Bash script to delete branches that are merged and stale

branch_cleaner.sh

#!/usr/bin/env bash

# List of branches that never should be deleted
protected_branches=('v1.7' 'develop' 'master')

echo "Fetching all from remote to ensure everything is up to date..."
git fetch --all

expiration_date=$(date --date="7 days ago")

# The second parameter could be named `isLocal`
if $2; then
  branches=$(git --no-pager branch --merged "$1")
else
  branches=$(git --no-pager branch -r --merged "$1")
fi

for b in ${branches}; do
  last_commit_date=$(git show --format="%ci" "$b" | head -n 1)
  # shellcheck disable=SC2076
  if [[ ("$expiration_date" > "$last_commit_date") && (! " ${protected_branches[*]} " =~ " ${b} ") ]]; then
    echo "Are you sure you want to delete $b? (y/N)?"
    read -r choice
    case $choice in
    y | Y | yes | YES) (! $2 && git push origin --delete "$b") || ( $2 && git branch -d "$b" ) ;;
    n | N | no | NO) echo "Skipping $b..." ;;
    *) echo "no" ;;
    esac
  fi
done
echo "Done!"