[#74552] Wrong pane (Backlog/Buckets, not Sprints) autoscrolls

frontend/src/stimulus/controllers/dynamic/generic-drag-and-drop.controller.spec.ts

@@ -70,14 +70,6 @@ describe('GenericDragAndDropController', () => {
     return ariaPressedTarget.call(controller, el);
   }
 
-  function callResolveMirrorContainer():Element {
-    const resolveMirrorContainer = Reflect.get(controller, 'resolveMirrorContainer') as (
-      this:GenericDragAndDropController
-    ) => Element;
-
-    return resolveMirrorContainer.call(controller);
-  }
-
   describe('canStartDrag', () => {
     it('allows dragging a draggable row in handle-less mode', () => {
       const row = draggableRow();
@@ -155,21 +147,4 @@ describe('GenericDragAndDropController', () => {
       expect(callAriaPressedTarget(row)).toBe(handle);
     });
   });
-
-  describe('resolveMirrorContainer', () => {
-    it('returns the configured mirror container target when present', () => {
-      const mirrorContainer = document.createElement('div');
-
-      Object.defineProperty(controller, 'hasMirrorContainerTarget', { value: true, configurable: true });
-      Object.defineProperty(controller, 'mirrorContainerTarget', { value: mirrorContainer, configurable: true });
-
-      expect(callResolveMirrorContainer()).toBe(mirrorContainer);
-    });
-
-    it('falls back to document.body when no mirror container target exists', () => {
-      Object.defineProperty(controller, 'hasMirrorContainerTarget', { value: false, configurable: true });
-
-      expect(callResolveMirrorContainer()).toBe(document.body);
-    });
-  });
 });

frontend/src/stimulus/controllers/dynamic/generic-drag-and-drop.controller.ts

@@ -43,12 +43,10 @@ interface TargetConfig {
 }
 
 export default class GenericDragAndDropController extends Controller {
-  static targets = ['container', 'scrollContainer', 'mirrorContainer'];
+  static targets = ['container', 'scrollContainer'];
 
   containerTargets:HTMLElement[];
   scrollContainerTargets:HTMLElement[];
-  declare readonly hasMirrorContainerTarget:boolean;
-  declare readonly mirrorContainerTarget:HTMLElement;
 
   static values = {
     handle: { type: Boolean, default: true },
@@ -129,7 +127,6 @@ export default class GenericDragAndDropController extends Controller {
         moves: (el, _source, handle, _sibling) => this.canStartDrag(el, handle),
         accepts: (el:Element, target:Element, source:Element, sibling:Element) => this.accepts(el, target, source, sibling),
         revertOnSpill: true, // enable reverting of elements if they are dropped outside of a valid target
-        mirrorContainer: this.resolveMirrorContainer(),
       },
     )
       .on('cloned', (clone, _original, type) => {
@@ -260,10 +257,6 @@ export default class GenericDragAndDropController extends Controller {
     return container;
   }
 
-  private resolveMirrorContainer():Element {
-    return this.hasMirrorContainerTarget ? this.mirrorContainerTarget : document.body;
-  }
-
   // Returns the data-draggable-id of the element preceding el in its container,
   // or null if el is the first item (signals "move to top").
   private resolveTargetPrevious(el:Element):string|null {

modules/backlogs/app/components/backlogs/backlog_bucket_component.rb

@@ -67,7 +67,7 @@ def folded?
 
     def drop_target_config
       {
-        generic_drag_and_drop_target: "container mirrorContainer",
+        generic_drag_and_drop_target: "container",
         target_container_accessor: ":scope > ul",
         target_id: backlog_bucket.persisted? ? "backlog_bucket:#{backlog_bucket.id}" : "inbox",
         target_allowed_drag_type: "story"

modules/backlogs/app/components/backlogs/inbox_component.rb

@@ -97,7 +97,7 @@ def middle_count
 
     def drop_target_config
       {
-        generic_drag_and_drop_target: "container mirrorContainer",
+        generic_drag_and_drop_target: "container",
         target_container_accessor: ":scope > ul",
         target_id: "inbox",
         target_allowed_drag_type: "story"

modules/backlogs/spec/requests/backlogs/backlog_spec.rb

@@ -106,26 +106,6 @@
           expect(response.body).to include('id="sprint_backlogs_container"')
         end
       end
-
-      it "uses the inbox border box as the drag mirror container" do
-        get "/projects/#{project.identifier}/backlogs/backlog", headers: { "Turbo-Frame" => "backlogs_container" }
-
-        expect(response).to have_http_status(:ok)
-        expect(response.body).to include(%(id="inbox_#{project.id}"))
-        expect(response.body).to include('data-generic-drag-and-drop-target="container mirrorContainer"')
-      end
-
-      context "with backlog buckets enabled", with_flag: { backlog_buckets: true } do
-        shared_let(:backlog_bucket) { create(:backlog_bucket, project:) }
-
-        it "uses each backlog bucket border box as the drag mirror container" do
-          get "/projects/#{project.identifier}/backlogs/backlog", headers: { "Turbo-Frame" => "backlogs_container" }
-
-          expect(response).to have_http_status(:ok)
-          expect(response.body).to include(%(data-test-selector="backlog-bucket-#{backlog_bucket.id}"))
-          expect(response.body).to include('data-generic-drag-and-drop-target="container mirrorContainer"')
-        end
-      end
     end
   end