Microsoft.Extensions.Configuration has a very poor debugging experience.

Configuration code:

var configuration = new ConfigurationBuilder()
    .AddJsonFile("appsettings.json")
    .Build();

Configuration file:

{
  "Logging": {
    "LogLevel": {
      "Default": "Information",
      "Microsoft.AspNetCore": "Warning"
    }
  },
  "AllowedHosts": "*"
}

Multiple levels of searching are required before a view of the configuration is available:

Also, if there are multiple providers, this is no a way to view the merged, final results.

DebuggerDisplay and DebuggerTypeProxy should be added to implementations of IConfiguration and friends to make it simple to get an easy-to-use view of what debug values there are.

The values in the Data collection are already pretty good. We just need to display the merged, final results as a view with a type proxy and the counter with debugger display.