AzureFunctions.TestFramework.Blob 0.11.2

AzureFunctions.TestFramework.Blob

BlobTrigger and BlobInput support for the Azure Functions Test Framework. Provides:

• InvokeBlobAsync(...) — trigger blob-triggered functions directly from tests.
• WithBlobInputContent(...) — inject fake blob content for functions that use [BlobInput] (non-trigger input binding).

BlobTrigger invocation

using AzureFunctions.TestFramework.Blob;
using AzureFunctions.TestFramework.Core;

public class BlobFunctionTests : IAsyncLifetime
{
    private IFunctionsTestHost _testHost;

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

    [Fact]
    public async Task ProcessBlob_WithTextContent_Succeeds()
    {
        var content = BinaryData.FromString("Hello from blob!");
        var result = await _testHost.InvokeBlobAsync("ProcessBlob", content, blobName: "test/file.txt");
        Assert.True(result.Success);
    }

    [Fact]
    public async Task ProcessBlob_WithJsonContent_Succeeds()
    {
        var content = BinaryData.FromObjectAsJson(new { id = "123", name = "test" });
        var result = await _testHost.InvokeBlobAsync(
            "ProcessBlob", content,
            blobName: "orders/order-123.json",
            containerName: "orders");
        Assert.True(result.Success);
    }

    public async Task DisposeAsync()
    {
        await _testHost.StopAsync();
        _testHost.Dispose();
    }
}

[BlobInput] injection

The WithBlobInputContent builder extension injects fake blob content for functions that use the [BlobInput] attribute (non-trigger input binding).

// Function under test
[Function("ReadDocument")]
public static string Run(
    [QueueTrigger("process-queue")] string blobPath,
    [BlobInput("documents/template.txt")] string templateContent)
{
    return $"Template: {templateContent}";
}

// Test setup
using AzureFunctions.TestFramework.Blob;

_testHost = await new FunctionsTestHostBuilder()
    .WithFunctionsAssembly(typeof(MyFunction).Assembly)
    // Register the content to inject for [BlobInput("documents/template.txt")]
    .WithBlobInputContent("documents/template.txt", BinaryData.FromString("Hello, template!"))
    .BuildAndStartAsync();

Multiple blobs: Use the dictionary overload to register several paths at once:

_testHost = await new FunctionsTestHostBuilder()
    .WithFunctionsAssembly(typeof(MyFunction).Assembly)
    .WithBlobInputContent(new Dictionary<string, BinaryData>
    {
        ["documents/template.txt"] = BinaryData.FromString("Hello, template!"),
        ["configs/settings.json"] = BinaryData.FromObjectAsJson(new { timeout = 30 }),
    })
    .BuildAndStartAsync();

The blobPath key must match the path declared in the [BlobInput] attribute exactly (case-insensitive). Dynamic path templates (e.g. "documents/{queueTrigger}") are matched against the template string, not the resolved path. When no content is registered for a binding, an empty byte[] is injected (which the worker surfaces as null / empty for string and stream parameters).

Supported parameter types: string, byte[], Stream, BinaryData, ReadOnlyMemory<byte>. Complex types like BlobClient/BlockBlobClient use a different binding mechanism (model binding data) and are not supported by WithBlobInputContent. For those types, override the blob SDK client via ConfigureServices.

References

• Full documentation
• AzureFunctions.TestFramework.Core

License

MIT