AzureFunctions.TestFramework.DataExplorer 0.14.0-preview

AzureFunctions.TestFramework.DataExplorer

Azure Data Explorer (Kusto) Input and Output binding support for the Azure Functions Test Framework.

Installation

dotnet add package AzureFunctions.TestFramework.DataExplorer

Supported bindings

ℹ️ Azure Data Explorer has no trigger binding in the isolated worker extension. Use another trigger type (for example Queue, Timer, or HTTP) and assert Kusto input/output behavior in that invocation.

Kusto Input Binding

Register fake rows via the builder so they are injected automatically for every invocation:

var host = await new FunctionsTestHostBuilder()
    .WithFunctionsAssembly(typeof(MyFunction).Assembly)
    .WithHostBuilderFactory(Program.CreateHostBuilder)
    // Inject rows for [KustoInput("MyDb", KqlCommand = "InputTable | take 10")]
    .WithKustoInputRows(
        database: "MyDb",
        table: "InputTable",
        rows:
        [
            new Product { Id = 1, Name = "Widget" },
            new Product { Id = 2, Name = "Gadget" }
        ])
    .BuildAndStartAsync();

Use WithKustoInputRows<T>(database, table, T row) to inject a single row, WithKustoInputRows<T>(database, table, IReadOnlyList<T> rows) to inject multiple rows, and WithKustoInputJson(database, table, json) to inject raw JSON.

Function example

[Function("ReadKustoProducts")]
public void Run(
    [QueueTrigger("kusto-input-queue")] string queueMessage,
    [KustoInput("MyDb", KqlCommand = "InputTable | take 10")] IReadOnlyList<Product> products)
{
    foreach (var product in products)
        _logger.LogInformation("Product: {Name}", product.Name);
}

Kusto Output Binding

Output bindings are captured automatically via FunctionInvocationResult:

var result = await host.InvokeQueueAsync("WriteKustoOutput", "source");

Assert.True(result.Success);
var written = result.ReadReturnValueAs<Product>();
Assert.Equal("copy:source", written?.Name);

Function example

[Function("WriteKustoOutput")]
[KustoOutput("MyDb", TableName = "OutputTable")]
public Product Run([QueueTrigger("kusto-output-queue")] string message)
{
    return new Product { Id = 1, Name = $"copy:{message}" };
}

Known limitation

WithKustoInputRows(database, table, ...) matches by database and the first table identifier in KqlCommand (for example "InputTable | take 10"). If your query starts with declare statements or does not begin with a table identifier, use WithKustoInputJson(...) with a matching database/table registration strategy in your tests.

Testing across all four flavours

Add the Data Explorer package reference to your test project and all four function-app test flavours:

<PackageReference Include="AzureFunctions.TestFramework.DataExplorer" />

See the 4-flavour matrix test pattern for the concrete test class structure.