Event Hubs

The Arcus.Testing.Messaging.EventHubs package provides test fixtures related to Azure Event Hubs. It adheres to the 'clean environment' testing practice by providing a temporary Event Hub.

Installation

The following functionality is available when installing this package:

PM> Install-Package -Name Arcus.Testing.Messaging.EventHubs

Temporary hub

The TemporaryEventHub provides a solution when the integration test requires an Azure Event Hub during the test run. The test fixture creates a hub upon the setup of the fixture and deletes it again when the fixture disposes.

✨ When the test fixture was responsible for creating the hub, the fixture will delete the hub when the test disposes the fixture. This follows the 'clean environment' testing principle that describes that a test should revert the environment to its original state after the test has run.

using Arcus.Testing;

ResourceIdentifier eventHubsNamespaceResourceId =
    EventHubsNamespaceResource.CreateResourceIdentifier("<subscription-id", "<resource-group>", "<namespace-name>");

await using var hub = await TemporaryEventHub.CreateIfNotExistsAsync(
    eventHubsNamespaceResourceId, consumerGroup: "$Default", "<event-hub-name>", logger);

⚡ Uses by default the DefaultAzureCredential but supports other authentication mechanisms with overloads that take in the EventHubsNamespaceResource directly:

 var credential = new DefaultAzureCredential();
 var arm = new ArmClient(credential);
 
 EventHubsNamespaceResource eventHubsNamespace =
     await arm.GetEventHubsNamespaceResource(eventHubNamespaceResourceId)
              .GetAsync();

Customization

The TemporaryEventHub allows testers to configure setup operations to manipulate the test fixture's behavior.

using Arcus.Testing;

await TemporaryEventHub.CreateIfNotExistsAsync(..., options =>
{
    // Options related to when the test fixture is set up.
    // ---------------------------------------------------

    // Change the default hub-creation behavior.
    options.OnSetup.CreateHubWith((EventHubData hub) =>
    {
        hub.PartitionCount = 4;
    });
});

Search for events

The TemporaryEventHub has an event filtering system that allows testers to search for events during the lifetime of the test fixture. This can be useful to verify the current state of a hub, or as a test assertion to verify EventHubs-related implementations.

using Arcus.Testing;

await using TemporaryEventHub hub = ...

IEnumerable<PartitionEvent> events =
    await hub.Events

              // Get subset events currently on the hub.
             .Where(ev => ev.Data.Properties.ContainsKey("<my-key"))
             .Where(ev => ev.Data.ContentType == "application/json")

              // Get events only from a single partition.
             .FromPartition("<partition-id>", EventPosition.Earliest)

              // Configures the read options that will be associated with the search operation.
             .ReadWith((ReadEventOptions opt) =>
             {
                 opt.MaximumWaitTime = TimeSpan.FromSeconds(10);
                 opt.OwnerLevel = 10;
             })

             // Start searching for events.
             .ToListAsync();