Minor fix to mergeObject and add test for mergeCollection

Author: fabioh8010

lib/storage/providers/IDBKeyValProvider.ts

@@ -53,6 +53,7 @@ const provider: StorageProvider = {
                         shouldRemoveNestedNulls: true,
                         objectRemovalMode: 'replace',
                     }).result;
+
                     return promisifyRequest(store.put(newValue, key));
                 });
                 return Promise.all(upsertMany).then(() => undefined);

lib/storage/providers/MemoryOnlyProvider.ts

@@ -86,10 +86,11 @@ const provider: StorageProvider = {
     multiMerge(pairs) {
         _.forEach(pairs, ([key, value]) => {
             const existingValue = store[key] as Record<string, unknown>;
+
             const newValue = utils.fastMerge(existingValue, value as Record<string, unknown>, {
                 shouldRemoveNestedNulls: true,
                 objectRemovalMode: 'replace',
-            }).result as OnyxValue<OnyxKey>;
+            }).result;
 
             set(key, newValue);
         });

lib/utils.ts

@@ -135,9 +135,11 @@ function mergeObject<TObject extends Record<string, unknown>>(
         // has the internal flag set, we replace the entire destination object with the source one and remove
         // the flag.
         if (options.objectRemovalMode === 'replace' && sourceProperty[ONYX_INTERNALS__REPLACE_OBJECT_MARK]) {
-            // eslint-disable-next-line @typescript-eslint/no-unused-vars
-            delete sourceProperty[ONYX_INTERNALS__REPLACE_OBJECT_MARK];
-            destination[key] = sourceProperty;
+            // We do a spread here in order to have a new object reference and allow us to delete the internal flag
+            // of the merged object only.
+            const sourcePropertyWithoutMark = {...sourceProperty};
+            delete sourcePropertyWithoutMark.ONYX_INTERNALS__REPLACE_OBJECT_MARK;
+            destination[key] = sourcePropertyWithoutMark;
             return;
         }
 

tests/unit/onyxTest.ts

@@ -1930,6 +1930,86 @@ describe('Onyx', () => {
 
                 expect(result).toEqual({[`${ONYX_KEYS.COLLECTION.TEST_UPDATE}entry1`]: entry1ExpectedResult});
             });
+
+            describe('mergeCollection', () => {
+                it('replacing old object after null merge', async () => {
+                    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+                    const entry1: DeepRecord<string, any> = {
+                        sub_entry1: {
+                            id: 'sub_entry1',
+                            someKey: 'someValue',
+                        },
+                    };
+                    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+                    const entry2: DeepRecord<string, any> = {
+                        sub_entry2: {
+                            id: 'sub_entry2',
+                            someKey: 'someValue',
+                        },
+                    };
+                    await Onyx.multiSet({[`${ONYX_KEYS.COLLECTION.TEST_UPDATE}entry1`]: entry1});
+                    await Onyx.multiSet({[`${ONYX_KEYS.COLLECTION.TEST_UPDATE}entry2`]: entry2});
+
+                    const entry1ExpectedResult = lodashCloneDeep(entry1);
+                    const entry2ExpectedResult = lodashCloneDeep(entry2);
+                    const queuedUpdates: OnyxUpdate[] = [];
+
+                    queuedUpdates.push(
+                        {
+                            key: `${ONYX_KEYS.COLLECTION.TEST_UPDATE}entry1`,
+                            onyxMethod: 'merge',
+                            value: {
+                                // Removing the "sub_entry1" object in this update.
+                                // Any subsequent changes to this object should completely replace the existing object in store.
+                                sub_entry1: null,
+                            },
+                        },
+                        {
+                            key: `${ONYX_KEYS.COLLECTION.TEST_UPDATE}entry2`,
+                            onyxMethod: 'merge',
+                            value: {
+                                // Removing the "sub_entry2" object in this update.
+                                // Any subsequent changes to this object should completely replace the existing object in store.
+                                sub_entry2: null,
+                            },
+                        },
+                    );
+                    delete entry1ExpectedResult.sub_entry1;
+                    delete entry2ExpectedResult.sub_entry2;
+
+                    queuedUpdates.push(
+                        {
+                            key: `${ONYX_KEYS.COLLECTION.TEST_UPDATE}entry1`,
+                            onyxMethod: 'merge',
+                            value: {
+                                // This change should completely replace "sub_entry1" existing object in store.
+                                sub_entry1: {
+                                    newKey: 'newValue',
+                                },
+                            },
+                        },
+                        {
+                            key: `${ONYX_KEYS.COLLECTION.TEST_UPDATE}entry2`,
+                            onyxMethod: 'merge',
+                            value: {
+                                // This change should completely replace "sub_entry2" existing object in store.
+                                sub_entry2: {
+                                    newKey: 'newValue',
+                                },
+                            },
+                        },
+                    );
+                    entry1ExpectedResult.sub_entry1 = {newKey: 'newValue'};
+                    entry2ExpectedResult.sub_entry2 = {newKey: 'newValue'};
+
+                    await Onyx.update(queuedUpdates);
+
+                    expect(result).toEqual({
+                        [`${ONYX_KEYS.COLLECTION.TEST_UPDATE}entry1`]: entry1ExpectedResult,
+                        [`${ONYX_KEYS.COLLECTION.TEST_UPDATE}entry2`]: entry2ExpectedResult,
+                    });
+                });
+            });
         });
 
         describe('merge', () => {