Clean up local git branches that have been deleted on remote

git-clean-merged

#! /bin/bash

# deletes local branches that have been deleted on remote
# this version requires that `git fetch -p` is used to prune remote branches from your local repo

declare force

force=false

if [ $# -gt 0 ]; then
  case "$1" in
    --force|-D)
      force=true;;
    *)
      echo "Unknown argument"
      exit 1;;
  esac
fi


confirm()
{
  local response

  # call with a prompt string or use a default
  read -r -p "${1:-Are you sure? [y/N]} " response

  case "${response}" in
    [yY][eE][sS]|[yY])
      true;;
    *)
      false;;
  esac
}

merged_branches()
{
  # Deletes based on upstream branch deletion instead of actual merges
  git branch -vv | awk '!/^\*/ && /: gone]/ { print $1 }'
}

declare -a merged
# shellcheck disable=SC2207
merged=($(merged_branches))

if (( !${#merged[@]} )); then
  echo "No merged branches to delete."
  exit 0
fi

echo "This will delete the follow branches..."

for branch in "${merged[@]}"; do
  echo "  ${branch}"
done

echo

if ! confirm "Would you like to continue? [y/N]"; then
  echo "aborted"
  exit 1
fi

if $force; then
  git branch -D "${merged[@]}"
else
  git branch -d "${merged[@]}"
fi

echo
echo "Done!"