fix(EventHubs): Support default consumer group name

src/Testcontainers.EventHubs/EventHubsServiceConfiguration.cs

@@ -58,13 +58,16 @@ private EventHubsServiceConfiguration(NamespaceConfig namespaceConfig)
 
     public static EventHubsServiceConfiguration Create()
     {
-        var namespaceConfig = new NamespaceConfig("EventHub", "ns-1", Array.Empty<Entity>());
+        var namespaceConfig = new NamespaceConfig("EventHub", "emulatorns1", Array.Empty<Entity>());
         return new EventHubsServiceConfiguration(namespaceConfig);
     }
 
     public EventHubsServiceConfiguration WithEntity(string name, int partitionCount, params string[] consumerGroupNames)
     {
-        return WithEntity(name, partitionCount, new ReadOnlyCollection<string>(consumerGroupNames));
+        // Filter out the consumer group name `$default` because the `$default` group
+        // is created automatically by the container image.
+        var validConsumerGroupNames = consumerGroupNames.Where(consumerGroupName => !"$default".Equals(consumerGroupName, StringComparison.OrdinalIgnoreCase)).ToList();
+        return WithEntity(name, partitionCount, new ReadOnlyCollection<string>(validConsumerGroupNames));
     }
 
     public EventHubsServiceConfiguration WithEntity(string name, int partitionCount, IEnumerable<string> consumerGroupNames)
@@ -77,8 +80,10 @@ public EventHubsServiceConfiguration WithEntity(string name, int partitionCount,
 
     public bool Validate()
     {
-        Predicate<Entity> isValidEntity = entity => entity.PartitionCount > 0 && entity.PartitionCount <= 32 && entity.ConsumerGroups.Count > 0 && entity.ConsumerGroups.Count <= 20;
-        return _namespaceConfig.Entities.All(entity => isValidEntity(entity));
+        // The emulator provides the usage quotas as described at:
+        // https://learn.microsoft.com/en-us/azure/event-hubs/overview-emulator#usage-quotas.
+        Predicate<Entity> isValidEntity = entity => entity.PartitionCount > 0 && entity.PartitionCount <= 32 && entity.ConsumerGroups.Count >= 0 && entity.ConsumerGroups.Count <= 20;
+        return _namespaceConfig.Entities.Count > 0 && _namespaceConfig.Entities.Count <= 10 && _namespaceConfig.Entities.All(entity => isValidEntity(entity));
     }
 
     public string Build()

tests/Testcontainers.EventHubs.Tests/EventHubsContainerTest.cs

@@ -26,7 +26,7 @@ public Task DisposeAsync()
 
     private static EventHubsServiceConfiguration GetServiceConfiguration()
     {
-        return EventHubsServiceConfiguration.Create().WithEntity(EventHubsName, 2, EventHubsConsumerGroupName);
+        return EventHubsServiceConfiguration.Create().WithEntity(EventHubsName, 2, [EventHubConsumerClient.DefaultConsumerGroupName, EventHubsConsumerGroupName]);
     }
 
     [Fact]
@@ -36,22 +36,27 @@ public async Task SendEventDataBatchShouldNotThrowException()
         // Given
         var message = Guid.NewGuid().ToString();
 
-        await using var client = new EventHubProducerClient(_eventHubsContainer.GetConnectionString(), EventHubsName);
+        var readOptions = new ReadEventOptions();
+        readOptions.MaximumWaitTime = TimeSpan.FromSeconds(5);
 
-        // When
-        var properties = await client.GetEventHubPropertiesAsync()
-            .ConfigureAwait(true);
+        await using var producer = new EventHubProducerClient(_eventHubsContainer.GetConnectionString(), EventHubsName);
+
+        await using var consumer = new EventHubConsumerClient(EventHubsConsumerGroupName, _eventHubsContainer.GetConnectionString(), EventHubsName);
 
-        using var eventDataBatch = await client.CreateBatchAsync()
+        // When
+        using var eventDataBatch = await producer.CreateBatchAsync()
             .ConfigureAwait(true);
 
-        eventDataBatch.TryAdd(new EventData(message));
+        _ = eventDataBatch.TryAdd(new EventData(message));
 
-        await client.SendAsync(eventDataBatch)
+        await producer.SendAsync(eventDataBatch)
             .ConfigureAwait(true);
 
+        var asyncEnumerator = consumer.ReadEventsAsync(readOptions).GetAsyncEnumerator();
+        _ = await asyncEnumerator.MoveNextAsync();
+
         // Then
-        Assert.NotNull(properties);
+        Assert.Equal(message, Encoding.UTF8.GetString(asyncEnumerator.Current.Data.Body.Span));
     }
     // # --8<-- [end:UseEventHubsContainer]
 

tests/Testcontainers.EventHubs.Tests/Usings.cs

@@ -1,6 +1,8 @@
 global using System;
+global using System.Text;
 global using System.Threading.Tasks;
 global using Azure.Messaging.EventHubs;
+global using Azure.Messaging.EventHubs.Consumer;
 global using Azure.Messaging.EventHubs.Producer;
 global using DotNet.Testcontainers.Builders;
 global using DotNet.Testcontainers.Commons;