In a triangular workflow the branch that you're pulling from is not the same as
the one that you are pushing to. For example, some people find it useful to set
the upstream branch to origin/master so that pulling effectively rebases onto
master, and set the push.default git config to "current" so that "feature"
pushes to origin/feature.
Another example is a fork-based workflow where "feature" has upstream set to
upstream/main, and the repo has remote.pushDefault set to "origin", so pushing
on "feature" pushes to origin/feature.
This commit adds new fields to models.Branch that store the ahead/behind
information against the push branch; for the "normal" workflow where you pull
and push from/to the upstream branch, AheadForPush/BehindForPush will be the
same as AheadForPull/BehindForPull.
The model will be used for logic, so the full hash is needed there; a shortened
hash of 8 characters might be too short to be unique in very large repos. If
some view wants to display a shortened hash, it should truncate it at
presentation time.
We've been sometimes using lo and sometimes using my slices package, and we need to pick one
for consistency. Lo is more extensive and better maintained so we're going with that.
My slices package was a superset of go's own slices package so in some places I've just used
the official one (the methods were just wrappers anyway).
I've also moved the remaining methods into the utils package.
This fixes pkg/integration/tests/worktree/rebase.go which was failing on old git versions due to a difference in
order of branches that don't have recency values
test: add an integration test for checkout branch by name
fix: fix full ref name of detached head
refactor: refactor current branch loader
chore: use field name explicitly
