err = os.WriteFile(fileName, []byte{1, 2, 3}, 0555)
	if err != nil {
		t.Fatalf("unable to write test file %#v", err)
	}

	ch := make(chan interface{}, 1)
	lw := newSourceFile(fileName, "localhost", time.Millisecond, ch)
	err = lw.listConfig()
	if err == nil {
		t.Fatalf("expected error, got nil")
	}
	expectEmptyChannel(t, ch)
}

func TestExtractFromEmptyDir(t *testing.T) {