diff --git a/lib/formats/json/parser.js b/lib/formats/json/parser.js
index 02f068e..cb82cc1 100644
--- a/lib/formats/json/parser.js
+++ b/lib/formats/json/parser.js
@@ -1,7 +1,7 @@
 const {
   isString,
-  isObject,
-  isDefined
+  isDefinedOrThrow,
+  isValidOrThrow
 } = require("../../utils/fun.js");
 
 function JSONParser() {
@@ -14,20 +14,7 @@ const invalidPayloadTypeError =
 const nullOrIndefinedPayload =
   new Error("null or undefined payload");
 
-// Functions
-const isDefinedOrThrow = (v) =>
-  (isDefined(v)
-    ?  () => true
-    : (() => {throw nullOrIndefinedPayload})());
-
-const isValidPayloadOrThrow = (v) =>
-  isDefinedOrThrow(v)()
-    && (isString(v)
-          ? true
-          : isObject(v)
-            ? true
-            : (() => {throw invalidPayloadTypeError})());
-
+// Function
 const asJSON = (v) => (isString(v) ? JSON.parse(v) : v);
 
 /**
@@ -37,7 +24,8 @@ function validateAndParse(payload) {
 
   var json =
     Array.of(payload)
-      .filter(isValidPayloadOrThrow)
+      .filter(p => isDefinedOrThrow(p, nullOrIndefinedPayload))
+      .filter(p => isValidOrThrow(p, invalidPayloadTypeError))
       .map(asJSON)
       .shift();
 
diff --git a/lib/utils/fun.js b/lib/utils/fun.js
index fbbd97b..38dc3a2 100644
--- a/lib/utils/fun.js
+++ b/lib/utils/fun.js
@@ -3,8 +3,23 @@ const isString = (v) => (typeof v) === "string";
 const isObject = (v) => (typeof v) === "object";
 const isDefined = (v) => v && (typeof v) != "undefined";
 
+const isDefinedOrThrow = (v, t) =>
+  (isDefined(v)
+    ?  () => true
+    : (() => {throw t})());
+
+const isValidOrThrow = (v, t) =>
+        (isString(v)
+          ? true
+          : isObject(v)
+            ? true
+            : (() => {throw t})());
+
 module.exports = {
   isString  : isString,
   isObject  : isObject,
-  isDefined : isDefined
+  isDefined : isDefined,
+
+  isDefinedOrThrow : isDefinedOrThrow,
+  isValidOrThrow : isValidOrThrow
 };