TestServer.Configuration.InMemorySettings 2.0.0

TestServer.Configuration.InMemorySettings

Background

To streamline configuration in my Microsoft.NET.Sdk.Web projects I usually create POCO like objects like this:

public class Settings 
{
    public string ApplicationName { get; set; }
    public SwaggerSettings SwaggerSettings { get; set; } = new();
    
    //.. snip for brevity ..
    
    public static Settings From(IConfiguration configuration)
    {
        var settings = new Settings();
        configuration.Bind(settings);

        return settings;
    }
}

public class Startup
{
    private readonly Settings _settings;
    public Startup(IConfiguration configuration)
    {
        _settings = Settings.From(configuration);
        //.. snip for brevity ..
    }
}

I also really love Microsoft.AspNetCore.TestHost. While using this tool I have run into the whole configuration of settings yack shaving a couple of times. To address this problem Microsoft have created MemoryConfigurationBuilderExtensions in Microsoft.Extensions.Configuration which adds the following extension method:

public static IConfigurationBuilder AddInMemoryCollection(this IConfigurationBuilder configurationBuilder, IEnumerable<KeyValuePair<string, string>> initialData);

This is a pretty clean solution, would it not be that I now have to create a IEnumerable<KeyValuePair<string, string>> and keep that in sink.

This is my solution to that problem. As I already have a Settings object I just want to convert this to the required IEnumerable<KeyValuePair<string, string>>

Usage

var settings = new Settings 
                   {
                        ApplicationName = "ApplicationName"
                        //.. snip for brevity ..
                   };
TestServer testServer = new WebHostBuilder().UseEnvironment("Test")
                                            .UseStartup<Startup>()
                                            .ConfigureAppConfiguration(builder => 
                                            {
                                                builder.AddSettings(settings)
                                            });

Disclamer

The reflection I'm using to accomplish this conversion is quite naive and past experience has tought me that there are bugs in this code. If you find a scenario that doesn't work for you please submit a issue.