Fix: SQLite causes crash when trying to merge undefined

lib/Onyx.js

@@ -9,6 +9,7 @@ import fastMerge from './fastMerge';
 import * as PerformanceUtils from './metrics/PerformanceUtils';
 import Storage from './storage';
 import DevTools from './DevTools';
+import Utils from './utils';
 
 // Method constants
 const METHOD = {
@@ -962,7 +963,7 @@ function removeNullObjectValues(value) {
  * @returns {Promise}
  */
 function set(key, value) {
-    if (_.isNull(value)) {
+    if (_.isUndefined(value) || _.isNull(value)) {
         return remove(key);
     }
 
@@ -1044,11 +1045,21 @@ function applyMerge(existingValue, changes) {
         return lastChange;
     }
 
-    if (_.isObject(existingValue) || _.every(changes, _.isObject)) {
+    if (_.isObject(existingValue) || _.isObject(lastChange)) {
+        // We want to merge multiple object delates together
+        // If all of the changes are objects, we can simply merge all of them together
+        // If the batched changes contain nullish values or arrays, we should only merge the very last objects in the batch
+        let numberOfObjectsAtEndOfArray;
+        if (_.every(changes, _.isObject)) {
+            numberOfObjectsAtEndOfArray = changes.length;
+        } else {
+            numberOfObjectsAtEndOfArray = Utils.countObjectsAtEndOfArray(changes);
+        }
+
         // Object values are merged one after the other
         // lodash adds a small overhead so we don't use it here
         // eslint-disable-next-line prefer-object-spread, rulesdir/prefer-underscore-method
-        return _.reduce(changes, (modifiedData, change) => fastMerge(modifiedData, change),
+        return _.reduce(changes.slice(-numberOfObjectsAtEndOfArray), (modifiedData, change) => fastMerge(modifiedData, change),
             existingValue || {});
     }
 
@@ -1092,6 +1103,10 @@ function merge(key, changes) {
                 // We first only merge the changes, so we can provide these to the native implementation (SQLite uses only delta changes in "JSON_PATCH" to merge)
                 let batchedChanges = applyMerge(undefined, mergeQueue[key]);
 
+                if (_.isUndefined(batchedChanges) || _.isNull(batchedChanges)) {
+                    return remove(key);
+                }
+
                 // Clean up the write queue so we
                 // don't apply these changes again
                 delete mergeQueue[key];

lib/storage/providers/SQLiteStorage.js

@@ -88,10 +88,12 @@ const provider = {
              ON CONFLICT DO UPDATE
              SET valueJSON = JSON_PATCH(valueJSON, JSON(:value));
         `;
+
         const queryArguments = _.map(pairs, (pair) => {
-            const value = JSON.stringify(pair[1]);
-            return [pair[0], value];
+            const value = pair[1];
+            return [pair[0], JSON.stringify(value)];
         });
+
         return db.executeBatchAsync([[query, queryArguments]]);
     },
 

lib/utils.js

@@ -0,0 +1,13 @@
+function countObjectsAtEndOfArray(array) {
+    let count = 0;
+    for (let i = array.length - 1; i >= 0; i--) {
+        if (typeof array[i] === 'object' && array[i] !== null) {
+            count++;
+        } else {
+            break;
+        }
+    }
+    return count;
+}
+
+export default {countObjectsAtEndOfArray};