From d9c4f824d2cf6d3768a618b044360c7859b86c58 Mon Sep 17 00:00:00 2001
From: Tom Alexander <tom@fizz.buzz>
Date: Wed, 6 May 2026 09:56:18 -0400
Subject: [PATCH] Add git_find_merged_branches script.

---
 nix/configuration/roles/base/default.nix               |  3 +++
 .../roles/base/files/git_find_merged_branches.bash     | 10 ++++++++++
 2 files changed, 13 insertions(+)
 create mode 100644 nix/configuration/roles/base/files/git_find_merged_branches.bash

diff --git a/nix/configuration/roles/base/default.nix b/nix/configuration/roles/base/default.nix
index b42cfed2..93ba43d2 100644
--- a/nix/configuration/roles/base/default.nix
+++ b/nix/configuration/roles/base/default.nix
@@ -15,6 +15,9 @@ let
     patchScriptBin "cleanup_temporary_files" (builtins.readFile ./files/cleanup_temporary_files.bash)
   );
   decode_jwt = (patchScriptBin "decode_jwt" (builtins.readFile ./files/decode_jwt.bash));
+  git_find_merged_branches = (
+    patchScriptBin "git_find_merged_branches" (builtins.readFile ./files/git_find_merged_branches.bash)
+  );
   alias_rga = pkgs.writeShellScriptBin "rga" ''
     exec ${pkgs.ripgrep}/bin/rg -uuu "''${@}"
   '';
diff --git a/nix/configuration/roles/base/files/git_find_merged_branches.bash b/nix/configuration/roles/base/files/git_find_merged_branches.bash
new file mode 100644
index 00000000..f794b857
--- /dev/null
+++ b/nix/configuration/roles/base/files/git_find_merged_branches.bash
@@ -0,0 +1,10 @@
+#!/usr/bin/env bash
+#
+# Find local branches that have been merged
+set -euo pipefail
+IFS=$'\n\t'
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+: ${MAIN_BRANCH:="main"}
+
+git checkout -q ${MAIN_BRANCH} && git for-each-ref refs/heads/ "--format=%(refname:short)" | while read branch; do mergeBase=$(git merge-base ${MAIN_BRANCH} $branch) && [[ $(git cherry ${MAIN_BRANCH} $(git commit-tree $(git rev-parse "$branch^{tree}") -p $mergeBase -m _)) == "-"* ]] && echo "$branch"; done