git-smart-branch

#!/usr/bin/env bash
set -euo pipefail

latest_branch=$(
  git for-each-ref refs/heads \
    --sort=-committerdate \
    --format='%(refname:short)' \
    | grep -E '.+/.+-[0-9]+$' \
    | head -n 1 || true
)

if [[ -z "$latest_branch" ]]; then
  echo "No matching branch pattern detected."
  exit 1
fi

if [[ "$latest_branch" =~ ^(.+/[^/]+-)([0-9]+)$ ]]; then
  prefix="${BASH_REMATCH[1]}"
  number="${BASH_REMATCH[2]}"
  width="${#number}"

  next_number=$((10#$number + 1))
  next_number_padded="$(printf "%0${width}d" "$next_number")"

  new_branch="${prefix}${next_number_padded}"

  echo "Latest branch: $latest_branch"
  echo "Creating: $new_branch"

  git checkout -b "$new_branch"

  echo "Done."
else
  echo "Detected branch does not match expected pattern."
  exit 1
fi