Implement the decorator pattern

Signed-off-by: Fabio José <fabiojose@gmail.com>

lib/formats/json/parser.js

@@ -4,8 +4,8 @@ const {
   isStringOrObjectOrThrow
 } = require("../../utils/fun.js");
 
-function JSONParser() {
-
+function JSONParser(decorator) {
+  this.decorator = decorator;
 }
 
 const invalidPayloadTypeError =
@@ -44,9 +44,14 @@ function validateSpec(payload, spec) {
 }
 
 JSONParser.prototype.parse = function(payload) {
+  let toparse = payload;
+
+  if(this.decorator) {
+    toparse = this.decorator.parse(payload);
+  }
 
   //is that string? is that JSON?
-  var valid = validateAndParse(payload);
+  var valid = validateAndParse(toparse);
 
   return valid;
 };