fix(telegram): render rich header title as plain text

server/lib/drivers/telegram/index.ts

@@ -1,8 +1,15 @@
+import MarkdownIt from "markdown-it";
 import type { RouteTarget, Env, NeutralMessage } from "../../types";
 import type { PlatformDriver, SendResult } from "../types";
 import { sendMessage, sendPhoto, editMessageText, editMessageCaption } from "./rest";
 import { renderNeutralMessage } from "./render";
 
+const markdown = new MarkdownIt({ html: false, linkify: false, breaks: false, typographer: false });
+
+function markdownToText(value: string): string {
+  return markdown.renderInline(value).replace(/<[^>]*>/gu, "");
+}
+
 function smallAvatar(url: string): string {
   const sep = url.includes("?") ? "&" : "?";
   return `${url}${sep}s=64`;
@@ -11,7 +18,7 @@ function smallAvatar(url: string): string {
 function richHeaderUrl(message: NeutralMessage, avatar: string, host: string): string {
   const params = new URLSearchParams();
   if (message.author?.name) params.set("title", message.author.name);
-  if (message.title) params.set("content", message.title);
+  if (message.title) params.set("content", markdownToText(message.title));
   params.set("avatar", avatar);
   return `${host.replace(/\/+$/, "")}/api/richheader?${params.toString()}`;
 }

tests/telegram.test.ts

@@ -191,6 +191,36 @@ describe("telegram-rest sendPhoto", () => {
 });
 
 describe("TelegramDriver", () => {
+  it("uses a plain-text title for the rich header preview", async () => {
+    let capturedInit: RequestInit | undefined;
+    mockFetch((_url, init) => {
+      capturedInit = init;
+      return new Response(JSON.stringify({ ok: true, result: { message_id: 9 } }), { status: 200 });
+    });
+
+    const driver = new TelegramDriver();
+    await driver.send(
+      {
+        title: "OnionSchool/YangYiSongRequest: [CI — running](https://github.com/OnionSchool/YangYiSongRequest/actions)",
+        author: { name: "alice", iconUrl: "https://avatars.githubusercontent.com/u/1" },
+      },
+      { platform: "telegram", chatId: "-100123" },
+      {
+        TELEGRAM_TOKEN: "t",
+        BASE_URL: "https://webhooker.example.com",
+        KV: {} as never,
+        DB: {} as never,
+        GITHUB_WEBHOOK_SECRET: "s",
+      },
+    );
+
+    const body = JSON.parse(String(capturedInit!.body)) as { link_preview_options: { url: string } };
+    const previewUrl = new URL(body.link_preview_options.url);
+    expect(previewUrl.searchParams.get("content")).toBe(
+      "OnionSchool/YangYiSongRequest: CI — running",
+    );
+  });
+
   it("sends a small avatar photo (s=64) when the author has an icon", async () => {
     let capturedInit: RequestInit | undefined;
     mockFetch((url, init) => {