Added queue service consuming tests.

Author: Anton Vorontsov

src/RabbitMQ.Client.Core.DependencyInjection/Services/QueueService.cs

@@ -16,7 +16,7 @@ namespace RabbitMQ.Client.Core.DependencyInjection.Services
     /// <summary>
     /// Implementation of the custom RabbitMQ queue service.
     /// </summary>
-    internal sealed class QueueService : IQueueService, IDisposable
+    public sealed class QueueService : IQueueService, IDisposable
     {
         public IConnection Connection { get; private set; }
 
@@ -335,7 +335,7 @@ void ConfigureConnectionInfrastructure(RabbitMqConnectionOptionsContainer option
         void StartClient()
         {
             var deadLetterExchanges = _exchanges
-                .Where(x => !string.IsNullOrEmpty(x.Options.DeadLetterExchange))
+                .Where(x => !string.IsNullOrEmpty(x.Options?.DeadLetterExchange))
                 .Select(x => x.Options.DeadLetterExchange)
                 .Distinct()
                 .ToList();

tests/RabbitMQ.Client.Core.DependencyInjection.Tests/UnitTests/QueueServiceConsumerTests.cs

@@ -0,0 +1,91 @@
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Microsoft.Extensions.Logging;
+using Moq;
+using RabbitMQ.Client.Core.DependencyInjection.Configuration;
+using RabbitMQ.Client.Core.DependencyInjection.Models;
+using RabbitMQ.Client.Core.DependencyInjection.Services;
+using RabbitMQ.Client.Events;
+using Xunit;
+
+namespace RabbitMQ.Client.Core.DependencyInjection.Tests.UnitTests
+{
+    public class QueueServiceConsumerTests
+    {
+        [Theory]
+        [InlineData(1)]
+        [InlineData(5)]
+        [InlineData(10)]
+        [InlineData(15)]
+        [InlineData(20)]
+        [InlineData(25)]
+        public async Task ShouldProperlyConsumeMessages(int numberOfMessages)
+        {
+            var channelMock = new Mock<IModel>();
+            var connectionMock = new Mock<IConnection>();
+            connectionMock.Setup(x => x.CreateModel())
+                .Returns(channelMock.Object);
+            
+            var connectionFactoryMock = new Mock<IRabbitMqConnectionFactory>();
+            connectionFactoryMock.Setup(x => x.CreateRabbitMqConnection(It.IsAny<RabbitMqClientOptions>()))
+                .Returns(connectionMock.Object);
+
+            var consumer = new AsyncEventingBasicConsumer(channelMock.Object);
+            connectionFactoryMock.Setup(x => x.CreateConsumer(It.IsAny<IModel>()))
+                .Returns(consumer);
+
+            var messageHandlingServiceMock = new Mock<IMessageHandlingService>();
+            var queueService = CreateService(connectionFactoryMock.Object, messageHandlingServiceMock.Object);
+            
+            await consumer.HandleBasicDeliver(
+                "1",
+                0,
+                false,
+                "exchange",
+                "routing,key",
+                null,
+                new ReadOnlyMemory<byte>());
+            messageHandlingServiceMock.Verify(x => x.HandleMessageReceivingEvent(It.IsAny<BasicDeliverEventArgs>(), It.IsAny<IQueueService>()), Times.Never);
+
+            queueService.StartConsuming();
+            
+            for (var i = 1; i <= numberOfMessages; i++)
+            {
+                await consumer.HandleBasicDeliver(
+                    "1",
+                    (ulong)numberOfMessages,
+                    false,
+                    "exchange",
+                    "routing,key",
+                    null,
+                    new ReadOnlyMemory<byte>());
+            }
+
+            messageHandlingServiceMock.Verify(x => x.HandleMessageReceivingEvent(It.IsAny<BasicDeliverEventArgs>(), It.IsAny<IQueueService>()), Times.Exactly(numberOfMessages));
+        }
+
+        IConsumingService CreateService(
+            IRabbitMqConnectionFactory connectionFactory,
+            IMessageHandlingService messageHandlingService)
+        {
+            var guid = Guid.NewGuid();
+            var connectionOptionContainer = new RabbitMqConnectionOptionsContainer
+            {
+                Guid = guid,
+                Options = new RabbitMqConnectionOptions
+                {
+                    ConsumerOptions = new RabbitMqClientOptions()
+                }
+            };
+            var loggerMock = new Mock<ILogger<QueueService>>();
+            return new QueueService(
+                guid,
+                connectionFactory,
+                new List<RabbitMqConnectionOptionsContainer> { connectionOptionContainer },
+                messageHandlingService,
+                new List<RabbitMqExchange>(),
+                loggerMock.Object);
+        }
+    }
+}