add test suite

internal/tui/run_test.go

@@ -0,0 +1,27 @@
+package tui
+
+import (
+	"testing"
+)
+
+func TestContainsOption_present(t *testing.T) {
+	opts := []string{"force", "vertical-slices", "omit-test"}
+	if !containsOption(opts, "vertical-slices") {
+		t.Error("containsOption failed to find present option")
+	}
+}
+
+func TestContainsOption_absent(t *testing.T) {
+	opts := []string{"force", "vertical-slices"}
+	if containsOption(opts, "omit-test") {
+		t.Error("containsOption found absent option")
+	}
+}
+
+func TestDefaultOutputDir_stable(t *testing.T) {
+	out1 := defaultOutputDir()
+	out2 := defaultOutputDir()
+	if out1 != out2 {
+		t.Error("defaultOutputDir should be deterministic for same cwd")
+	}
+}