branch?`
method is used in both places.
3. Move checks returning true/false to `UserAccess`.
- All public methods in `GitAccess` now return an instance of
`GitAccessStatus`. Previously, some methods would return
true/false as well, which was confusing.
- It makes sense for these kinds of checks to be at the level of a
user, so the `UserAccess` class was repurposed for this. The prior
`UserAccess.allowed?` classmethod is converted into an instance
method.
- All external uses of these checks have been migrated to use the
`UserAccess` class
4. Move the "change_access_check" into a separate class.
- Create the `GitAccess::ChangeAccessCheck` class to run these
checks, which are quite substantial.
- `ChangeAccessCheck` returns an instance of `GitAccessStatus` as
well.
5. Break out the boolean logic in `ChangeAccessCheck` into `if/else`
chains - this seems more readable.
6. I can understand that this might look like overkill for !4892, but I
think this is a good opportunity to clean it up.
- http://martinfowler.com/bliki/OpportunisticRefactoring.html
1. When a merge request is being merged, save the merge commit SHA in
the `in_progress_merge_commit_sha` database column.
2. The `pre-receive` hook looks for any locked (in progress) merge
request with `in_progress_merge_commit_sha` matching the `newrev` it
is passed.
3. If it finds a matching MR, the merge is legitimate.
4. Update `git_access_spec` to test the behaviour we added here. Also
refactored this spec a bit to make it easier to add more contexts / conditions.
If you attempt to push thousands of branches at once, the 60-second timeout
will occur because GitAccess checking does a lot of work to check if the
user has permission to push to a branch. This changes does two things:
1. Instead of making 1 DB query per branch push, use a memoized list of protected branches to check
2. Memoize what permissions the user has to perform on this project
On a test of 10,000 branch pushes, this prevents gitlab-shell from hitting the 60-second
timeout.
Closes#17225
Previously this method would directly receive the output of tag_name().
This method could either return a String or nil. In the previous setup
this would somehow magically work but because Rugged::TagCollection#[]
doesn't accept nil values it started to fail.
To work around this the elsif in change_access_check() assigns the
result of tag_name() to a local and then _only_ calls protected_tag?()
if the tag name is not nil. The extra parenthesis are put in place to
ensure that things are parsed correctly, without these the code would be
parsed as follows:
elsif tag_ref = (tag_name(ref) && protected_tag(tag_ref))
During runtime this would basically resolve to:
elsif tag_ref = (tag_name(ref) && protected_tag(nil))
This is because when you refer to the variable you're assigning _in_ the
assignment Ruby returns nil instead of raising an error.