diff --git a/claudetool/codereview/testdata/generate_no_changes.txtar b/claudetool/codereview/testdata/generate_no_changes.txtar
new file mode 100644
index 0000000..e38d7e9
--- /dev/null
+++ b/claudetool/codereview/testdata/generate_no_changes.txtar
@@ -0,0 +1,24 @@
+Test go generate with no changes in mechanical checks
+
+-- go.mod --
+module sketch.dev
+
+go 1.23
+
+-- .commit --
+Initial commit
+
+-- main.go --
+package main
+
+//go:generate echo "No-op generation"
+
+func main() {
+	println("Hello, world!")
+}
+
+-- .commit --
+Commit with no-op go generate directive
+
+-- .run_test --
+OK