Add script to find merged branches when squashed on merge

git-find-merged

@@ -0,0 +1,17 @@
+#!/bin/bash
+# Find local branches that have been squash-merged into a target branch.
+# Usage: git-find-merged [target-branch]
+# Default target branch: main
+
+target="${1:-main}"
+
+git for-each-ref refs/heads/ --format='%(refname:short)' | while read branch; do
+  [[ "$branch" == "$target" ]] && continue
+  merge_base=$(git merge-base "$target" "$branch" 2>/dev/null) || continue
+  tree=$(git rev-parse "$branch^{tree}" 2>/dev/null) || continue
+  squash_commit=$(git commit-tree "$tree" -p "$merge_base" -m "test" 2>/dev/null) || continue
+  cherry_result=$(git cherry "$target" "$squash_commit" 2>/dev/null)
+  if [[ "$cherry_result" == "-"* ]]; then
+    echo "$branch"
+  fi
+done