refactor(web): centralize multi-select release handling

apps/web/src/hooks/timelineMultiSelect.test.ts

@@ -1,5 +1,6 @@
 import { describe, expect, it } from "vitest";
 import {
+  completeMultiSelectDraft,
   createMultiSelectState,
   finalizeMultiSelectDraft,
   updateMultiSelectDraft,
@@ -98,4 +99,67 @@ describe("timelineMultiSelect", () => {
       currentY: 295,
     });
   });
+
+  it("returns the provided empty state when the right-click drag never really started", () => {
+    const state = createMultiSelectState<TestMultiSelectState>(120, 240, {
+      selectedAllocationIds: ["alloc-1"],
+      selectedResourceIds: ["res-1"],
+      dateRange: null,
+      multiDragDaysDelta: 1,
+      isMultiDragging: true,
+      multiDragMode: "move",
+    });
+    const emptyState: TestMultiSelectState = {
+      isSelecting: false,
+      startX: 0,
+      startY: 0,
+      currentX: 0,
+      currentY: 0,
+      selectedAllocationIds: [],
+      selectedResourceIds: [],
+      dateRange: null,
+      multiDragDaysDelta: 0,
+      isMultiDragging: false,
+      multiDragMode: "move",
+    };
+
+    expect(completeMultiSelectDraft(state, 123, 243, emptyState)).toEqual({
+      nextState: emptyState,
+      shouldClear: true,
+    });
+  });
+
+  it("keeps the finished rectangle when the drag cleared the minimum distance", () => {
+    const state = createMultiSelectState<TestMultiSelectState>(120, 240, {
+      selectedAllocationIds: [],
+      selectedResourceIds: [],
+      dateRange: null,
+      multiDragDaysDelta: 0,
+      isMultiDragging: false,
+      multiDragMode: "move",
+    });
+    const emptyState: TestMultiSelectState = {
+      isSelecting: false,
+      startX: 0,
+      startY: 0,
+      currentX: 0,
+      currentY: 0,
+      selectedAllocationIds: [],
+      selectedResourceIds: [],
+      dateRange: null,
+      multiDragDaysDelta: 0,
+      isMultiDragging: false,
+      multiDragMode: "move",
+    };
+
+    expect(completeMultiSelectDraft(state, 150, 295, emptyState)).toEqual({
+      nextState: {
+        ...state,
+        isSelecting: false,
+        currentX: 150,
+        currentY: 295,
+      },
+      shouldClear: false,
+    });
+  });
 });

apps/web/src/hooks/timelineMultiSelect.ts

@@ -65,3 +65,24 @@ export function finalizeMultiSelectDraft<TState extends MultiSelectStateLike>(
     currentY,
   };
 }
+
+export function completeMultiSelectDraft<TState extends MultiSelectStateLike>(
+  state: TState,
+  currentX: number,
+  currentY: number,
+  emptyState: TState,
+  minDistancePx = 5,
+): { nextState: TState; shouldClear: boolean } {
+  const finished = finalizeMultiSelectDraft(state, currentX, currentY, minDistancePx);
+  if (!finished) {
+    return {
+      nextState: emptyState,
+      shouldClear: true,
+    };
+  }
+
+  return {
+    nextState: finished,
+    shouldClear: false,
+  };
+}

apps/web/src/hooks/useTimelineDrag.ts

@@ -23,8 +23,8 @@ import { createAllocationDragState } from "./timelineAllocationDragState.js";
 import { attachDocumentMouseDrag } from "./timelineDocumentDrag.js";
 import { buildProjectShiftMutationInput, createProjectDragState } from "./timelineProjectDrag.js";
 import {
+  completeMultiSelectDraft,
   createMultiSelectState,
-  finalizeMultiSelectDraft,
   updateMultiSelectDraft,
 } from "./timelineMultiSelect.js";
 import { reconcileOptimisticEntries } from "./timelineOptimisticAllocations.js";
@@ -896,21 +896,9 @@ export function useTimelineDrag({
       const ms = multiSelectRef.current;
       if (!ms.isSelecting) return;
 
-      const finished = finalizeMultiSelectDraft(ms, ev.clientX, ev.clientY);
-      if (!finished) {
-        // Minimal movement → not a drag selection, reset.
-        // Let existing onContextMenu handlers on allocation blocks handle right-click.
-        multiSelectRef.current = INITIAL_MULTI_SELECT;
-        setMultiSelectState(INITIAL_MULTI_SELECT);
-        return;
-      }
-
-      // Keep the rectangle coordinates for the parent to compute intersection.
-      // isSelecting is set to false to indicate the drag is done, but the
-      // rectangle data (startX/Y, currentX/Y) is preserved so TimelineView
-      // can resolve which allocations/resources fall within the selection.
-      multiSelectRef.current = finished;
-      setMultiSelectState(finished);
+      const result = completeMultiSelectDraft(ms, ev.clientX, ev.clientY, INITIAL_MULTI_SELECT);
+      multiSelectRef.current = result.nextState;
+      setMultiSelectState(result.nextState);
     }
 
     multiSelectCleanupRef.current = attachDocumentMouseDrag(document, handleMove, handleUp);