update-pr

Update PR

Sync the current branch with its base branch: fetch → rebase (or merge) → resolve conflicts → push.

Step 1: Detect Base Branch and Method

BASE=$(gh pr view --json baseRefName --jq '.baseRefName' 2>/dev/null)
if [ -z "$BASE" ]; then
  BASE=$(git rev-parse --abbrev-ref origin/HEAD | sed 's|origin/||')
fi

Method: Use rebase by default. Switch to merge only if the user explicitly says "merge" or passes --merge.

Tell the user: "Updating $(git branch --show-current) from $BASE (rebase)." — or "(merge)" if merge was requested.

Step 2: Fetch Latest

git fetch origin "$BASE"

Check if already up to date:

BEHIND=$(git rev-list HEAD..origin/"$BASE" --count)

If BEHIND is 0, tell the user "Already up to date with $BASE." and stop.

Step 3: Rebase (default)

git rebase origin/"$BASE"

If rebase succeeds: proceed to Step 5.

If rebase hits conflicts: proceed to Step 4.

Merge (when explicitly requested)

git merge origin/"$BASE"

If merge succeeds: proceed to Step 5.

If merge hits conflicts: proceed to Step 4 (merge variant).

Step 4: Resolve Conflicts

List conflicted files:

git diff --name-only --diff-filter=U

For each conflicted file, resolve the conflict markers (<<<<<<<, =======, >>>>>>>). Favor the PR branch's intent unless the base branch changes must win (e.g., schema migrations, config values).

After resolving each file:

git add <file>

Continue rebase:

GIT_EDITOR=true git rebase --continue

Repeat for each commit if there are multiple conflicts. To abort: git rebase --abort.

Continue merge:

GIT_EDITOR=true git merge --continue

To abort: git merge --abort.

Tell the user "Aborted. Branch is unchanged." on abort.

Step 5: Push

Rebase rewrites history — a force-push is required and expected:

git push --force-with-lease

After a merge, a regular push suffices:

git push

Never use bare --force.

Step 6: Report

Branch updated from $BASE via rebase. Replayed N commit(s). [PR link if available]

Or for merge:

Branch updated from $BASE via merge. [PR link if available]

List any files where conflicts were resolved.

Error Handling

• Not on a branch / detached HEAD — "You're in a detached HEAD state. Check out a branch first."
• Uncommitted changes — Run git stash first, complete the operation, then git stash pop. Tell the user what was stashed.
• gh not available — Use the repo default branch as the base. Warn: "No PR found; using default branch $BASE."
• Merge conflict in a generated file — Prefer the base branch version and re-run the generation step if one exists.