configureappio

using System;
public class C {
    public void M(string value)
    {                
        if (value is null!) throw new ArgumentNullException(nameof(value));       
        
        // works in NET 5 (C#9) but fails in 6 RC1 (C#10) with error CS8598: The suppression operator is not allowed in this context        
        
        // I can see why as the null does not need a null foriving as string is not a declared string?
        // so it is correct to flag as a code smell, but should the error CS8598 be an error or a warning when migrating NET5 code?

configureappio

private interface IKelvinMapper
{
    decimal ToKelvins(decimal value);
}

private class CentigradeToKelvinMapper : IKelvinMapper
{
    public decimal ToKelvins(decimal value) => value + 273.15M;
}

configureappio

public class Startup
{
    public Startup(IConfiguration configuration)
    {
        Configuration = configuration;
    }

    public IConfiguration Configuration { get; }

    public void ConfigureServices(IServiceCollection services)

configureappio

public interface IAppSettings
{
    string ApplicationName { get;  }        
}

public interface ISqlConnectionSettings 
{        
    string SqlConnectionSting { get; }
}

configureappio

    public class MyAppSettingsBridge : IAppSettingsResolved
    {
        private readonly IOptions<MyAppSettings> _appSettings;

        private readonly ISettingsDecrypt _decryptor;

        public MyAppSettingsBridge(IOptionsSnapshot<MyAppSettings> appSettings, ISettingsDecrypt decryptor, ISettingsValidator validator) {
            _appSettings = appSettings ?? throw new ArgumentNullException(nameof(appSettings));
            _decryptor = decryptor ?? throw new ArgumentException(nameof(decryptor));
            if (validator == null) throw new ArgumentNullException(nameof(validator));

configureappio

    public class SettingsValidator : ISettingsValidator
    {
        public bool TryValidate(IAppSettingsStructure settings, out AggregateException validationExceptions)
        {
            if (settings == null) throw new ArgumentNullException(nameof(settings));
            
            var exceptions = new List<Exception>();

            if (settings.ApplicationName == null) exceptions.Add(new ArgumentNullException(nameof(settings.ApplicationName)));
            if (string.IsNullOrWhiteSpace(settings.ApplicationName)) exceptions.Add(new ArgumentOutOfRangeException(nameof(settings.ApplicationName)));

configureappio

    public class SettingsDecryptor : ISettingsDecrypt
    {
        private readonly ICryptoAlgorithm _crypto;
        public SettingsDecryptor(ICryptoAlgorithm crypto)
        {
            _crypto = crypto ?? throw new ArgumentNullException(nameof(crypto));
        }

        public string Decrypt(string key, IDictionary<string, string> keyValues)
        {

configureappio

    public interface ICryptoFactory
    {
        ICryptoAlgorithm Create<T>(string password, string salt) where T : SymmetricAlgorithm, new();
        ICryptoAlgorithm Create(Type type, string password, string salt);
    }

    public interface ICryptoAlgorithm
    {
        string Decrypt(string text);
        string Encrypt(string text);

configureappio

    public class MyAppSettings : IAppSettingsStructure
    {
        public string ApplicationName { get; set; }
        public Dictionary<string, string> Secrets { get; set; } = new Dictionary<string, string>();
    } 

configureappio

{
  "Logging": {
    "IncludeScopes": false,
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "MyAppSettings": {
    "ApplicationName": "My Cool Application",
    "Secrets": {