git smart pruner

git-smart-prune.sh

#!/usr/bin/env bash

# Use this when Github bugs out and refuses to delete your
# head branches after a PR got merged, even though you
# have enabled that behaviour in your fork.

set -euo pipefail

source $(dirname "$0")/src/lib.sh

contains() {
  grep "$1" >/dev/null 2>&1
}

# determine source repo
upstream=
origin=
if git remote | contains upstream; then
  upstream=upstream
  origin=origin
else
  upstream=origin
  origin=origin
fi

source="$(git remote get-url $upstream)"

num=25
echo "Finding the most recent $num merged PRs…"
mergedBranches="$(gh pr list --repo "$source" --author "@me" --limit $num --state merged --json headRefName | jq -r '.[].headRefName')"

echo "Listing branches in $origin…"
myBranches="$(git ls-remote --heads "$origin")"

prune=false
for mergedBranch in $mergedBranches; do
  if echo "$myBranches" | contains "refs/heads/$mergedBranch"; then
    echo "Deleting remote branch $mergedBranch…"
    git push "$origin" --quiet --delete "$mergedBranch"
    prune=true
  fi
done

if $prune; then
  git remote prune "$origin"
fi