feat: add "Download all" button to bundle attachments into a zip #466

lib/__tests__/download-filename.test.ts

@@ -6,6 +6,7 @@ import type { Email } from '@/lib/jmap/types';
 import {
   emailExportFilename,
   attachmentDownloadFilename,
+  attachmentsBundleFilename,
   bundleExportFilename,
   emailVars,
   attachmentVars,
@@ -93,6 +94,24 @@ describe('bundleExportFilename', () => {
   });
 });
 
+describe('attachmentsBundleFilename', () => {
+  it('embeds the sanitised subject', () => {
+    expect(attachmentsBundleFilename(makeEmail({ subject: 'Invoice March' }))).toBe('attachments_Invoice March.zip');
+  });
+
+  it('sanitises filesystem-reserved characters', () => {
+    expect(attachmentsBundleFilename(makeEmail({ subject: 'Q1/Q2: report' }))).toBe('attachments_Q1_Q2_ report.zip');
+  });
+
+  it('falls back when the subject is empty', () => {
+    expect(attachmentsBundleFilename(makeEmail({ subject: '' }))).toBe('attachments.zip');
+  });
+
+  it('falls back when there is no email', () => {
+    expect(attachmentsBundleFilename(null)).toBe('attachments.zip');
+  });
+});
+
 describe('emailVars (date + address labels)', () => {
   it('returns the invalid-date sentinel for an unparseable date', () => {
     const v = emailVars(makeEmail({ receivedAt: 'not-a-date', sentAt: undefined }));

lib/download-filename.ts

@@ -227,6 +227,15 @@ export function attachmentDownloadFilename(
   return `${transformedStem}.${transformedExt}`;
 }
 
+// Name for a .zip bundling every attachment of a single email, e.g.
+// `attachments_Invoice March.zip`. Falls back to `attachments.zip` when the
+// subject is empty or sanitises away to nothing.
+export function attachmentsBundleFilename(email: Email | null | undefined): string {
+  const subject = email?.subject?.trim();
+  const stem = subject ? sanitizePart(subject, FILENAME_MAX_LEN) : "";
+  return stem ? `attachments_${stem}.zip` : "attachments.zip";
+}
+
 export function bundleVars(count: number, iso?: string): Record<string, string> {
   const dp = dateParts(iso ?? new Date().toISOString());
   return { ...dp, count: String(count) };