update-mine

#!/usr/bin/env bash

set -euo pipefail

# Initialize flags
debug=false
all_branches=false

SCRIPT_NAME=$(basename "$0")

# Function to display usage information
usage() {
	local exit_code=${1:-0}
	cat <<EOF
Usage: $SCRIPT_NAME [--debug] [--all] <reference_branch>

By default, updates branches with open pull requests authored by you by:
1. Checking out the branch.
2. Merging the specified reference branch into it.
3. Pushing the updated branch to the remote.

Options:
  --debug   Enable debugging output.
  --all     Update ALL non-protected branches on the remote (not just yours).
            Use with caution - this may update branches owned by others.
  --help    Show this help message and exit.

Arguments:
  <reference_branch>  The branch to merge into your branches (e.g., 'main').

Examples:
  $SCRIPT_NAME main
  $SCRIPT_NAME --debug main
  $SCRIPT_NAME --all main
  $SCRIPT_NAME --debug --all main
EOF
	exit "$exit_code"
}

# Parse command-line arguments
reference_branch=""
while [[ $# -gt 0 ]]; do
	case "$1" in
	--debug)
		debug=true
		shift
		;;
	--all)
		all_branches=true
		shift
		;;
	--help)
		usage
		;;
	-*)
		echo "Unknown option: $1" >&2
		usage 1
		;;
	*)
		if [ -z "$reference_branch" ]; then
			reference_branch="$1"
		else
			echo "Error: Multiple reference branches specified: '$reference_branch' and '$1'" >&2
			usage 1
		fi
		shift
		;;
	esac
done

# Validate that a reference branch was provided
if [ -z "$reference_branch" ]; then
	echo "Error: Missing <reference_branch> argument." >&2
	echo "Use --help for usage information." >&2
	exit 1
fi

# Enable debugging if --debug flag is set
if [ "$debug" = true ]; then
	set -x
fi

# Ensure we are inside a Git repository
if ! git rev-parse --is-inside-work-tree >/dev/null 2>&1; then
	echo "Error: Not inside a Git repository." >&2
	exit 1
fi

# Ensure gh CLI is installed
if ! command -v gh >/dev/null 2>&1; then
	echo "Error: 'gh' (GitHub CLI) is required but not installed." >&2
	echo "Install it from: https://cli.github.com/" >&2
	exit 1
fi

# Fetch latest remote branches to avoid using stale references
git remote update >/dev/null 2>&1

# Determine the list of branches to update
if [ "$all_branches" = true ]; then
	echo "Fetching all non-protected branches (use with caution)..."
	if ! branches=$(gh api repos/:owner/:repo/branches --paginate --jq '.[] | select(.protected == false) | .name' 2>&1); then
		echo "Error: Failed to fetch branches from GitHub API." >&2
		echo "$branches" >&2
		exit 1
	fi
else
	echo "Fetching branches with open PRs authored by you..."
	if ! branches=$(gh pr list --author "@me" --state open --json headRefName -q '.[].headRefName' 2>&1); then
		echo "Error: Failed to list PRs. Is 'gh' installed and authenticated?" >&2
		echo "$branches" >&2
		exit 1
	fi
fi

# Iterate through branches and update them
if [ -z "$branches" ]; then
	echo "No branches found."
	exit 0
fi

while read -r branch; do
	# Skip empty lines
	[ -z "$branch" ] && continue

	echo "Processing branch: $branch"

	# Checkout the branch (create tracking branch if it only exists on remote)
	if ! git checkout "$branch" 2>/dev/null; then
		if ! git switch --track "origin/$branch" 2>/dev/null; then
			echo "Error: Failed to checkout branch $branch. Skipping..."
			continue
		fi
	fi

	# Merge the reference branch into the current branch
	if ! mergewith "$reference_branch"; then
		echo "Error: Failed to merge $reference_branch into $branch. Skipping..."
		git merge --abort >/dev/null 2>&1
		continue
	fi

	# Push the updated branch
	if git push origin "$branch"; then
		echo "Successfully updated and pushed branch: $branch"
	else
		echo "Error: Failed to push branch $branch. Skipping..."
	fi
done <<<"$branches"