Prune remote branches

prune-remote-branches.sh

#!/bin/bash

# Usage:
# bash prune-remote-branches.sh --all-before 2023-08-01 --none-after 2021-03-01 --force

# Default values for flags
CENTRAL_BRANCH="master"
DRY_RUN=true

# Parse command line arguments
while [[ $# -gt 0 ]]; do
  case "$1" in
    -c|--central-branch)
      CENTRAL_BRANCH="$2"
      shift
      ;;
    -b|--all-before)
      ALL_BEFORE_DATE="$2"
      shift
      ;;
    -a|--none-after)
      NONE_AFTER_DATE="$2"
      shift
      ;;
    -f|--force)
      DRY_RUN=false
      ;;
    *)
      echo "Invalid option: $1"
      exit 1
      ;;
esac
  shift
done

if [[ -z "$ALL_BEFORE_DATE" && -z "$NONE_AFTER_DATE" ]]; then
  echo "Must set either --all-before or --non-after"
  exit 1
fi

get_all_remote_branches() {
  branch_names=$(git br -r | grep -v " -> " | sed 's/^[[:space:]]*origin\///' | sort)
  for branch_name in "${branch_names[@]}"; do
    if [[ "$branch_name" != "CENTRAL_BRANCH" ]]; then
      echo "$branch_name"
    fi
  done
}

for BRANCH_NAME in $(get_all_remote_branches); do
  if [[ "$BRANCH_NAME" == "$CENTRAL_BRANCH" ]]; then
    continue
  fi

  LAST_COMMIT=$(git rev-list -n 1 "origin/$BRANCH_NAME")
  LAST_COMMIT_DATE=$(git show -s --format=%cd --date=format:'%Y-%m-%d' "$LAST_COMMIT")
  
  if [[ -n "$NONE_AFTER_DATE" && "$LAST_COMMIT_DATE" > "$NONE_AFTER_DATE" ]]; then
    continue
  fi

  should_delete_branch=false
  MERGE_BASE=$(git merge-base "origin/$BRANCH_NAME" "origin/$CENTRAL_BRANCH")
  if [[ "$LAST_COMMIT" == "$MERGE_BASE" ]]; then
    echo "[$BRANCH_NAME]: Merged to $CENTRAL_BRANCH. Last commit: $LAST_COMMIT - $LAST_COMMIT_DATE"
    should_delete_branch=true
  elif [[ -n "$ALL_BEFORE_DATE" && "$LAST_COMMIT_DATE" < "$ALL_BEFORE_DATE" ]]; then
    echo "[$BRANCH_NAME]: Stale. Last commit: $LAST_COMMIT - $LAST_COMMIT_DATE"
    should_delete_branch=true
  fi

  if [ "$DRY_RUN" = false ] && [ "$should_delete_branch" = true ]; then
    git push origin --delete "$BRANCH_NAME"
  fi
done