MQTTnet/Source/MQTTnet.Tests/Server/Subscription_Identifier_Tests.cs

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System.Threading.Tasks;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using MQTTnet.Formatter;

namespace MQTTnet.Tests.Server;

// ReSharper disable InconsistentNaming
[TestClass]
public sealed class Subscription_Identifier_Tests : BaseTestClass
{
    [TestMethod]
    public async Task Server_Reports_Subscription_Identifiers_Supported()
    {
        using var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500);
        await testEnvironment.StartServer();

        var client = testEnvironment.CreateClient();
        var connectResult = await client.ConnectAsync(testEnvironment.ClientFactory.CreateClientOptionsBuilder()
            .WithProtocolVersion(MqttProtocolVersion.V500)
            .WithTcpServer("127.0.0.1", testEnvironment.ServerPort).Build());

        Assert.IsTrue(connectResult.SubscriptionIdentifiersAvailable);
    }

    [TestMethod]
    public async Task Subscribe_With_Subscription_Identifier()
    {
        using var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500);
        await testEnvironment.StartServer();

        var client1 = await testEnvironment.ConnectClient();
        var applicationMessageHandler = testEnvironment.CreateApplicationMessageHandler(client1);
        var topicFilter = testEnvironment.ClientFactory.CreateTopicFilterBuilder().WithTopic("Topic").Build();
        var subscribeOptions = testEnvironment.ClientFactory.CreateSubscribeOptionsBuilder().WithSubscriptionIdentifier(456).WithTopicFilter(topicFilter).Build();

        await client1.SubscribeAsync(subscribeOptions);
        await LongTestDelay();

        applicationMessageHandler.AssertReceivedCountEquals(0);

        // The client will publish a message where it is itself subscribing to.
        await client1.PublishStringAsync("Topic", "Payload", retain: true);
        await LongTestDelay();

        applicationMessageHandler.AssertReceivedCountEquals(1);

        Assert.Contains(456u, applicationMessageHandler.ReceivedEventArgs[0].ApplicationMessage.SubscriptionIdentifiers);
    }

    [TestMethod]
    public async Task Subscribe_With_Multiple_Subscription_Identifiers()
    {
        using var testEnvironment = CreateTestEnvironment(MqttProtocolVersion.V500);
        await testEnvironment.StartServer();

        var client1 = await testEnvironment.ConnectClient();
        var applicationMessageHandler = testEnvironment.CreateApplicationMessageHandler(client1);

        var topicFilter = testEnvironment.ClientFactory.CreateTopicFilterBuilder().WithTopic("Topic/A").Build();
        var subscribeOptions = testEnvironment.ClientFactory.CreateSubscribeOptionsBuilder().WithSubscriptionIdentifier(456).WithTopicFilter(topicFilter).Build();
        await client1.SubscribeAsync(subscribeOptions);

        await LongTestDelay();

        topicFilter = testEnvironment.ClientFactory.CreateTopicFilterBuilder().WithTopic("Topic/+").Build();
        subscribeOptions = testEnvironment.ClientFactory.CreateSubscribeOptionsBuilder().WithSubscriptionIdentifier(789).WithTopicFilter(topicFilter).Build();
        await client1.SubscribeAsync(subscribeOptions);

        await LongTestDelay();

        applicationMessageHandler.AssertReceivedCountEquals(0);

        // The client will publish a message where it is itself subscribing to.
        await client1.PublishStringAsync("Topic/A", "Payload", retain: true);
        await LongTestDelay();

        applicationMessageHandler.AssertReceivedCountEquals(1);

        Assert.Contains(456u, applicationMessageHandler.ReceivedEventArgs[0].ApplicationMessage.SubscriptionIdentifiers);
        Assert.Contains(789u, applicationMessageHandler.ReceivedEventArgs[0].ApplicationMessage.SubscriptionIdentifiers);
    }
}