I want to perform integration testing on an Azure Function app (.NET 9 / isolated worker), similar to how it's normally performed using Microsoft.AspNetCore.Mvc.Testing on ASP.NET Core apps:

.AspNetCore.Mvc.Testing

The Function app is created using an FunctionsApplicationBuilder:

var builder = FunctionsApplication.CreateBuilder(args);
...
var host = builder.Build()
await host.Run()

For ASP.NET Core apps, I would normally use the testing package above to create an in-memory instance of my web application, with mocked out services, e.g. database, and then call the endpoints using HttpClient.PostAsJsonAsync.

In case of Function apps, this package doesn't apply, so how would I perform similar testing?