AppProfiling.json

{
  "EnableProfiling": "false",
  "IsProfilerWhitelisting": "true",
  "ProfilerProvider": "ADOT.Core.Profiling.SingletonProfilerProvider",
  "IncludedTypes": [
    "ADOT.Core.Profiling.StopwatchFactory",
    "ADOT.Core.Profiling.SingletoneProfilerProvider"
  ],
  "IncludedNamespaces": [
    "ADOT.DataAccess",
    "ADOT.Logging"
  ]
}

ProfilerFactoryConverter.cs

public class ProfilerFactoryConverter : CustomCreationConverter<IAppProfilerFactory>
{
    public override IAppProfilerFactory Create(Type objectType)
    {
        // We don't use this - ReadJson below is used instead.
        // Inheriting from CustomCreationConverter requires that we expose this method though.
        throw new NotSupportedException();       
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        JToken jsonObject = JObject.ReadFrom(reader);
        string providerTypeToActivate = jsonObject.Value<string>();
        Type typeToActivate = Type.GetType(providerTypeToActivate);
        object instancedObject = Activator.CreateInstance(typeToActivate);

        return instancedObject as IAppProfilerFactory;
    }
}

Settings.cs

    public partial class ProfileRuntimeSettings
    {
        public static ProfileRuntimeSettings Load()
        {
            string json = File.ReadAllText("AppProfiling.json");
            var settings = JsonConvert.DeserializeObject<ProfileRuntimeSettings>(json);

            return settings;
        }

        [JsonConverter(typeof(ProfilerFactoryConverter))]
        public IAppProfilerFactory ProfilerProvider { get; set; }

        public bool EnableProfiling { get; set; }
        
        public bool IsProfilerWhitelisting { get; set; } = true;
        
        public string[] IncludedTypes { get; set; }
        
        public string[] IncludedNamespaces { get; set; }
    }

UnitTest.cs

[TestMethod]
public void ProfilerSettings_IsLoadedFromJson()
{
    // Arrange
    AppProfiler.LoadSettings();

    // Act
    IAppProfiler profiler = AppProfiler.GlobalSettings.ProfilerProvider.Create();

    // Act
    Assert.IsNotNull(profiler);
}