Deletes all stale branches on GitHub (or Enterprise Server) using gh CLI and jq

delete-stale-branches.fish

set owner "siketyan"
set repo "foobar"
set last_committed_before "2023-03-01"

for name in (gh api "repos/$owner/$repo/branches?per_page=100" | jq -r .[].name)
    echo "Checking $name"
    set stale (gh api "repos/$owner/$repo/branches/$name" | jq -r "select(.commit.commit.committer.date < $last_committed_before) | .name")
    if test -n "$stale"
        echo "Branch $stale is stale, deleting"
        gh api -X DELETE "repos/$owner/$repo/git/refs/heads/$stale"
    end
end