fix: ensure sheet order unique (#6295)

packages/core/src/sheets/workbook.ts

@@ -180,6 +180,7 @@ export class Workbook extends UnitModel<IWorkbookData, UniverInstanceType.UNIVER
 
         sheets[id] = worksheetSnapshot;
         sheetOrder.splice(index, 0, id);
+        this.ensureSheetOrderUnique();
         const worksheet = new Worksheet(this._unitId, worksheetSnapshot, this._styles);
         this._worksheets.set(id, worksheet);
         this._sheetCreated$.next(worksheet);
@@ -191,6 +192,22 @@ export class Workbook extends UnitModel<IWorkbookData, UniverInstanceType.UNIVER
         return this._snapshot.sheetOrder;
     }
 
+    // Ensure sheet order is unique
+    ensureSheetOrderUnique() {
+        const seen = new Set<string>();
+        const result: string[] = [];
+
+        for (const item of this._snapshot.sheetOrder) {
+            if (!seen.has(item)) {
+                seen.add(item);
+                result.push(item);
+            }
+        }
+
+        this._snapshot.sheetOrder = result;
+        seen.clear();
+    }
+
     getWorksheets(): Map<string, Worksheet> {
         return this._worksheets;
     }
@@ -282,6 +299,7 @@ export class Workbook extends UnitModel<IWorkbookData, UniverInstanceType.UNIVER
 
         this._worksheets.delete(sheetId);
         this._snapshot.sheetOrder.splice(this._snapshot.sheetOrder.indexOf(sheetId), 1);
+        this.ensureSheetOrderUnique();
         this._sheetDisposed$.next(sheetToRemove);
 
         return true;
@@ -446,6 +464,8 @@ export class Workbook extends UnitModel<IWorkbookData, UniverInstanceType.UNIVER
             }
         }
 
+        this.ensureSheetOrderUnique();
+
         // Active the first sheet.
         this.ensureActiveSheet();
     }

packages/sheets/src/commands/mutations/set-worksheet-order.mutation.ts

@@ -44,6 +44,7 @@ export const SetWorksheetOrderMutation: IMutation<ISetWorksheetOrderMutationPara
         const config = workbook.getConfig();
         config.sheetOrder.splice(params.fromOrder, 1);
         config.sheetOrder.splice(params.toOrder, 0, params.subUnitId);
+        workbook.ensureSheetOrderUnique();
         return true;
     },
 };