fix(i18n): allow to store the new entry in the draft after a pre save

packages/decap-cms-core/src/__tests__/backend.spec.js

@@ -318,6 +318,79 @@ describe('Backend', () => {
     });
   });
 
+  describe('persistEntry', () => {
+    it('should update the draft with the new entry returned by preSave event', async () => {
+      const implementation = {
+        init: jest.fn(() => implementation),
+        persistEntry: jest.fn(() => implementation),
+      };
+
+      const config = {
+        backend: {
+          commit_messages:"commit-messages"
+      } };
+      const collection = Map({
+        name: 'posts',
+      });
+      const entry = Map({
+        data: 'old_data'
+      });
+      const newEntry = Map({
+        data: 'new_data'
+      });
+      const entryDraft = Map({
+        entry: entry
+      });
+      const user = { login: 'login', name: 'name' };
+      const backend = new Backend(implementation, { config, backendName: 'github' });
+
+      backend.currentUser = jest.fn().mockResolvedValue(user);      
+      backend.entryToRaw = jest.fn().mockReturnValue('content');
+      backend.invokePreSaveEvent = jest.fn().mockReturnValueOnce(newEntry);
+
+      await backend.persistEntry({ config, collection, entryDraft });
+
+      expect(backend.entryToRaw).toHaveBeenCalledTimes(1);
+      expect(backend.entryToRaw).toHaveBeenCalledWith(collection, newEntry);
+    });
+
+    it('should update the draft with the new data returned by preSave event', async () => {
+      const implementation = {
+        init: jest.fn(() => implementation),
+        persistEntry: jest.fn(() => implementation),
+      };
+
+      const config = {
+        backend: {
+          commit_messages:"commit-messages"
+      } };
+      const collection = Map({
+        name: 'posts',
+      });
+      const entry = Map({
+        data: Map({})
+      });
+      const newData = Map({});
+      const newEntry = Map({
+        data: newData
+      });
+      const entryDraft = Map({
+        entry: entry
+      });
+      const user = { login: 'login', name: 'name' };
+      const backend = new Backend(implementation, { config, backendName: 'github' });
+
+      backend.currentUser = jest.fn().mockResolvedValue(user);      
+      backend.entryToRaw = jest.fn().mockReturnValue('content');
+      backend.invokePreSaveEvent = jest.fn().mockReturnValueOnce(newData);
+
+      await backend.persistEntry({ config, collection, entryDraft });
+
+      expect(backend.entryToRaw).toHaveBeenCalledTimes(1);
+      expect(backend.entryToRaw).toHaveBeenCalledWith(collection, newEntry);
+    });
+  });
+
   describe('persistMedia', () => {
     it('should persist media', async () => {
       const persistMediaResult = {};

packages/decap-cms-core/src/backend.ts

@@ -1091,8 +1091,14 @@ export class Backend {
     unpublished = false,
     status,
   }: PersistArgs) {
-    const modifiedData = await this.invokePreSaveEvent(draft.get('entry'));
-    const entryDraft = (modifiedData && draft.setIn(['entry', 'data'], modifiedData)) || draft;
+    const updatedEntity = await this.invokePreSaveEvent(draft.get('entry'));
+
+    let entryDraft;
+    if (updatedEntity.get('data') === undefined) {
+      entryDraft = (updatedEntity && draft.setIn(['entry', 'data'], updatedEntity)) || draft;
+    } else {
+      entryDraft = (updatedEntity && draft.setIn(['entry'], updatedEntity)) || draft;
+    }
 
     const newEntry = entryDraft.getIn(['entry', 'newRecord']) || false;