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) {
	dirName, err := mkTempDir("file-test")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	defer removeAll(dirName, t)

	ch := make(chan interface{}, 1)