feat(telegram): render markdown and send author avatar photo

src/__tests__/telegram.test.ts

@@ -1,6 +1,7 @@
 import { describe, it, expect, afterEach } from "bun:test";
-import { sendMessage } from "../drivers/telegram/rest";
+import { sendMessage, sendPhoto } from "../drivers/telegram/rest";
 import { renderNeutralMessage } from "../drivers/telegram/render";
+import { TelegramDriver } from "../drivers/telegram";
 import type { NeutralMessage } from "../types";
 
 function mockFetch(handler: (url: string, init?: RequestInit) => Response): void {
@@ -38,6 +39,25 @@ describe("telegram renderNeutralMessage", () => {
     expect(out).not.toContain("<b>acme");
     expect(out).toContain("&lt;script&gt;alert(1)&lt;/script&gt;");
   });
+
+  it("converts Discord markdown to Telegram HTML", () => {
+    const out = renderNeutralMessage({
+      title: "acme/widget#7: Add feature",
+      description: "**1** commit pushed to `main`\n[View comparison](https://github.com/acme/widget/compare/a...b)",
+      fields: [{ name: "Status", value: "**ok** and `done`" }],
+    });
+    expect(out).toContain("<b>1</b> commit pushed to <code>main</code>");
+    expect(out).toContain('<a href="https://github.com/acme/widget/compare/a...b">View comparison</a>');
+    expect(out).toContain("<b>Status</b>: <b>ok</b> and <code>done</code>");
+  });
+
+  it("formats ISO timestamps into a readable UTC string", () => {
+    const out = renderNeutralMessage({
+      title: "acme/widget: t",
+      timestamp: "2026-08-02T21:26:04.042Z",
+    });
+    expect(out).toContain("<i>2026-08-02 21:26 UTC</i>");
+  });
 });
 
 describe("telegram-rest sendMessage", () => {
@@ -93,3 +113,70 @@ describe("telegram-rest sendMessage", () => {
     expect(result.errorCode).toBe("NO_TOKEN");
   });
 });
+
+describe("telegram-rest sendPhoto", () => {
+  it("posts to the bot API with photo, caption and thread id", async () => {
+    let capturedUrl = "";
+    let capturedInit: RequestInit | undefined;
+    mockFetch((url, init) => {
+      capturedUrl = url;
+      capturedInit = init;
+      return new Response(JSON.stringify({ ok: true, result: { message_id: 7 } }), {
+        status: 200,
+      });
+    });
+
+    const result = await sendPhoto("t", "-100123", "https://avatars/1.png", "caption here", "999");
+
+    expect(result.ok).toBe(true);
+    expect(result.messageId).toBe("7");
+    expect(capturedUrl).toBe("https://api.telegram.org/bott/sendPhoto");
+    const body = JSON.parse(String(capturedInit!.body)) as Record<string, unknown>;
+    expect(body.chat_id).toBe("-100123");
+    expect(body.photo).toBe("https://avatars/1.png");
+    expect(body.caption).toBe("caption here");
+    expect(body.message_thread_id).toBe(999);
+  });
+});
+
+describe("TelegramDriver", () => {
+  it("sends a small avatar photo (s=64) when the author has an icon", 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();
+    const result = await driver.send(
+      {
+        title: "acme/widget: Add feature",
+        author: { name: "alice", iconUrl: "https://avatars.githubusercontent.com/u/1?v=4" },
+      },
+      { platform: "telegram", chatId: "-100123" },
+      { TELEGRAM_TOKEN: "t", KV: {} as never, DB: {} as never, GITHUB_WEBHOOK_SECRET: "s" },
+    );
+
+    expect(result.ok).toBe(true);
+    const body = JSON.parse(String(capturedInit!.body)) as Record<string, unknown>;
+    expect(body.photo).toBe("https://avatars.githubusercontent.com/u/1?v=4&s=64");
+  });
+
+  it("sends a plain message when the author has no icon", async () => {
+    let capturedUrl = "";
+    mockFetch((url) => {
+      capturedUrl = url;
+      return new Response(JSON.stringify({ ok: true, result: { message_id: 10 } }), { status: 200 });
+    });
+
+    const driver = new TelegramDriver();
+    const result = await driver.send(
+      { title: "acme/widget: Add feature" },
+      { platform: "telegram", chatId: "-100123" },
+      { TELEGRAM_TOKEN: "t", KV: {} as never, DB: {} as never, GITHUB_WEBHOOK_SECRET: "s" },
+    );
+
+    expect(result.ok).toBe(true);
+    expect(capturedUrl).toContain("/sendMessage");
+  });
+});

src/drivers/telegram/index.ts

@@ -1,8 +1,13 @@
 import type { RouteTarget, Env, NeutralMessage } from "../../types";
 import type { PlatformDriver, SendResult } from "../types";
-import { sendMessage } from "./rest";
+import { sendMessage, sendPhoto } from "./rest";
 import { renderNeutralMessage } from "./render";
 
+function smallAvatar(url: string): string {
+  const sep = url.includes("?") ? "&" : "?";
+  return `${url}${sep}s=64`;
+}
+
 export class TelegramDriver implements PlatformDriver {
   readonly id = "telegram";
 
