Rework sortable-lists topology and enable optimistic 204 moves

frontend/src/stimulus/controllers/dynamic/backlogs/split-view-sync.controller.spec.ts

@@ -33,6 +33,7 @@ import { setupStimulusTest, type StimulusTestContext } from 'core-stimulus/test-
 import type SplitViewSyncControllerType from './split-view-sync.controller';
 
 const MOVED_EVENT = 'op-dispatched:backlogs:work-package-moved';
+const SORTABLE_MOVED_EVENT = 'sortable-lists:moved';
 
 describe('Backlogs split-view-sync controller', () => {
   let ctx:StimulusTestContext;
@@ -77,7 +78,7 @@ describe('Backlogs split-view-sync controller', () => {
   async function renderHost() {
     await ctx.mount(`
       <div data-controller="backlogs--split-view-sync"
-           data-action="${MOVED_EVENT}@document->backlogs--split-view-sync#onWorkPackageMoved"></div>
+           data-action="${MOVED_EVENT}@document->backlogs--split-view-sync#onWorkPackageMoved ${SORTABLE_MOVED_EVENT}@document->backlogs--split-view-sync#onSortableListsMoved"></div>
     `);
     const host = ctx.container.querySelector<HTMLElement>('[data-controller="backlogs--split-view-sync"]')!;
 
@@ -91,6 +92,10 @@ describe('Backlogs split-view-sync controller', () => {
     document.dispatchEvent(new CustomEvent(MOVED_EVENT, { detail }));
   }
 
+  function dispatchSortableMoved(detail:object) {
+    document.dispatchEvent(new CustomEvent(SORTABLE_MOVED_EVENT, { detail }));
+  }
+
   it('refreshes the moved work package cache when it is loaded', async () => {
     await renderHost();
 
@@ -158,4 +163,25 @@ describe('Backlogs split-view-sync controller', () => {
 
     expect(refresh).not.toHaveBeenCalled();
   });
+
+  it('refreshes a cached work package on sortable-lists:moved', async () => {
+    await renderHost();
+
+    dispatchSortableMoved({ itemId: '1234' });
+
+    await waitFor(() => {
+      expect(state).toHaveBeenCalledWith('1234');
+      expect(id).toHaveBeenCalledWith('1234');
+      expect(refresh).toHaveBeenCalled();
+    });
+  });
+
+  it('ignores a sortable-lists:moved event without an item id', async () => {
+    await renderHost();
+
+    dispatchSortableMoved({});
+    await ctx.nextFrame();
+
+    expect(refresh).not.toHaveBeenCalled();
+  });
 });

frontend/src/stimulus/controllers/dynamic/backlogs/split-view-sync.controller.ts

@@ -32,9 +32,12 @@ import { useAngularServices, type ServiceKey } from 'core-stimulus/mixins/use-an
 
 // A split view open on a moved work package caches the lock_version it fetched
 // on opening, so the next edit after a move would fail with a
-// conflicting-modifications error. The server signals every successful move via
-// a document event; this controller refreshes the moved work package in the
-// Angular cache so the split view stays editable.
+// conflicting-modifications error. Every successful move is signalled via a
+// document event, either dispatched by the server (cross-list moves) or by
+// the client-side sortable-lists controller (same-list moves, which resolve
+// with a 204 and never reach the server-dispatched event); this controller
+// refreshes the moved work package in the Angular cache so the split view
+// stays editable.
 export default class SplitViewSyncController extends Controller {
   static services:ServiceKey[] = ['apiV3Service'];
 
@@ -55,11 +58,25 @@ export default class SplitViewSyncController extends Controller {
   // is correct as well.
   onWorkPackageMoved(event:CustomEvent<{ work_package_id?:number }>):void {
     const workPackageId = event.detail?.work_package_id;
-    // apiV3Service is wired asynchronously via useAngularServices, so it may be absent
-    // if the event somehow fires before the services resolve.
-    if (workPackageId === undefined || !this.apiV3Service) { return; }
+    if (workPackageId === undefined) { return; }
+    this.refreshWorkPackage(workPackageId.toString());
+  }
+
+  // Bound to the client-dispatched `sortable-lists:moved` document event. Same
+  // refresh as onWorkPackageMoved: optimistic same-list moves answer with 204,
+  // so no server-dispatched moved event exists on that path. On cross-list
+  // moves both events fire; the double refresh is idempotent.
+  onSortableListsMoved(event:CustomEvent<{ itemId?:string }>):void {
+    const itemId = event.detail?.itemId;
+    if (itemId === undefined) { return; }
+    this.refreshWorkPackage(itemId);
+  }
+
+  private refreshWorkPackage(id:string):void {
+    // apiV3Service is wired asynchronously via useAngularServices, so it may be
+    // absent if an event somehow fires before the services resolve.
+    if (!this.apiV3Service) { return; }
 
-    const id = workPackageId.toString();
     const { work_packages: workPackages } = this.apiV3Service;
 
     if (workPackages.cache.state(id).hasValue()) {