Please add an example of got to validate nested JSON body elements

[codeonion]

So lets see this JSON body

{
	"configuration": {
		"type": "",
		"height": "apple",
		"width": false,
		"cost_in_usd": "not afforable"
	}
}

If this is posted in a POST request, and I am using

require 'rack' require 'rack/contrib'

and

use Rack::JSONBodyParser
helpers Sinatra::Param

I need to know how to validate the above mentioned JSON keys under configuration.

Type is empty, height and width and cost have wrongly provided values.