fix(tasks): preserve schedule when moving between backlog and regular list (#8603)

Moving a task between the backlog and the regular list now only changes its
list position. Previously, moving to the regular list force-scheduled the task
for today (planTasksForToday) and moving to the backlog cleared a schedule that
fell on today, so the task's due date silently changed.

Fixes #8592

src/app/features/tasks/task-context-menu/task-context-menu-inner/task-context-menu-inner.component.spec.ts

@@ -18,6 +18,8 @@ import { DateAdapter } from '@angular/material/core';
 import { of } from 'rxjs';
 import { selectTaskByIdWithSubTaskData } from '../../store/task.selectors';
 import { addSubTask } from '../../store/task.actions';
+import { TaskSharedActions } from '../../../../root-store/meta/task-shared.actions';
+import { DateService } from '../../../../core/date/date.service';
 import { NoopAnimationsModule } from '@angular/platform-browser/animations';
 import { AddSubtaskInputService } from '../../add-subtask-input/add-subtask-input.service';
 import { Project } from '../../../project/project.model';
@@ -89,6 +91,8 @@ describe('TaskContextMenuInnerComponent', () => {
                 projectInTreeOrder('project-a', 'Project A'),
               ]),
             getByIdOnce$: () => of({}),
+            moveTaskToTodayList: () => {},
+            moveTaskToBacklog: () => {},
           },
         },
         {
@@ -339,4 +343,51 @@ describe('TaskContextMenuInnerComponent', () => {
       expect(addSubtaskInputService.requestOpen).toHaveBeenCalledWith('PARENT_ID');
     });
   });
+
+  // Moving a task between the backlog and the regular list is a list-position
+  // change only; it must not touch the task's schedule (issue #8592).
+  describe('moveToToday() / moveToBacklog() schedule preservation (#8592)', () => {
+    let projectService: ProjectService;
+
+    beforeEach(() => {
+      projectService = TestBed.inject(ProjectService);
+    });
+
+    it('moveToToday() moves to the regular list without scheduling for today', () => {
+      const moveSpy = spyOn(projectService, 'moveTaskToTodayList');
+      const dispatchSpy = spyOn(store, 'dispatch');
+      component.task = {
+        ...DEFAULT_TASK,
+        id: 'task-1',
+        projectId: 'project-current',
+      } as Task;
+
+      component.moveToToday();
+
+      expect(moveSpy).toHaveBeenCalledWith('task-1', 'project-current');
+      const dispatchedTypes = dispatchSpy.calls
+        .allArgs()
+        .map((args) => (args[0] as unknown as { type: string }).type);
+      expect(dispatchedTypes).not.toContain(TaskSharedActions.planTasksForToday.type);
+    });
+
+    it('moveToBacklog() moves to the backlog without clearing a schedule set for today', () => {
+      const moveSpy = spyOn(projectService, 'moveTaskToBacklog');
+      const dispatchSpy = spyOn(store, 'dispatch');
+      component.task = {
+        ...DEFAULT_TASK,
+        id: 'task-1',
+        projectId: 'project-current',
+        dueDay: TestBed.inject(DateService).todayStr(),
+      } as Task;
+
+      component.moveToBacklog();
+
+      expect(moveSpy).toHaveBeenCalledWith('task-1', 'project-current');
+      const dispatchedTypes = dispatchSpy.calls
+        .allArgs()
+        .map((args) => (args[0] as unknown as { type: string }).type);
+      expect(dispatchedTypes).not.toContain(TaskSharedActions.unscheduleTask.type);
+    });
+  });
 });

src/app/features/tasks/task-context-menu/task-context-menu-inner/task-context-menu-inner.component.ts

@@ -674,20 +674,17 @@ export class TaskContextMenuInnerComponent implements AfterViewInit, OnDestroy {
 
   moveToBacklog(): void {
     if (this.task.projectId && !this.task.parentId) {
+      // Moving to the backlog is a list-position change only; it must not
+      // alter the task's schedule (#8592).
       this._projectService.moveTaskToBacklog(this.task.id, this.task.projectId);
-      if (
-        this.task.dueDay === this._dateService.todayStr() ||
-        (this.task.dueWithTime && this._dateService.isToday(this.task.dueWithTime))
-      ) {
-        this.unschedule();
-      }
     }
   }
 
   moveToToday(): void {
     if (this.task.projectId && !this.task.parentId) {
+      // Moving to the regular list is a list-position change only; it must not
+      // schedule the task for today (#8592).
       this._projectService.moveTaskToTodayList(this.task.id, this.task.projectId);
-      this.addToMyDay();
     }
   }
 

src/app/features/tasks/task/task.component.ts

@@ -230,9 +230,6 @@ export class TaskComponent implements OnDestroy, AfterViewInit {
     return 'chat';
   });
 
-  isTaskOnTodayList = computed(() =>
-    this._taskService.todayListSet().has(this.task().id),
-  );
   isTodayListActive = computed(() => this.workContextService.isTodayList);
   taskIdWithPrefix = computed(() => 't-' + this.task().id);
   isRepeatTaskCreatedToday = computed(
@@ -1335,18 +1332,18 @@ export class TaskComponent implements OnDestroy, AfterViewInit {
   moveToBacklog(): void {
     const t = this.task();
     if (t.projectId && !t.parentId) {
+      // Moving to the backlog is a list-position change only; it must not
+      // alter the task's schedule (#8592).
       this._projectService.moveTaskToBacklog(t.id, t.projectId);
-      if (this.isTaskOnTodayList()) {
-        this.unschedule();
-      }
     }
   }
 
   moveToToday(): void {
     const t = this.task();
     if (t.projectId) {
+      // Moving to the regular list is a list-position change only; it must not
+      // schedule the task for today (#8592).
       this._projectService.moveTaskToTodayList(t.id, t.projectId);
-      this.addToMyDay();
     }
   }