fix: populate topic author in message list

GET /messages always returned the empty placeholder for topic.author
because getMessageRelations handed back a raw topic row that has no
author relation; the messageDTOSchema contract declares a real author
and the route test mocked one, hiding the gap. Fetch the topic author
in getMessageRelations and attach it, so the web message list can show
who owns the topic.

Covered by the new message-relations test, which fails against the
previous implementation.

Author: fengmk2

apps/api/src/lib/message.ts

@@ -100,10 +100,12 @@ export async function getMessageRelations(msg: typeof messages.$inferSelect) {
     msg.topicId ? topicQueries.getById(msg.topicId) : null,
     msg.replyId ? replyQueries.getById(msg.replyId) : null,
   ]);
+  const topicAuthor = topic ? await userQueries.getById(topic.authorId) : null;
+
   return {
     ...msg,
     author,
-    topic,
+    topic: topic ? { ...topic, author: topicAuthor } : null,
     reply,
     isInvalid: !author || !topic,
   };

apps/api/src/routes/message.ts

@@ -75,7 +75,9 @@ message.openapi(listMessagesRoute, async (c) => {
       author: { loginname: author.loginname, avatar_url: author.avatar ?? "" },
       topic: {
         id: String(topic.id),
-        author: { loginname: "", avatar_url: "" },
+        author: topic.author
+          ? { loginname: topic.author.loginname, avatar_url: topic.author.avatar ?? "" }
+          : { loginname: "", avatar_url: "" },
         title: topic.title ?? "",
         last_reply_at: topic.lastReplyAt ? topic.lastReplyAt.toISOString() : null,
       },

apps/api/test/message-relations.test.ts

@@ -0,0 +1,67 @@
+import { beforeEach, describe, expect, it, vi } from "vite-plus/test";
+
+const mocks = vi.hoisted(() => ({
+  userGetById: vi.fn(),
+  topicGetById: vi.fn(),
+  replyGetById: vi.fn(),
+}));
+
+vi.mock("../src/lib/db", () => ({
+  getDb: vi.fn(),
+  userQueries: { getById: mocks.userGetById },
+  topicQueries: { getById: mocks.topicGetById },
+  replyQueries: { getById: mocks.replyGetById },
+}));
+
+vi.mock("../src/lib/mail", () => ({
+  sendAtNotifyMail: vi.fn(),
+  sendReplyNotifyMail: vi.fn(),
+}));
+
+import { getMessageRelations } from "../src/lib/message";
+
+const messageRow = {
+  id: 1,
+  type: "reply",
+  masterId: 10,
+  authorId: 20,
+  topicId: 2,
+  replyId: null,
+  hasRead: false,
+  createAt: new Date("2026-08-05T00:00:00.000Z"),
+};
+
+const actor = { id: 20, loginname: "alice", avatar: "https://example.com/alice.png" };
+const topicAuthor = { id: 30, loginname: "bob", avatar: "https://example.com/bob.png" };
+const topic = { id: 2, title: "话题标题", authorId: 30, lastReplyAt: null };
+
+describe("getMessageRelations", () => {
+  beforeEach(() => {
+    mocks.userGetById.mockReset();
+    mocks.topicGetById.mockReset();
+    mocks.replyGetById.mockReset();
+    mocks.userGetById.mockImplementation(async (id: number) => {
+      if (id === actor.id) return actor;
+      if (id === topicAuthor.id) return topicAuthor;
+      return null;
+    });
+    mocks.topicGetById.mockResolvedValue(topic);
+    mocks.replyGetById.mockResolvedValue(null);
+  });
+
+  it("attaches the topic author so /messages can render it", async () => {
+    const relations = await getMessageRelations(messageRow);
+
+    expect(relations.author).toEqual(actor);
+    expect(relations.topic?.author).toEqual(topicAuthor);
+  });
+
+  it("keeps topic null and flags invalid when the topic is missing", async () => {
+    mocks.topicGetById.mockResolvedValue(null);
+
+    const relations = await getMessageRelations({ ...messageRow, topicId: null });
+
+    expect(relations.topic).toBeNull();
+    expect(relations.isInvalid).toBe(true);
+  });
+});