Delete Stale Branches

delete-stale-branches.sh

#!/usr/bin/env bash
while getopts "d" opt; do
  case $opt in
    d) dryRunOpt="--dry-run";;
  esac
done

UPSTREAM=origin
BASE=main
UPSTREAM_BASE="$UPSTREAM/$BASE"
STALE_AGE="365 days"
REVIEW_AGE="180 days"

# prune local "cache" of remote branches first:
git fetch --prune $UPSTREAM
# delete merged to $UPSTREAM_BASE branches:
mergedBranches=$(git branch -r --merged $UPSTREAM_BASE | grep "^  $UPSTREAM/" | cut -d/ -f2- | grep -v -e "^$BASE$" -e "^HEAD -> $UPSTREAM_BASE$")
if [ -n "${mergedBranches}" ]; then
  echo -e "\033[0;32mDeleting merged branches...\033[0m"
  git push $dryRunOpt --delete $UPSTREAM ${mergedBranches}
fi
# delete branches with last (cherry picked) commit older than $STALE_AGE:
echo -e "\033[0;32mSearching for stale branches (older than $STALE_AGE)...\033[0m"
staleTimestamp=$(date -d "now - $STALE_AGE" +"%s")
maybeStaleTimestamp=$(date -d "now - $REVIEW_AGE" +"%s")
notMergedBranches=$(git branch -r --no-merged $UPSTREAM_BASE | grep "^  $UPSTREAM/")
branchesToDelete=""
branchesToReview=""
for branch in ${notMergedBranches}; do
  lastCommitInfo=$(git cherry $UPSTREAM_BASE ${branch} | grep -v "^-" | cut -d" " -f2 | xargs git show --format="%H|%ct|%cr|%an" --quiet | grep -v "^$(git rev-parse HEAD)" | tail -1)
  lastCommitTimestamp=$(echo "${lastCommitInfo}" | cut -d"|" -f2)
  # use this logic because lastCommitTimestamp can be null
  if [[ ! -z "${lastCommitTimestamp}" ]] && [[ ${lastCommitTimestamp} -lt ${staleTimestamp} ]]; then
    branchesToDelete+=" ${branch#$UPSTREAM/}"
  elif [[ ${lastCommitTimestamp} -lt ${maybeStaleTimestamp} ]]; then
    branchesToReview+="${branch#$UPSTREAM/}|${lastCommitInfo}"$'\n'
  fi
  echo -n .
done
echo # for new line after dots
if [[ -n "${branchesToDelete}" ]]; then
  echo -e "\033[0;32mDeleting stale branches...\033[0m"
  git push $dryRunOpt --delete $UPSTREAM ${branchesToDelete}
else
  echo -e "\033[0;32mNo stale branches...\033[0m"
fi
echo -e "\033[1;33mBranches to review (older than $REVIEW_AGE and may be stale):\033[0m"
echo "${branchesToReview}" | sort -t"|" -k5 | awk -F"|" 'NF {print $5 " changed branch \"" $1 "\" in project \"'${PWD##*/}'\" " $4}'

This revision makes it easier to change the upstream and base branch names, as well as the stale and review ages. Logging is improved and the possibility of deleting a branch with null commit timestamp is avoided.