[FIX] xlsx: preserve leading whitespace at export

If a shared string has leading/trailing whitespace, it should have the
attribute `xml:space="preserve"` otherwise the whitespace is trimmed
in Excel.

closes #5377

Task: 4044862
Signed-off-by: Rémi Rahir (rar) <[email protected]>
Signed-off-by: Adrien Minne (adrm) <[email protected]>

src/xlsx/xlsx_writer.ts

@@ -283,7 +283,12 @@ function createSharedStrings(strings: string[]): XLSXExportFile {
     ["uniqueCount", strings.length],
   ];
 
-  const stringNodes = strings.map((string) => escapeXml/*xml*/ `<si><t>${string}</t></si>`);
+  const stringNodes = strings.map((string) => {
+    if (string.trim() !== string) {
+      return escapeXml/*xml*/ `<si><t xml:space="preserve">${string}</t></si>`;
+    }
+    return escapeXml/*xml*/ `<si><t>${string}</t></si>`;
+  });
 
   const xml = escapeXml/*xml*/ `
     <sst ${formatAttributes(namespaces)}>

tests/xlsx/xlsx_export.test.ts

@@ -765,6 +765,20 @@ describe("Test XLSX export", () => {
     expect(styles[1].querySelector("alignment")!.getAttribute("wrapText")).toBe("1");
   });
 
+  test("Leading and trailing whitespace in strings are preserved", async () => {
+    const model = new Model();
+    setCellContent(model, "A1", "    Multiline with\n   leading and trailing spaces\n    ");
+
+    const exportedXlsx = await exportPrettifiedXlsx(model);
+    const sharedStrings = parseXML(
+      exportedXlsx.files.find((f) => f["contentType"] === "sharedStrings")!["content"]
+    );
+
+    const string = sharedStrings.querySelector("si t")!;
+    expect(string.getAttribute("xml:space")).toBe("preserve");
+    expect(string.textContent).toBe("    Multiline with\n   leading and trailing spaces\n    ");
+  });
+
   describe("formulas", () => {
     beforeAll(() => {
       functionRegistry.add("NOW", {