Got tests running on single property character

app/imports/api/creature/computation/newEngine/utility/applyFnToKey.js

@@ -1,7 +1,7 @@
 import { get } from 'lodash';
 
-export function applyFnToKey(doc, key, fn){
-  if (key.includes('$.')){
+export default function applyFnToKey(doc, key, fn){
+  if (key.includes('.$')){
     applyToArrayKey(doc, key, fn);
   } else {
     applyToSingleKey(doc, key, fn);
@@ -16,26 +16,31 @@ function applyToSingleKey(doc, key, fn){
 /**
  * Applies the given function to all instances in a document key
  * key.$.with.$.subdocs will apply to all key[i...n].with[j...m].subdocs
+ * Warning: Order might be confusing, it will traverse the deepest array in order
+ * but the shallower arrays in reverse order
  */
 function applyToArrayKey(doc, key, fn){
   const keySplit = key.split('.$');
-
   // Stack based depth first traversal of arrays
+  const array = get(doc, keySplit[0]);
+  if (!array) return;
   const stack = [{
-    array: get(doc, keySplit[0]),
+    array,
     paths: keySplit.slice(1),
     currentPath: keySplit[0],
     indices: [],
   }];
   while(stack.length){
     const state = stack.pop();
-    for (let index in state.array.length){
+    for (let index in state.array){
       const currentPath = `${state.currentPath}[${index}]${state.paths[0]}`
       if (state.paths.length == 1){
         applyToSingleKey(doc, currentPath, fn);
       } else {
+        const array = get(doc, currentPath);
+        if (!array) return;
         stack.push({
-          array: get(doc, currentPath),
+          array,
           paths: state.paths.slice(1),
           currentPath,
           indices: [...state.indices, index],