Merge pull request #1213 from shukiv/fix/draft-body-from-body-parts

fix: take a re-opened draft's body from its body parts only

components/mail/mail-app.tsx

@@ -85,6 +85,7 @@ import { MvTopBar } from "@/components/layout/mv-top-bar";
 import { MvListToolbar } from "@/components/email/mv-list-toolbar";
 import { SidebarAppsModal } from "@/components/layout/sidebar-apps-modal";
 import { InlineAppView } from "@/components/layout/inline-app-view";
+import { getDraftTextBody } from '@/lib/email-body-selection';
 import { useSidebarApps } from "@/hooks/use-sidebar-apps";
 import { useIdentitySync } from "@/hooks/use-identity-sync";
 import { useIsEmbedded } from "@/hooks/use-is-embedded";
@@ -2087,9 +2088,9 @@ export function MailApp({ linkSegments: routeSegments }: MailAppProps = {}) {
 
     draft = await emailHooks.onBeforeEditDraft.transform(draft);
 
-    const bodyText = draft.bodyValues
-      ? Object.values(draft.bodyValues).map(v => v.value).join('\n')
-      : '';
+    // Only the parts the server lists as the body: bodyValues also carries
+    // every text/* ATTACHMENT, which used to be joined in as the message.
+    const bodyText = getDraftTextBody(draft);
     // A plain-text-only draft lists its text/plain part under htmlBody
     // (RFC 8621 § 4.1.4 fallback) - only treat it as HTML when it really is.
     const draftHtmlPart = draft.htmlBody?.[0];

components/pro/pro-email-tab-body.tsx

@@ -19,6 +19,7 @@ import { getQuoteBodies } from "@/lib/email-composer-utils";
 import { buildForwardAsAttachmentPayload } from "@/lib/forward-as-attachment";
 import { KEYWORD_PREFIX, KEYWORD_PREFIX_LEGACY } from "@/lib/thread-utils";
 import { cn } from "@/lib/utils";
+import { getDraftTextBody } from '@/lib/email-body-selection';
 
 interface ProEmailTabBodyProps {
   tabId: string;
@@ -319,9 +320,9 @@ export function ProEmailView({ emailId, client: clientOverride, accountId, onLoa
   const handleEditDraft = useCallback(() => {
     if (!email) return;
 
-    const bodyText = email.bodyValues
-      ? Object.values(email.bodyValues).map((v) => v.value).join('\n')
-      : '';
+    // Only the parts the server lists as the body: bodyValues also carries
+    // every text/* ATTACHMENT, which used to be joined in as the message.
+    const bodyText = getDraftTextBody(email);
     // A plain-text-only draft lists its text/plain part under htmlBody
     // (RFC 8621 § 4.1.4 fallback) - only treat it as HTML when it really is.
     const draftHtmlPart = email.htmlBody?.[0];

lib/__tests__/email-body-selection.test.ts

@@ -1,5 +1,5 @@
 import { describe, it, expect } from 'vitest';
-import { getRenderableHtmlBody } from '@/lib/email-body-selection';
+import { getRenderableHtmlBody, getDraftTextBody } from '@/lib/email-body-selection';
 
 type PartialEmail = Parameters<typeof getRenderableHtmlBody>[0];
 
@@ -105,3 +105,45 @@ describe('getRenderableHtmlBody', () => {
     expect(getRenderableHtmlBody(email)).toBeNull();
   });
 });
+
+/**
+ * Re-opening a draft used to join every value in bodyValues into the
+ * message. getEmail asks for fetchAllBodyValues, which per RFC 8621
+ * covers every text/* part including attachments, so a draft carrying
+ * only a .csv re-opened with the contents of that .csv as its text - and
+ * the next save made that the real message.
+ */
+describe('getDraftTextBody', () => {
+  type DraftEmail = Parameters<typeof getDraftTextBody>[0];
+
+  const draft = (textBody: { partId: string }[], values: Record<string, string>): DraftEmail => ({
+    textBody: textBody as DraftEmail['textBody'],
+    bodyValues: Object.fromEntries(
+      Object.entries(values).map(([id, value]) => [id, { value, isEncodingProblem: false, isTruncated: false }]),
+    ) as DraftEmail['bodyValues'],
+  });
+
+  it('takes the body from the parts listed as the body', () => {
+    expect(getDraftTextBody(draft([{ partId: '1' }], { '1': 'hello' }))).toBe('hello');
+  });
+
+  it('ignores a text attachment that is not part of the body', () => {
+    // Part 2 is an attached text/csv: fetchAllBodyValues returns its value
+    // too, but it is not in textBody and is not the message.
+    const d = draft([{ partId: '1' }], { '1': 'see attached', '2': 'Date,Amount\n2026-08-30,12.00' });
+    expect(getDraftTextBody(d)).toBe('see attached');
+  });
+
+  it('is empty for a draft that has attachments and no body at all', () => {
+    expect(getDraftTextBody(draft([], { '2': 'Date,Amount\n2026-08-30,12.00' }))).toBe('');
+  });
+
+  it('joins several body parts', () => {
+    expect(getDraftTextBody(draft([{ partId: '1' }, { partId: '2' }], { '1': 'one', '2': 'two' })))
+      .toBe('one\ntwo');
+  });
+
+  it('survives a part whose value the server did not return', () => {
+    expect(getDraftTextBody(draft([{ partId: '1' }, { partId: '9' }], { '1': 'one' }))).toBe('one');
+  });
+});

lib/email-body-selection.ts

@@ -33,3 +33,24 @@ export function getRenderableHtmlBody(
 
   return htmlContent;
 }
+
+/**
+ * The plain-text body of a draft being re-opened, taken from the parts the
+ * server lists as the body and from nothing else.
+ *
+ * `bodyValues` is keyed by part id, and `getEmail` asks for
+ * `fetchAllBodyValues`, which per RFC 8621 § 4.1.4 covers every `text/*`
+ * part of the message - attachments included. Joining all of them put the
+ * contents of an attached .csv or .txt into the composer as the message
+ * text: a draft carrying only attachments and no body re-opened showing an
+ * attachment's contents as what you had written, and saving or sending it
+ * then made that the actual message.
+ */
+export function getDraftTextBody(
+  email: Pick<Email, 'textBody' | 'bodyValues'>
+): string {
+  return (email.textBody ?? [])
+    .map(part => (part.partId ? email.bodyValues?.[part.partId]?.value : undefined))
+    .filter((value): value is string => !!value)
+    .join('\n');
+}