Update task state version after execution. (#215559)

This PR fixes the missing stateVersion update in the `partialUpdate`
method.


[update](https://github.com/elastic/kibana/blob/main/x-pack/platform/plugins/shared/task_manager/server/buffered_task_store.ts#L62)
method already uses the validated task that already has the stateVersion
field.

but the `partialUpdate` misses it.

x-pack/platform/plugins/shared/task_manager/server/buffered_task_store.test.ts

@@ -375,5 +375,26 @@ describe('Buffered Task Store', () => {
       expect(await results[2]).toMatchObject(partialTasks[2]);
       expect(await results[3]).toMatchObject(partialTasks[3]);
     });
+
+    test(`updates the stateVersion`, async () => {
+      const taskStore = taskStoreMock.create({ stateVersion: 2 });
+      const bufferedStore = new BufferedTaskStore(taskStore, {});
+
+      const task = taskManagerMock.createTask();
+      const partialTask = {
+        id: task.id,
+        version: task.version,
+        status: 'running' as TaskStatus,
+      };
+
+      taskStore.bulkPartialUpdate.mockResolvedValue([asOk(partialTask)]);
+
+      expect(
+        await bufferedStore.partialUpdate(partialTask, { validate: false, doc: task })
+      ).toMatchObject(partialTask);
+      expect(taskStore.bulkPartialUpdate).toHaveBeenCalledWith([
+        { ...partialTask, stateVersion: 2 },
+      ]);
+    });
   });
 });

x-pack/platform/plugins/shared/task_manager/server/buffered_task_store.ts

@@ -73,12 +73,14 @@ export class BufferedTaskStore implements Updatable {
     options: { validate: boolean; doc: ConcreteTaskInstance }
   ): Promise<ConcreteTaskInstance> {
     // merge the partial updates with the doc and validate
-    this.taskStore.taskValidator.getValidatedTaskInstanceForUpdating(
+    const { stateVersion } = this.taskStore.taskValidator.getValidatedTaskInstanceForUpdating(
       { ...options.doc, ...partialDoc },
       { validate: options.validate }
     );
 
-    const result = await unwrapPromise(this.bufferedPartialUpdate(partialDoc));
+    const result = await unwrapPromise(
+      this.bufferedPartialUpdate({ ...partialDoc, ...(stateVersion ? { stateVersion } : {}) })
+    );
 
     // merge the partial update result with the doc and validate
     return this.taskStore.taskValidator.getValidatedTaskInstanceFromReading(

x-pack/platform/plugins/shared/task_manager/server/task_store.mock.ts

@@ -11,13 +11,16 @@ import { TaskStore } from './task_store';
 interface TaskStoreOptions {
   index?: string;
   taskManagerId?: string;
+  stateVersion?: number;
 }
 export const taskStoreMock = {
-  create({ index = '', taskManagerId = '' }: TaskStoreOptions = {}) {
+  create({ index = '', taskManagerId = '', stateVersion }: TaskStoreOptions = {}) {
     const mocked = {
       taskValidator: {
         getValidatedTaskInstanceFromReading: jest.fn().mockImplementation((task) => task),
-        getValidatedTaskInstanceForUpdating: jest.fn().mockImplementation((task) => task),
+        getValidatedTaskInstanceForUpdating: jest
+          .fn()
+          .mockImplementation((task) => ({ ...task, ...(stateVersion ? { stateVersion } : {}) })),
       },
       convertToSavedObjectIds: jest.fn(),
       update: jest.fn(),