feat(import): auto-map headerless data by target order

apps/desktop/src/components/import/TableImportDialog.vue

@@ -523,7 +523,8 @@ function applyAutoMapping() {
     columnMapping.value = Object.fromEntries(currentPreview.columns.map((source) => [source, source]));
     return;
   }
-  columnMapping.value = autoMapImportColumns(currentPreview.columns, targetColumnNames.value);
+  const headerless = titleRow.value === 0 && (isDelimitedFormat(sourceFormat.value) || sourceFormat.value === "excel");
+  columnMapping.value = autoMapImportColumns(currentPreview.columns, targetColumnNames.value, headerless ? "position" : "name");
 }
 
 function applySuggestedColumnDataTypes(currentPreview = preview.value) {

apps/desktop/src/components/import/__tests__/TableImportDialog.existingTarget.spec.ts

@@ -202,12 +202,12 @@ async function mountDialog(
   await flushAsyncUpdates();
 }
 
-async function selectWorkbook() {
+async function selectWorkbook(fileName = "rows.xlsx") {
   const fileInput = document.body.querySelector<HTMLInputElement>('input[type="file"]');
   expect(fileInput).toBeTruthy();
   Object.defineProperty(fileInput, "files", {
     configurable: true,
-    value: [new File(["test workbook"], "rows.xlsx", { type: "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" })],
+    value: [new File(["test workbook"], fileName)],
   });
   fileInput?.dispatchEvent(new Event("change", { bubbles: true }));
   await flushAsyncUpdates();
@@ -258,6 +258,45 @@ afterEach(() => {
 });
 
 describe("TableImportDialog existing targets", () => {
+  it.each(["rows.csv", "rows.tsv", "rows.txt", "rows.xlsx"])("maps headerless %s by ordinal position and imports a manual adjustment", async (fileName) => {
+    i18n.global.locale.value = "en";
+    await mountDialog({ prefillTable: "existing_target" });
+    await selectWorkbook(fileName);
+
+    mocks.previewTableImportFile.mockResolvedValueOnce({
+      fileName,
+      filePath: `/tmp/${fileName}`,
+      fileType: fileName.endsWith("xlsx") ? "excel" : "csv",
+      sizeBytes: 24,
+      columns: ["column_1", "column_2", "column_3"],
+      rows: [[1, "Alice", "extra"]],
+      totalRows: 1,
+      sourceFingerprint: "headerless",
+    });
+    const titleInput = [...document.body.querySelectorAll<HTMLInputElement>('input[type="number"]')].find((input) => input.parentElement?.textContent?.includes("Title row"));
+    expect(titleInput).toBeTruthy();
+    titleInput!.value = "0";
+    titleInput!.dispatchEvent(new Event("input", { bubbles: true }));
+    await vi.waitFor(() => expect(mocks.previewTableImportFile.mock.calls.at(-1)?.[1]).toMatchObject({ parseOptions: { titleRow: 0 } }));
+    await flushAsyncUpdates();
+    buttonContaining("Next")?.click();
+    await flushAsyncUpdates();
+    const mappings = [...document.body.querySelectorAll<HTMLSelectElement>("select")];
+    expect(mappings.map((select) => select.value)).toEqual(["id", "name", "__skip__"]);
+
+    mappings[1]!.value = "__skip__";
+    mappings[1]!.dispatchEvent(new Event("change", { bubbles: true }));
+    await flushAsyncUpdates();
+    buttonContaining("Next")?.click();
+    await flushAsyncUpdates();
+    buttonContaining("Next")?.click();
+    await flushAsyncUpdates();
+    buttonContaining("Start Import")?.click();
+    await flushAsyncUpdates();
+    expect(mocks.importTableFile).toHaveBeenCalledTimes(1);
+    expect(mocks.importTableFile.mock.calls[0]![0]).toMatchObject({ parseOptions: { titleRow: 0 }, mappings: [{ sourceColumn: "column_1", targetColumn: "id" }] });
+  });
+
   it("lets a database-level import choose an existing table and loads its columns", async () => {
     i18n.global.locale.value = "en";
     await mountDialog();

apps/desktop/src/lib/__tests__/table/tableImport.spec.ts

@@ -95,6 +95,16 @@ describe("tableImport", () => {
     });
   });
 
+  it("maps headerless columns by position even when generated names match a different target", () => {
+    expect(autoMapImportColumns(["column_1", "column_2"], ["column_2", "column_1"], "position")).toEqual({ column_1: "column_2", column_2: "column_1" });
+  });
+
+  it("skips excess source columns and leaves excess target columns unmapped", () => {
+    expect(autoMapImportColumns(["column_1", "column_2", "column_3"], ["id", "name"], "position")).toEqual({ column_1: "id", column_2: "name", column_3: "" });
+    expect(autoMapImportColumns(["column_1"], ["id", "name"], "position")).toEqual({ column_1: "id" });
+    expect(autoMapImportColumns(["column_1"], [], "position")).toEqual({ column_1: "" });
+  });
+
   it("rejects empty mappings and duplicate target columns", () => {
     expect(validateImportMappings([])).toEqual({
       valid: false,

apps/desktop/src/lib/table/tableImport.ts

@@ -136,7 +136,10 @@ export function normalizeImportColumnName(name: string): string {
   return name.trim().toLowerCase().replace(/[_-]+/g, " ").replace(/\s+/g, " ");
 }
 
-export function autoMapImportColumns(sourceColumns: string[], targetColumns: string[]): Record<string, string> {
+export function autoMapImportColumns(sourceColumns: string[], targetColumns: string[], mode: "name" | "position" = "name"): Record<string, string> {
+  if (mode === "position") {
+    return Object.fromEntries(sourceColumns.map((source, index) => [source, targetColumns[index] ?? IMPORT_SKIP_TARGET]));
+  }
   const exactTargets = new Map(targetColumns.map((column) => [column, column]));
   const normalizedTargets = new Map(targetColumns.map((column) => [normalizeImportColumnName(column), column]));