fix(grid): copy NULL cells as empty fields

apps/desktop/src/lib/__tests__/dataGrid/dataGridCopyExtractor.spec.ts

@@ -3,6 +3,11 @@ import { describe, expect, it } from "vitest";
 import { DEFAULT_DATA_GRID_EXTRACTOR_OPTIONS, normalizeDataGridCopyPreference, normalizeDataGridExtractorOptions, resolveDataGridCopyPreference, validateDataGridExtractorOptions } from "@/lib/dataGrid/dataGridCopyExtractor";
 
 describe("data-grid extractor options", () => {
+  it("defaults DSV NULL output to an empty spreadsheet field", () => {
+    expect(DEFAULT_DATA_GRID_EXTRACTOR_OPTIONS.dsv.nullText).toBe("");
+    expect(normalizeDataGridExtractorOptions({}).dsv.nullText).toBe("");
+  });
+
   it("resolves smart copy to raw for one cell and TSV otherwise", () => {
     expect(normalizeDataGridCopyPreference(undefined)).toBe("smart");
     expect(normalizeDataGridCopyPreference("smart")).toBe("smart");

apps/desktop/src/lib/dataGrid/__tests__/dataGridDetail.spec.ts

@@ -1,5 +1,5 @@
 import { describe, expect, it } from "vitest";
-import { buildDeleteRowConfirmDetails } from "../dataGridDetail";
+import { buildDeleteRowConfirmDetails, dataGridColumnDetailTsv, dataGridRowDetailTsv, type DataGridColumnDetail, type DataGridRowDetail } from "../dataGridDetail";
 
 type TestRow = string[];
 
@@ -131,3 +131,14 @@ describe("buildDeleteRowConfirmDetails", () => {
     expect(result).toBe('Table: people\n{"id":"custom:1","name":"custom:Alice"}');
   });
 });
+
+describe("data grid detail TSV", () => {
+  it("leaves NULL cells empty while preserving literal NULL text", () => {
+    const fields = [{ value: null }, { value: "NULL" }] as unknown as DataGridRowDetail["fields"];
+    const rowDetail = { fields } as DataGridRowDetail;
+    const columnDetail = { fields } as DataGridColumnDetail;
+
+    expect(dataGridRowDetailTsv(rowDetail)).toBe("\tNULL");
+    expect(dataGridColumnDetailTsv(columnDetail)).toBe("\nNULL");
+  });
+});

apps/desktop/src/lib/dataGrid/cellValue.ts

@@ -10,6 +10,10 @@ export function displayCellValue(value: CellValue): string {
   return String(value);
 }
 
+export function clipboardCellValue(value: CellValue): string {
+  return value === null ? "" : displayCellValue(value);
+}
+
 export function firstLineCellDisplayValue(value: string, flatteningMultiLine: boolean): string {
   const lineBreakPattern = /\r\n|\r|\n/g;
   if (flatteningMultiLine) {

apps/desktop/src/lib/dataGrid/dataGridCopyExtractor.ts

@@ -136,7 +136,7 @@ export const DEFAULT_DATA_GRID_EXTRACTOR_OPTIONS: DataGridExtractorOptions = {
   dsv: {
     columnSeparator: ",",
     rowSeparator: "\n",
-    nullText: "NULL",
+    nullText: "",
     quote: '"',
     quotePolicy: "minimal",
     includeColumnHeader: false,

apps/desktop/src/lib/dataGrid/dataGridDetail.ts

@@ -1,5 +1,5 @@
 import { cellImagePreviewUrl } from "@/lib/dataGrid/cellImageUrl";
-import { displayCellValue, type CellValue } from "@/lib/dataGrid/cellValue";
+import { clipboardCellValue, displayCellValue, type CellValue } from "@/lib/dataGrid/cellValue";
 import { formatJsonText } from "@/lib/dataGrid/cellDetailPresentation";
 import type { DatabaseType } from "@/types/database";
 
@@ -215,7 +215,7 @@ export function jsonDetailDisplayValue(value: unknown): unknown {
 }
 
 export function dataGridRowDetailTsv(detail: DataGridRowDetail): string {
-  return detail.fields.map((field) => displayCellValue(field.value)).join("\t");
+  return detail.fields.map((field) => clipboardCellValue(field.value)).join("\t");
 }
 
 export function dataGridColumnDetailJson(detail: DataGridColumnDetail): string {
@@ -230,7 +230,7 @@ export function dataGridColumnDetailJson(detail: DataGridColumnDetail): string {
 }
 
 export function dataGridColumnDetailTsv(detail: DataGridColumnDetail): string {
-  return detail.fields.map((field) => displayCellValue(field.value)).join("\n");
+  return detail.fields.map((field) => clipboardCellValue(field.value)).join("\n");
 }
 
 export interface BuildDeleteRowConfirmDetailsOptions<TRow> {