@@ -12,6 +17,11 @@ export class TelegramDriver implements PlatformDriver {
       return { ok: false, error: "target.chatId is required", errorCode: "NO_TARGET" };
     }
     const token = env.TELEGRAM_TOKEN ?? "";
-    return sendMessage(token, chatId, renderNeutralMessage(message), target.topicId);
+    const text = renderNeutralMessage(message);
+    const avatar = message.author?.iconUrl;
+    if (avatar) {
+      return sendPhoto(token, chatId, smallAvatar(avatar), text, target.topicId);
+    }
+    return sendMessage(token, chatId, text, target.topicId);
   }
 }

src/drivers/telegram/render.ts

@@ -8,35 +8,50 @@ function esc(s: string): string {
     .replace(/"/g, """);
 }
 
-function inlineUrl(url?: string, text?: string): string {
-  const label = esc(text ?? url ?? "");
-  if (!url) return label;
-  return `<a href="${esc(url)}">${label}</a>`;
+function mdToHtml(s: string): string {
+  let out = esc(s);
+  out = out.replace(/\[([^\]]+)\]\(([^)]+)\)/g, (_m, label, url) => `<a href="${esc(url)}">${label}</a>`);
+  out = out.replace(/\*\*([^*]+)\*\*/g, "<b>$1</b>");
+  out = out.replace(/`([^`]+)`/g, "<code>$1</code>");
+  out = out.replace(/(^|[^*])\*([^*]+)\*/g, "$1<i>$2</i>");
+  out = out.replace(/~~([^~]+)~~/g, "<s>$1</s>");
+  return out;
+}
+
+function formatTimestamp(ts?: string): string {
+  if (!ts) return "";
+  const d = new Date(ts);
+  if (Number.isNaN(d.getTime())) return ts;
+  const pad = (n: number): string => String(n).padStart(2, "0");
+  return `${d.getUTCFullYear()}-${pad(d.getUTCMonth() + 1)}-${pad(d.getUTCDate())} ${pad(d.getUTCHours())}:${pad(d.getUTCMinutes())} UTC`;
 }
 
 export function renderNeutralMessage(message: NeutralMessage): string {
   const parts: string[] = [];
-  const title = inlineUrl(message.url, message.title);
+
+  const title = message.url
+    ? `<a href="${esc(message.url)}">${mdToHtml(message.title)}</a>`
+    : mdToHtml(message.title);
   parts.push(`<b>${title}</b>`);
 
   if (message.author) {
-    const author = message.author.url
-      ? `<a href="${esc(message.author.url)}">${esc(message.author.name)}</a>`
-      : esc(message.author.name);
+    const name = mdToHtml(message.author.name);
+    const author = message.author.url ? `<a href="${esc(message.author.url)}">${name}</a>` : name;
     parts.push(`👤 ${author}`);
   }
 
   if (message.description) {
-    parts.push(esc(message.description));
+    parts.push(mdToHtml(message.description));
   }
 
   for (const field of message.fields ?? []) {
-    parts.push(`<b>${esc(field.name)}</b>: ${esc(field.value)}`);
+    parts.push(`<b>${mdToHtml(field.name)}</b>: ${mdToHtml(field.value)}`);
   }
 
   const meta: string[] = [];
   if (message.footer) meta.push(esc(message.footer));
-  if (message.timestamp) meta.push(esc(message.timestamp));
+  const ts = formatTimestamp(message.timestamp);
+  if (ts) meta.push(ts);
   if (meta.length > 0) {
     parts.push(`<i>${meta.join(" · ")}</i>`);
   }

src/drivers/telegram/rest.ts

@@ -9,27 +9,13 @@ interface TelegramResponse {
   result?: { message_id?: number };
 }
 
-export async function sendMessage(
+async function post(
   token: string,
+  method: string,
+  body: Record<string, unknown>,
   chatId: string,
-  text: string,
-  topicId?: string,
 ): Promise<SendResult> {
-  if (!token) {
-    return { ok: false, error: "TELEGRAM_TOKEN not configured", errorCode: "NO_TOKEN" };
-  }
-
-  const body: Record<string, unknown> = {
-    chat_id: chatId,
-    text,
-    parse_mode: "HTML",
-    disable_web_page_preview: true,
-  };
-  if (topicId) {
-    body.message_thread_id = Number(topicId);
-  }
-
-  const url = `${TELEGRAM_API}/bot${token}/sendMessage`;
+  const url = `${TELEGRAM_API}/bot${token}/${method}`;
   let lastStatus = 0;
   let lastError = "";
 
@@ -95,3 +81,48 @@ export async function sendMessage(
     attempts: 3,
   };
 }
+
+export async function sendMessage(
+  token: string,
+  chatId: string,
+  text: string,
+  topicId?: string,
+): Promise<SendResult> {
+  if (!token) {
+    return { ok: false, error: "TELEGRAM_TOKEN not configured", errorCode: "NO_TOKEN" };
+  }
+  const body: Record<string, unknown> = {
+    chat_id: chatId,
+    text,
+    parse_mode: "HTML",
+    disable_web_page_preview: true,
+  };
+  if (topicId) {
+    body.message_thread_id = Number(topicId);
+  }
+  return post(token, "sendMessage", body, chatId);
+}
+
+export async function sendPhoto(
+  token: string,
+  chatId: string,
+  photoUrl: string,
+  caption?: string,
+  topicId?: string,
+): Promise<SendResult> {
+  if (!token) {
+    return { ok: false, error: "TELEGRAM_TOKEN not configured", errorCode: "NO_TOKEN" };
+  }
+  const body: Record<string, unknown> = {
+    chat_id: chatId,
+    photo: photoUrl,
+    parse_mode: "HTML",
+  };
+  if (caption) {
+    body.caption = caption;
+  }
+  if (topicId) {
+    body.message_thread_id = Number(topicId);
+  }
+  return post(token, "sendPhoto", body, chatId);
+}