fix: ignore LOADING error to prevent out of sync order message

[dntam00]

Fix #718
Treat LOADING server is loading the dataset in memory error from redis server as a PONG reply.

[rueian]

Hi @dntam00,

Could you also duplicate the current test for NOPERM and change it to test the LOADING error:

rueidis/pipe_test.go

Lines 3243 to 3328 in 8897ec3

	t.Run("PubSub unsubReply failed", func(t *testing.T) {
	ctx := context.Background()
	p, mock, cancel, _ := setup(t, ClientOption{})
	commands := []Completed{
	builder.Sunsubscribe().Channel("1").Build(),
	builder.Sunsubscribe().Channel("2").Build(),
	builder.Get().Key("mk").Build(),
	}
	replies := [][]RedisMessage{
	{
	{ // proactive unsubscribe before user unsubscribe
	typ: '>',
	values: []RedisMessage{
	{typ: '+', string: "sunsubscribe"},
	{typ: '+', string: "a"},
	{typ: ':', integer: 0},
	},
	},
	{ // proactive unsubscribe before user unsubscribe
	typ: '>',
	values: []RedisMessage{
	{typ: '+', string: "sunsubscribe"},
	{typ: '+', string: "b"},
	{typ: ':', integer: 0},
	},
	},
	}, {
	// empty
	}, {
	{ // proactive unsubscribe after user unsubscribe
	typ: '>',
	values: []RedisMessage{
	{typ: '+', string: "sunsubscribe"},
	{typ: '_'},
	{typ: ':', integer: 0},
	},
	},
	{typ: '+', string: "mk"},
	},
	}
	p.background()
	// proactive unsubscribe before other commands
	mock.Expect().Reply(RedisMessage{ // proactive unsubscribe before user unsubscribe
	typ: '>',
	values: []RedisMessage{
	{typ: '+', string: "sunsubscribe"},
	{typ: '+', string: "0"},
	{typ: ':', integer: 0},
	},
	})
	time.Sleep(time.Millisecond * 100)
	for i, cmd1 := range commands {
	cmd2 := builder.Get().Key(strconv.Itoa(i)).Build()
	go func() {
	if cmd1.IsUnsub() {
	mock.Expect(cmd1.Commands()...).Expect(cmds.PingCmd.Commands()...).
	Reply(replies[i]...).
	Reply(RedisMessage{ // failed unsubReply
	typ: '-',
	string: "NOPERM User u has no permissions to run the 'ping' command",
	}).Expect(cmd2.Commands()...).ReplyString(strconv.Itoa(i))
	} else {
	mock.Expect(cmd1.Commands()...).Reply(replies[i]...).Expect(cmd2.Commands()...).ReplyString(strconv.Itoa(i))
	}
	}()
	if i == 2 {
	if v, err := p.Do(ctx, cmd1).ToString(); err != nil || v != "mk" {
	t.Fatalf("unexpected err %v", err)
	}
	} else {
	if err := p.Do(ctx, cmd1).Error(); err != nil {
	t.Fatalf("unexpected err %v", err)
	}
	}
	if v, err := p.Do(ctx, cmd2).ToString(); err != nil || v != strconv.Itoa(i) {
	t.Fatalf("unexpected val %v %v", v, err)
	}
	}
	cancel()
	})

[dntam00]

Hi @rueian,
I've updated the message of comment and a unit test.

[rueian]

Thank you @dntam00!