test(bot): add regression test for init retry behavior

app/bot/webhook.ensureBotInit.test.ts

@@ -0,0 +1,83 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { Bot } from 'grammy';
+
+test('ensureBotInit resets after init failure (no stuck rejected promise)', async (t) => {
+  const originalInit = Bot.prototype.init;
+  const originalHandleUpdate = Bot.prototype.handleUpdate;
+
+  let initCalls = 0;
+  let handleUpdateCalls = 0;
+
+  Bot.prototype.init = async function initMock(): Promise<void> {
+    initCalls += 1;
+    if (initCalls === 1) throw new Error('init failed (simulated)');
+  };
+
+  Bot.prototype.handleUpdate = async function handleUpdateMock(): Promise<void> {
+    handleUpdateCalls += 1;
+  };
+
+  t.after(() => {
+    Bot.prototype.init = originalInit;
+    Bot.prototype.handleUpdate = originalHandleUpdate;
+    delete process.env.BOT_TOKEN;
+    delete process.env.TELEGRAM_BOT_TOKEN;
+  });
+
+  process.env.BOT_TOKEN = 'test-token';
+
+  // Import after env + prototype mocks so the module creates a bot using the patched methods.
+  const mod = await import('./webhook.ts');
+  const handler = mod.default as (
+    req: { method: string; body?: unknown },
+    res: {
+      setHeader(name: string, value: string): void;
+      status(code: number): { json(data: unknown): void; end(): void };
+      end(): void;
+    },
+  ) => Promise<void>;
+
+  function createRes() {
+    let statusCode: number | null = null;
+    let jsonBody: unknown = undefined;
+    return {
+      get statusCode() {
+        return statusCode;
+      },
+      get jsonBody() {
+        return jsonBody;
+      },
+      res: {
+        setHeader() {},
+        status(code: number) {
+          statusCode = code;
+          return {
+            json(data: unknown) {
+              jsonBody = data;
+            },
+            end() {},
+          };
+        },
+        end() {},
+      },
+    };
+  }
+
+  const update = JSON.stringify({
+    update_id: 1,
+    message: { chat: { id: 123 }, text: 'hi' },
+  });
+
+  const first = createRes();
+  await handler({ method: 'POST', body: update }, first.res);
+  assert.equal(first.statusCode, 500);
+
+  const second = createRes();
+  await handler({ method: 'POST', body: update }, second.res);
+  assert.equal(second.statusCode, 200);
+
+  assert.equal(initCalls, 2);
+  assert.equal(handleUpdateCalls, 1);
+});
+