fix: check if iterator is a function

src/each.js

@@ -13,7 +13,7 @@ import deflate from './deflate';
 function each(object, iterator, follow = false) {
   // check if the object is an object and isn't empty
   // if it is it would be pointless running the forEach
-  if (is(object) && !empty(object)) {
+  if (is(object) && !empty(object) && typeof iterator === 'function') {
     // if follow is true flatten the object keys so
     // its easy to get the path and values if follow
     // is false it will just be the base object
@@ -27,12 +27,8 @@ function each(object, iterator, follow = false) {
       // get the value of the current key
       const value = flattenedObject[key];
 
-      // check if the iterator is a function
-      if (typeof iterator === 'function') {
-        // if it is run the iterator with the
-        // key and value
-        iterator(key, value);
-      }
+      // run the iterator with the key and value
+      iterator(key, value);
     });
   }
 }

src/every.js

@@ -14,7 +14,7 @@ import each from './each';
  */
 function every(object, iterator, follow = false) {
   // if the object is an object and is not empty
-  if (is(object) && !empty(object)) {
+  if (is(object) && !empty(object) && typeof iterator === 'function') {
     // set the result to true so we can change it
     // to false if the iterator fails
     let result = true;

src/filter.js

@@ -16,7 +16,7 @@ import del from './del';
  */
 function filter(object, iterator, follow = false) {
   // if the object is an object and is not empty
-  if (is(object) && !empty(object)) {
+  if (is(object) && !empty(object) && typeof iterator === 'function') {
     // create a clone of the object to manipulate
     let result = clone(object);
 

src/find.js

@@ -14,7 +14,7 @@ import each from './each';
  */
 function find(object, iterator, follow) {
   // if the object is an object and is not empty
-  if (is(object) && !empty(object)) {
+  if (is(object) && !empty(object) && typeof iterator === 'function') {
     // create an result variable as undefined
     let found = false;
     let result = '';