Add missing file, use it in default keys

Author: iwiznia

lib/Onyx.js

@@ -734,7 +734,7 @@ function initializeWithDefaultKeyStates() {
         .then((pairs) => {
             const asObject = _.object(pairs);
 
-            const merged = lodashMerge(asObject, defaultKeyStates);
+            const merged = lodashMergeWith(asObject, defaultKeyStates, customizerForMergeWith);
             cache.merge(merged);
             _.each(merged, (val, key) => keyChanged(key, val));
         });

lib/customizerForMergeWith.js

@@ -0,0 +1,21 @@
+import _ from "underscore";
+
+/**
+ * When merging 2 objects into onyx that contain an array, we want to completely replace the array instead of the default
+ * behavior which is to merge each item by its index.
+ * ie:
+ * merge({a: [1]}, {a: [2,3]}):
+ *  - In the default implementation would produce {a:[1,3]}
+ *  - With this function would produce: {a: [2,3]}
+ * @param {*} objValue
+ * @param {*} srcValue
+ * @return {*}
+ */
+// eslint-disable-next-line rulesdir/prefer-early-return
+function customizerForMergeWith(objValue, srcValue) {
+    if (_.isArray(objValue)) {
+        return srcValue;
+    }
+}
+
+export default customizerForMergeWith;