Preserve QExcell frozen panes in XLSX

src/io/excellOffice.test.ts

@@ -5,6 +5,7 @@ import {
   buildCellXml,
   buildHyperlinksXml,
   buildMergeCellsXml,
+  buildSheetViewsXml,
   createCellStyleRegistry,
   buildWorksheetRelationshipsXml,
   buildWorksheetXml,
@@ -17,6 +18,7 @@ import {
   workbookSheetRefs,
   worksheetXmlToCells,
   worksheetXmlToCellFormats,
+  worksheetXmlToFrozenPane,
   worksheetXmlToHyperlinks,
   worksheetXmlToMergedCells,
   xlsxStylesXmlToCellFormatTable,
@@ -587,6 +589,60 @@ describe("excellOffice OOXML helpers", () => {
     expect(imported.sheets[2]).toMatchObject({ id: "sheet-3", name: "Служебный", visibility: "veryHidden" });
   });
 
+  it("читает и записывает закрепленные области XLSX через sheetViews pane", async () => {
+    expect(
+      worksheetXmlToFrozenPane({
+        worksheet: {
+          sheetViews: {
+            sheetView: {
+              pane: { xSplit: "1", ySplit: "2", topLeftCell: "B3", activePane: "bottomRight", state: "frozen" }
+            }
+          }
+        }
+      })
+    ).toEqual({ columns: 1, rows: 2, topLeftCell: "B3", activePane: "bottomRight" });
+
+    expect(
+      worksheetXmlToFrozenPane({
+        worksheet: {
+          sheetViews: {
+            sheetView: {
+              pane: { xSplit: "1", state: "split" }
+            }
+          }
+        }
+      })
+    ).toBeUndefined();
+
+    expect(buildSheetViewsXml({ columns: 1, rows: 1 })).toBe(
+      '<sheetViews><sheetView workbookViewId="0"><pane xSplit="1" ySplit="1" topLeftCell="B2" activePane="bottomRight" state="frozen"/></sheetView></sheetViews>'
+    );
+
+    const blob = await exportXlsxBlob({
+      id: "book-1",
+      title: "Frozen panes.xlsx",
+      updatedAt: "2026-06-01T00:00:00.000Z",
+      activeSheet: "sheet-1",
+      sheets: [
+        {
+          id: "sheet-1",
+          name: "Freeze",
+          frozenPane: { columns: 1, rows: 1 },
+          cells: { A1: "Header", B2: "Body" }
+        }
+      ]
+    });
+    const zip = await JSZip.loadAsync(await blob.arrayBuffer());
+    const sheetXml = (await zip.file("xl/worksheets/sheet1.xml")?.async("string")) ?? "";
+    const imported = await importXlsxFile(new File([blob], "Frozen panes.xlsx", { type: blob.type }));
+
+    expect(sheetXml).toContain(
+      '<sheetViews><sheetView workbookViewId="0"><pane xSplit="1" ySplit="1" topLeftCell="B2" activePane="bottomRight" state="frozen"/></sheetView></sheetViews>'
+    );
+    expect(sheetXml.indexOf("<sheetViews>")).toBeLessThan(sheetXml.indexOf("<sheetData>"));
+    expect(imported.sheets[0].frozenPane).toEqual({ columns: 1, rows: 1, topLeftCell: "B2", activePane: "bottomRight" });
+  });
+
   it("создает OOXML chart part для диаграммы XLSX", () => {
     const xml = buildChartXml(
       {