preen
Review a PR
preen pr 42 # review PR 42
preen pr # the PR opened from the current branch
With no number, gh resolves the pull request opened from the branch you are
standing on. That is the common case: you are on the branch, you want to look
at it.
It is the same picker as preen diff: file list on the left,
delta diff on the right, ctrl-s to flip between side-by-side and inline,
enter for the full file in a pager. The border label carries the PR number
and title so you can tell one review from another.
What it needs
- the
ghCLI - a logged-in account —
gh auth login
preen checks both before doing anything, and says which one is missing rather
than failing halfway through.
It never touches your working tree
preen pr is read-only. The diff comes over the GitHub API, so there is:
- no checkout
- no fetch
- no branch switch
- no stash
Your working tree, your index and your current branch are left exactly as they were. You can review a PR in the middle of your own half-finished work and nothing you have gets moved or hidden.
One exception, and it is yours to trigger: ctrl-e opens the file in
$EDITOR. It is handed the PR's path, so what opens is your copy of that
path — or an empty new file, if the PR adds one you do not have. Nothing is
written unless you write it, but this is the one key in pr mode that touches
your checkout at all.
This is the difference from gh pr checkout, which is the usual way to read a
PR locally and which does move you.
One diff fetch, not one per file
Starting a review costs four gh calls, whatever the size of the PR:
gh auth status, gh pr view to resolve the number and title, and gh pr diff twice — once for the diff itself and once for --name-only to build the
file list.
The diff is then cached in a temporary directory for the life of the run,
and each preview slices its own file out of that cache with a small awk
pass. That is the part that scales: a 90-file pull request costs the same
four calls as a one-file one, and arrow-keying down the list is instant
instead of waiting on the API at every step.
The cache is a scratch directory under $TMPDIR, created on start and removed
when preen exits.
How a file is sliced out
Every file in a unified diff opens with a header line:
diff --git a/PATH b/PATH
The slice matches on the b/PATH tail, not on the path anywhere in the
line. A path that itself contains b/ would otherwise split in the wrong
place and show you the wrong file.
When it cannot find a PR
Run preen pr on a branch with no open pull request and gh says so; preen
passes that first line straight through rather than burying it. The fix is
usually to name the number instead:
preen pr 42
Related
git diff | preendoes the same rendering for any diff you can produce, includinggh pr diff 42 | preen— that gives you one long scroll instead of a per-file picker.- Worktrees is the same read-only idea applied to local branches an agent has been working in.