c# - AppSettings.json for Integration Test in ASP.NET Core

Question

I am following this guide. I have a Startup in the API project that uses an appsettings.json configuration file.

public class Startup
{
    public Startup(IHostingEnvironment env)
    {
        var builder = new ConfigurationBuilder()
            .SetBasePath(env.ContentRootPath)
            .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true)                
            .AddEnvironmentVariables();
        Configuration = builder.Build();

        Log.Logger = new LoggerConfiguration()
            .Enrich.FromLogContext()
            .ReadFrom.Configuration(Configuration)
            .CreateLogger();
    }

The particular part I'm looking at is the env.ContentRootPath. I did some digging around and it looks like my appsettings.json isn't actually copied to the bin folder but that is fine as ContentRootPath is returning MySolutionsrcMyProject.Api, which is where the appsettings.json file is located.

So in my integration test project I have this test:

public class TestShould
{
    private readonly TestServer _server;
    private readonly HttpClient _client;

    public TestShould()
    {
        _server = new TestServer(new WebHostBuilder().UseStartup<Startup>());
        _client = _server.CreateClient();
    }

    [Fact]
    public async Task ReturnSuccessful()
    {
        var response = await _client.GetAsync("/monitoring/test");
        response.EnsureSuccessStatusCode();

        var responseString = await response.Content.ReadAsStringAsync();

        Assert.Equal("Successful", responseString);
    }

This is basically copy and paste from the guide. When I debug this test, ContentRootPath is actually MySolutionsrcMyProject.IntegrationTestsinDebug et461, which is obviously the build output folder for the test project and again the appsettings.json file is not there (yes I do have another appsettings.json file in the test project itself) so the test fails at creating the TestServer.

I tried getting around this by modifying the test project.json file.

"buildOptions": {
    "emitEntryPoint": true,
    "copyToOutput": {
        "includeFiles": [
            "appsettings.json"
       ]
    }
}

I hoped this would copy the appsettings.json file to the build output directory but it complains about the project missing a Main method for an entry point, treating the test project like a console project.

What can I do to get around this? Am I doing something wrong?

Answer 1

Integration test on ASP.NET.Core 2.0 follow MS guide ,

You should right click appsettings.json set its property Copy to Output directory to Copy always

And now you could find the json file in output folder, and build TestServer with

var projectDir = GetProjectPath("", typeof(TStartup).GetTypeInfo().Assembly);
_server = new TestServer(new WebHostBuilder()
    .UseEnvironment("Development")
    .UseContentRoot(projectDir)
    .UseConfiguration(new ConfigurationBuilder()
        .SetBasePath(projectDir)
        .AddJsonFile("appsettings.json")
        .Build()
    )
    .UseStartup<TestStartup>());



/// Ref: https://stackoverflow.com/a/52136848/3634867
/// <summary>
/// Gets the full path to the target project that we wish to test
/// </summary>
/// <param name="projectRelativePath">
/// The parent directory of the target project.
/// e.g. src, samples, test, or test/Websites
/// </param>
/// <param name="startupAssembly">The target project's assembly.</param>
/// <returns>The full path to the target project.</returns>
private static string GetProjectPath(string projectRelativePath, Assembly startupAssembly)
{
    // Get name of the target project which we want to test
    var projectName = startupAssembly.GetName().Name;

    // Get currently executing test project path
    var applicationBasePath = System.AppContext.BaseDirectory;

    // Find the path to the target project
    var directoryInfo = new DirectoryInfo(applicationBasePath);
    do
    {
        directoryInfo = directoryInfo.Parent;

        var projectDirectoryInfo = new DirectoryInfo(Path.Combine(directoryInfo.FullName, projectRelativePath));
        if (projectDirectoryInfo.Exists)
        {
            var projectFileInfo = new FileInfo(Path.Combine(projectDirectoryInfo.FullName, projectName, $"{projectName}.csproj"));
            if (projectFileInfo.Exists)
            {
                return Path.Combine(projectDirectoryInfo.FullName, projectName);
            }
        }
    }
    while (directoryInfo.Parent != null);

    throw new Exception($"Project root could not be located using the application root {applicationBasePath}.");
}

Ref: TestServer w/ WebHostBuilder doesn't read appsettings.json on ASP.NET Core 2.0, but it worked on 1.1