add addRecords and add test on data GET_MANY_REFERENCE and GET_MANY a…

…ction

packages/ra-core/src/reducer/admin/resource/data.spec.ts

@@ -1,8 +1,15 @@
 import assert from 'assert';
 
-import { DELETE, DELETE_MANY, UPDATE } from '../../../core';
+import {
+    DELETE,
+    DELETE_MANY,
+    UPDATE,
+    GET_MANY,
+    GET_MANY_REFERENCE,
+} from '../../../core';
 import getFetchedAt from '../../../util/getFetchedAt';
 import dataReducer, { replaceRecords, addOneRecord } from './data';
+import { FETCH_END } from '../../../actions';
 
 jest.mock('../../../util/getFetchedAt');
 
@@ -253,4 +260,53 @@ describe('Resources data reducer', () => {
             assert.notDeepEqual(newState.fetchedAt.record2, before);
         });
     });
+
+    describe.each([GET_MANY_REFERENCE, GET_MANY])('%s', actionType => {
+        it('should add new records to the old one', () => {
+            const before = new Date(0);
+            const now = new Date();
+
+            // @ts-ignore
+            getFetchedAt.mockImplementationOnce(() => ({
+                new_record: now,
+                record2: now,
+            }));
+
+            const state = {
+                record1: { id: 'record1', prop: 'value' },
+                record2: { id: 'record2', prop: 'value' },
+                record3: { id: 'record3', prop: 'value' },
+                fetchedAt: {
+                    record1: before,
+                    record2: before,
+                    record3: before,
+                },
+            };
+
+            const newState = dataReducer(state, {
+                type: actionType,
+                payload: {
+                    data: [
+                        { id: 'record2', prop: 'updated value' },
+                        { id: 'new_record', prop: 'new value' },
+                    ],
+                },
+                meta: {
+                    fetchResponse: actionType,
+                    fetchStatus: FETCH_END,
+                },
+            });
+            assert.deepEqual(newState, {
+                record1: { id: 'record1', prop: 'value' },
+                record2: { id: 'record2', prop: 'updated value' },
+                record3: { id: 'record3', prop: 'value' },
+                new_record: { id: 'new_record', prop: 'new value' },
+            });
+            assert.deepEqual(newState.fetchedAt.record1, before);
+            assert.deepEqual(newState.fetchedAt.record3, before);
+
+            assert.notDeepEqual(newState.fetchedAt.record2, before);
+            assert.notDeepEqual(newState.fetchedAt.new_record, before);
+        });
+    });
 });

packages/ra-core/src/reducer/admin/resource/data.ts

@@ -86,6 +86,34 @@ export const replaceRecords = (
 
     return hideFetchedAt(records);
 };
+
+/**
+ * Add new records to the pool, without touching the other ones.
+ */
+export const addRecords = (
+    newRecords: Record[] = [],
+    oldRecords: RecordSetWithDate
+): RecordSetWithDate => {
+    const newRecordsById = { ...oldRecords };
+    newRecords.forEach(record => {
+        newRecordsById[record.id] = isEqual(record, oldRecords[record.id])
+            ? (oldRecords[record.id] as Record)
+            : record;
+    });
+
+    const updatedFetchedAt = getFetchedAt(
+        newRecords.map(({ id }) => id),
+        oldRecords.fetchedAt
+    );
+
+    Object.defineProperty(newRecordsById, 'fetchedAt', {
+        value: { ...oldRecords.fetchedAt, ...updatedFetchedAt },
+        enumerable: false,
+    });
+
+    return newRecordsById;
+};
+
 export const addOneRecord = (
     newRecord: Record,
     oldRecords: RecordSetWithDate,
@@ -160,10 +188,7 @@ const dataReducer: Reducer<RecordSetWithDate> = (
             return replaceRecords(payload.data, previousState);
         case GET_MANY:
         case GET_MANY_REFERENCE:
-            return replaceRecords(
-                Object.values(previousState).concat(payload.data) as Record[],
-                previousState
-            );
+            return addRecords(payload.data, previousState);
         case UPDATE:
         case CREATE:
         case GET_ONE: