1 files changed, 18 insertions, 0 deletions
diff --git a/internal/cli/run_test.go b/internal/cli/run_test.go
new file mode 100644
index 0000000..705fe29
--- /dev/null
+++ b/internal/cli/run_test.go
@@ -0,0 +1,18 @@
+package cli
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestRunTasks_InvalidParallel(t *testing.T) {
+	for _, parallel := range []int{0, -1, -100} {
+		err := runTasks("ignored.yaml", parallel, false)
+		if err == nil {
+			t.Fatalf("parallel=%d: expected error, got nil", parallel)
+		}
+		if !strings.Contains(err.Error(), "--parallel") {
+			t.Errorf("parallel=%d: error should mention --parallel flag, got: %v", parallel, err)
+		}
+	}
+}