AzureFunctions.TestFramework.EventHubs 0.11.2

AzureFunctions.TestFramework.EventHubs

EventHubTrigger invocation support for the Azure Functions Test Framework. Provides InvokeEventHubAsync(...) and InvokeEventHubBatchAsync(...) — extensions on IFunctionsTestHost that let you trigger Event Hubs-triggered functions directly from integration tests without a real Azure Event Hubs namespace.

Usage

using Azure.Messaging.EventHubs;
using AzureFunctions.TestFramework.Core;
using AzureFunctions.TestFramework.EventHubs;

public class EventHubFunctionTests : IAsyncLifetime
{
    private IFunctionsTestHost _testHost;

    public async Task InitializeAsync()
    {
        _testHost = await new FunctionsTestHostBuilder()
            .WithFunctionsAssembly(typeof(MyEventHubFunction).Assembly)
            .BuildAndStartAsync();
    }

    // Single event (IsBatched = false)
    [Fact]
    public async Task ProcessEvent_WithSingleEventData_Succeeds()
    {
        var eventData = new EventData(BinaryData.FromString("Hello from Event Hubs!"));

        var result = await _testHost.InvokeEventHubAsync("ProcessEventHubMessage", eventData);
        Assert.True(result.Success);
    }

    // Batch events (default IsBatched = true)
    [Fact]
    public async Task ProcessEvents_WithBatch_Succeeds()
    {
        var events = new[]
        {
            new EventData(BinaryData.FromString("Event 1")),
            new EventData(BinaryData.FromString("Event 2")),
        };

        var result = await _testHost.InvokeEventHubBatchAsync("ProcessEventHubBatch", events);
        Assert.True(result.Success);
    }

    // Output binding capture
    [Fact]
    public async Task ProcessEvent_WithOutputBinding_CapturesOutput()
    {
        var eventData = new EventData(BinaryData.FromString("trigger"));

        var result = await _testHost.InvokeEventHubAsync("ProcessAndForward", eventData);

        Assert.True(result.Success);
        var output = result.ReadReturnValueAs<string>();
        Assert.NotNull(output);
    }

    public async Task DisposeAsync() => await _testHost.DisposeAsync();
}

API

// Single event (use when IsBatched = false)
Task<FunctionInvocationResult> InvokeEventHubAsync(
    this IFunctionsTestHost host,
    string functionName,
    EventData eventData,
    CancellationToken cancellationToken = default)

// Batch events (use when IsBatched = true, the default)
Task<FunctionInvocationResult> InvokeEventHubBatchAsync(
    this IFunctionsTestHost host,
    string functionName,
    IReadOnlyList<EventData> events,
    CancellationToken cancellationToken = default)

• functionName — the name of the Event Hubs function (case-insensitive).
• eventData — the single EventData to pass to the function.
• events — the batch of EventData instances to pass to the function.

Output Bindings

[EventHubOutput] output bindings are captured generically by FunctionInvocationResult.OutputData — no extra configuration is needed:

var result = await _testHost.InvokeEventHubAsync("MyFunction", eventData);
var output = result.ReadOutputAs<string>("outputEventHub");  // named output binding
// OR for return value output:
var output = result.ReadReturnValueAs<string>();

Notes

• Batch mode is the default for [EventHubTrigger] (IsBatched = true). Use InvokeEventHubBatchAsync for batch-mode functions and InvokeEventHubAsync for single-event functions (IsBatched = false).
• Both single and batch overloads encode EventData as AMQP messages using the same wire format as the Azure Functions Event Hubs extension.
• EventData properties such as MessageId, CorrelationId, and custom properties set via Properties are preserved through AMQP encoding.

References

• Azure Functions Event Hubs trigger
• Azure Functions Event Hubs output
• Azure.Messaging.EventHubs

License

MIT