Create XUnit test for configureappconfiguration

Question

I would like to create a test for configureappconfiguration using XUnit. I used .ConfigureWebJobs(startup.Configure) whic just calls the Confure method in my Startup.cs. I want to call configureappconfiguration so it will test that also. But having a hard time finding how to do that.

Answer 1

.ConfigureWebJobs has an overload which accepts delegate of configureAppConfiguration

public static IHostBuilder ConfigureWebJobs(this IHostBuilder builder, Action<HostBuilderContext, IWebJobsBuilder> configure, Action<JobHostOptions> configureOptions, Action<HostBuilderContext, IWebJobsConfigurationBuilder> configureAppConfiguration)

Using that as below in test, I could run startup test successfully which calls ConfigureAppConfiguration. Below is just a simple example. You can configure as per your need. Setting up the proper parameters is bit tricky to match Function interfaces.

My startup.cs:

[assembly: Microsoft.Azure.Functions.Extensions.DependencyInjection.FunctionsStartup(typeof(FunctionApp1.Startup))]
namespace FunctionApp1
{
    using Microsoft.Azure.Functions.Extensions.DependencyInjection;
    using Microsoft.Extensions.DependencyInjection;

    public class Startup : FunctionsStartup
    {
        public override void Configure(IFunctionsHostBuilder builder)
        {
            builder.Services.AddSingleton(typeof(IMyInterface<,>), typeof(MyClass<>));
        }

        public override void ConfigureAppConfiguration(IFunctionsConfigurationBuilder builder)
        {
            base.ConfigureAppConfiguration(builder);
        }
    }
}

My startup test:

namespace XUnitTestProject1
{
    using FunctionApp1;

    using Microsoft.Azure.Functions.Extensions.DependencyInjection;
    using Microsoft.Extensions.Hosting;

    using Moq;

    using Xunit;

    public class UnitTest1
    {
        [Fact]
        public void StartupTest()
        {
            var functionConfigurationBuilderMock = new Mock<IFunctionsConfigurationBuilder>();
            var startup = new Startup();
            var host = new HostBuilder()
                .ConfigureWebJobs((c, b) => startup.Configure(b), 
                                   null,
                                   (c, b) => {
                                       functionConfigurationBuilderMock.SetupGet(m => m.ConfigurationBuilder).Returns(b.ConfigurationBuilder);
                                       startup.ConfigureAppConfiguration(functionConfigurationBuilderMock.Object);
                                   })
                .Build();

             // Assert blah blah
        }
    }
}

Answer 2

Hello @Brett McDonald , thanks for reaching out to us, your question is appreciated.

You can use Microsoft.AspNetCore.Mvc.Testing package to achieve this scenario. I have done a quick setup to show you how to do this.

As I understand, you want to call GenericWebHostBuilder.ConfigureAppConfiguration method in your Unit Tests using XUnit. To do this please follow below steps:

• Run the below command to add Microsoft.AspNetCore.Mvc.Testing package in your Test project:

     dotnet add  package Microsoft.AspNetCore.Mvc.Testing  
  

  The packages includes a WebApplicationFactory<TEntryPoint> class which is used to bootstrap the API in memory. This is convenient, as we don't need to have the API running before we run these tests.
• Inject WebApplicationFactory<Api.Startup> in your constructor like below:
• Run the test. This will call CreateHostBuilder in your Program.cs, and thus, ConfigureAppConfiguration method will be called. Please see the call stack of this below:

*If you want to create custom WebApplicationfactory, you can check out this article as it has detailed and step-by-step process to do that. *

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