feat(export): support XLSX comment headers

apps/desktop/src/components/objects/ObjectBrowser.vue

@@ -2012,13 +2012,11 @@ async function exportDataXlsx(row: ObjectBrowserRow) {
 
   try {
     columnInfos = await api.getColumns(props.connection.id, props.database, schema || props.database, row.name, props.catalog);
-    const hasComments = hasXlsxHeaderComments(columnInfos.map((column) => column.comment));
-    const result = await showObjectBrowserXlsxHeaderDialog(hasComments);
+    const result = await showObjectBrowserXlsxHeaderDialog(hasXlsxHeaderComments(columnInfos.map((column) => column.comment)));
     if (result === null) return;
     headerMode = result;
   } catch {
-    // Column fetch failed, fallback to export without comments
-    columnInfos = undefined;
+    // Export still works with field-name headers when column metadata is unavailable.
   }
 
   await exportTableData(row, "xlsx", columnInfos, headerMode);

apps/desktop/src/components/objects/__tests__/ObjectBrowserExport.spec.ts

@@ -0,0 +1,35 @@
+import { readFileSync } from "node:fs";
+import { describe, expect, it } from "vitest";
+
+const source = readFileSync(new URL("../ObjectBrowser.vue", import.meta.url), "utf8");
+
+function functionBody(name: string): string {
+  const signature = new RegExp(`(?:async\\s+)?function\\s+${name}\\s*\\([^)]*\\)\\s*(?::\\s*[^\\{]+)?\\{`, "m").exec(source);
+  if (!signature) throw new Error(`Missing function ${name}`);
+  const bodyStart = signature.index + signature[0].length;
+  let depth = 1;
+  for (let index = bodyStart; index < source.length; index += 1) {
+    if (source[index] === "{") depth += 1;
+    else if (source[index] === "}") depth -= 1;
+    if (depth === 0) return source.slice(bodyStart, index);
+  }
+  throw new Error(`Unclosed function ${name}`);
+}
+
+describe("ObjectBrowser XLSX export", () => {
+  it("asks for a header mode before opening the save dialog when comments exist", () => {
+    const dialog = functionBody("showObjectBrowserXlsxHeaderDialog");
+    const exportDataXlsx = functionBody("exportDataXlsx");
+
+    expect(dialog).toContain('if (!hasComments) return Promise.resolve("name")');
+    expect(exportDataXlsx).toContain("hasXlsxHeaderComments(columnInfos.map((column) => column.comment))");
+    expect(exportDataXlsx.indexOf("await showObjectBrowserXlsxHeaderDialog(")).toBeLessThan(exportDataXlsx.indexOf('await exportTableData(row, "xlsx", columnInfos, headerMode)'));
+  });
+
+  it("falls back to field-name headers when column metadata is unavailable", () => {
+    const exportDataXlsx = functionBody("exportDataXlsx");
+
+    expect(exportDataXlsx).toContain("catch {\n    // Export still works with field-name headers when column metadata is unavailable.\n  }");
+    expect(exportDataXlsx).toContain('await exportTableData(row, "xlsx", columnInfos, headerMode)');
+  });
+});