Functional Testing of ASP.NET core 2.1 MVC Application

In ASP.NET core 2.1, setting up functional testing project got much easier with the release of Microsoft.AspNetCore.Mvc.Testing nuget package. In this post we are going to setup a functional test project.

Prerequisite

To follow this tutorial you should have-

1. .NET Core 2.1 RC1 SDK and
2. VS Code or Microsoft Visual Studio 2017 v15.7 Preview 1 or newer, installed on your system

Create test project

Create a folder and name it HelloWorld, because why not . Open PowerShell window inside the folder (Shift + right click anywhere inside the folder and select Open PowerShell window here) and create a solution:

dotnet new sln

Now create a basic MVC project inside src directory and xunit project inside tests directory:

dotnet new mvc -o .\src\HelloWorld.Mvc
dotnet new xunit -o .\tests\HelloWorld.FunctionalTests

Add those two project to the solution:

dotnet sln add .\src\HelloWorld.Mvc\HelloWorld.Mvc.csproj
dotnet sln add .\tests\HelloWorld.FunctionalTests\HelloWorld.FunctionalTests.csproj

Reference the MVC project form the FunctionalTests project:

dotnet add .\tests\HelloWorld.FunctionalTests\HelloWorld.FunctionalTests.csproj reference .\src\HelloWorld.Mvc\HelloWorld.Mvc.csproj

Write functional Test

Add Microsoft.AspNetCore.Mvc.Testing to the functional test project:

dotnet add .\tests\HelloWorld.FunctionalTests\HelloWorld.FunctionalTests.csproj package Microsoft.AspNetCore.Mvc.Testing -v 2.1.0-rc1-final

Now open the project in VS Code or Visual Studio 2017 15.7 Preview 1 or newer and create a new class inside HelloWorld.FunctionalTests project and name it HomePageShould.cs

using HelloWorld.Mvc;
using Microsoft.AspNetCore.Mvc.Testing;
using System.Net;
using System.Net.Http;
using System.Threading.Tasks;
using Xunit;

namespace HelloWorld.FunctionalTests
{
    public class HomePageShould : IClassFixture<WebApplicationFactory<Startup>>
    {
        private readonly HttpClient _client;

        public HomePageShould(WebApplicationFactory<Startup> factory)
        {
            _client = factory.CreateClient();
        }

        [Fact]
        public async Task ReturnHttpStatusCodeOk()
        {
            var response = await _client.GetAsync("/");

            Assert.Equal(HttpStatusCode.OK, response.StatusCode);
        }
    }
}

Run the test

Now run the test. It should fail with the error message

Message: System.IO.FileNotFoundException : Could not load file or assembly ‘Microsoft.AspNetCore, Version=2.1.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60’. The system cannot find the file specified.

To resolve it, add Microsoft.AspNetCore.App nuget package to the test project

dotnet add .\tests\HelloWorld.FunctionalTests\HelloWorld.FunctionalTests.csproj package Microsoft.AspNetCore.App -v 2.1.0-rc1-final

Now run the test from Test>Run>All Tests (Visual Studio 2017) or from PowerShell-

dotnet test .\tests\HelloWorld.FunctionalTests\HelloWorld.FunctionalTests.csproj

You should see green tick of happiness.