From 39efd8af3c9845cfdd2422e713bf495ed0bbb098 Mon Sep 17 00:00:00 2001
From: Linus Rath <139418639+rathlinus@users.noreply.github.com>
Date: Fri, 2 Oct 2026 10:32:22 +0200
Subject: [PATCH] fix: preview the named message when the inbox lookups beside
 it fail #1041

Any failed method in the preview request answered 502, so when the
server named the delivered message and it was read fine, a failing
Inbox query still turned the notification into a generic "New mail".
The named message is now a complete preview on its own.

A response without the optional `total` was also treated as a failure;
it now counts the returned ids.
---
 app/api/push/preview/route.ts            | 24 ++++++++++++---------
 lib/__tests__/push-preview-route.test.ts | 27 +++++++++++++++++++++++-
 2 files changed, 40 insertions(+), 11 deletions(-)

diff --git a/app/api/push/preview/route.ts b/app/api/push/preview/route.ts
index 8be988743..bf19ccdcc 100644
--- a/app/api/push/preview/route.ts
+++ b/app/api/push/preview/route.ts
@@ -247,15 +247,17 @@ export async function GET(request: NextRequest) {
 
     // Missing/failed method responses are preview failures, not proof that
     // there is no unread mail. A non-2xx response lets the SW show its fallback.
-    for (const call of methodCalls as [string, unknown, string][]) {
-      const response = data.methodResponses.find(([method, , callId]) =>
-        method === call[0] && callId === call[2]);
-      const result = response?.[1];
-      if (!result || (call[0] === 'Email/query'
-        ? !Array.isArray(result.ids) || typeof result.total !== 'number'
-        : !Array.isArray(result.list))) {
-        return NextResponse.json({ error: 'JMAP email query failed' }, { status: 502 });
-      }
+    // The message the server named, once read, is a complete preview on its
+    // own, whatever became of the Inbox lookups next to it.
+    const resultOf = (name: string, id: string) =>
+      data.methodResponses.find(([method, , callId]) => method === name && callId === id)?.[1];
+    const failed = (methodCalls as [string, unknown, string][]).some(([name, , id]) => {
+      const result = resultOf(name, id);
+      return !result || (name === 'Email/query' ? !Array.isArray(result.ids) : !Array.isArray(result.list));
+    });
+    const deliveredList = resultOf('Email/get', 'delivered')?.list;
+    if (failed && !(Array.isArray(deliveredList) && deliveredList.length > 0)) {
+      return NextResponse.json({ error: 'JMAP email query failed' }, { status: 502 });
     }
 
     type EmailLite = {
@@ -272,7 +274,9 @@ export async function GET(request: NextRequest) {
     let unreadTotal = 0;
     for (const [method, body, callId] of data.methodResponses) {
       if (method === 'Email/query') {
-        unreadTotal = ((body as { total?: number }).total) ?? 0;
+        // A server that leaves out the optional total still lists the ids.
+        const query = body as { total?: number; ids?: unknown[] };
+        unreadTotal = typeof query.total === 'number' ? query.total : (query.ids?.length ?? 0);
       }
       if (method === 'Email/get') {
         const list = (body as { list?: EmailLite[] }).list ?? [];
diff --git a/lib/__tests__/push-preview-route.test.ts b/lib/__tests__/push-preview-route.test.ts
index fb465f83a..f6d846494 100644
--- a/lib/__tests__/push-preview-route.test.ts
+++ b/lib/__tests__/push-preview-route.test.ts
@@ -137,7 +137,6 @@ describe('push preview JMAP failures', () => {
   it.each([
     [['error', { type: 'serverFail' }, 'eq'], ['error', { type: 'resultReference' }, 'eg']],
     [['Email/query', { ids: ['e1'], total: 1 }, 'eq'], ['error', { type: 'serverFail' }, 'eg']],
-    [['Email/query', { ids: [] }, 'eq'], ['Email/get', { list: [] }, 'eg']],
   ])('does not report zero unread on an email method failure', async (query, get) => {
     fetchJmapServer.mockReset()
       .mockResolvedValueOnce(jsonResponse(SESSION))
@@ -156,6 +155,32 @@ describe('push preview JMAP failures', () => {
       ] }));
     expect(await callRoute('a')).toEqual({ status: 200, body: { email: null, unreadTotal: 0, slot: 0 } });
   });
+
+  // `total` is optional in a JMAP Email/query response.
+  it('counts the ids when the server leaves out the total', async () => {
+    fetchJmapServer.mockReset()
+      .mockResolvedValueOnce(jsonResponse(SESSION))
+      .mockResolvedValueOnce(jsonResponse({ methodResponses: [['Mailbox/query', { ids: ['inbox'] }, 'mb']] }))
+      .mockResolvedValueOnce(jsonResponse({ methodResponses: [
+        ['Email/query', { ids: [] }, 'eq'],
+        ['Email/get', { list: [] }, 'eg'],
+      ] }));
+    expect(await callRoute('a')).toEqual({ status: 200, body: { email: null, unreadTotal: 0, slot: 0 } });
+  });
+
+  it('previews the named message even when the Inbox lookups fail', async () => {
+    fetchJmapServer.mockReset()
+      .mockResolvedValueOnce(jsonResponse(SESSION))
+      .mockResolvedValueOnce(jsonResponse({ methodResponses: [['Mailbox/query', { ids: ['inbox'] }, 'mb']] }))
+      .mockResolvedValueOnce(jsonResponse({ methodResponses: [
+        ['error', { type: 'serverFail' }, 'eq'],
+        ['error', { type: 'resultReference' }, 'eg'],
+        ['Email/get', { list: [{ id: 'd', threadId: 'td' }] }, 'delivered'],
+      ] }));
+    expect(await callRoute('a', 'd')).toEqual({
+      status: 200, body: { email: { id: 'd', threadId: 'td' }, unreadTotal: 1, slot: 0 },
+    });
+  });
 });