json chisel command

json.py

#!/usr/bin/python
# Example file with custom commands, located at /magical/commands/example.py

import lldb
import fbchisellldbbase as fb

def lldbcommands():
  return [ JSON() ]
  
class JSON(fb.FBCommand):
  def name(self):
    return 'json'
    
  def description(self):
    return 'Print the json from a data object.'
    
  def args(self):
    return [
      fb.FBCommandArgument(
        arg="data",
        type="Data",
        help="Data that will be evaluated when deserializing.",
      )
    ]

  def run(self, arguments, options):
    # It's a good habit to explicitly cast the type of all return
    # values and arguments. LLDB can't always find them on its own.
    objectToPrint = fb.evaluateInputExpression("{obj} as NSObject".format(obj=arguments[0]))

    jsonData = fb.evaluateExpressionValue("(NSString*)[[NSString alloc] initWithData:(NSObject*){} encoding:4]".format(objectToPrint)).GetObjectDescription()
    print(jsonData)