fix(qa): retry transient Telegram polling failures

extensions/qa-lab/src/live-transports/telegram/telegram-live.runtime.test.ts

@@ -474,6 +474,69 @@ describe("telegram live qa runtime", () => {
     ).toBe(false);
   });
 
+  it("retries transient Telegram polling fetch failures while waiting for scenario replies", async () => {
+    const fetchMock = vi
+      .fn()
+      .mockRejectedValueOnce(new TypeError("fetch failed"))
+      .mockResolvedValueOnce(
+        new Response(
+          JSON.stringify({
+            ok: true,
+            result: [
+              {
+                update_id: 10,
+                message: {
+                  message_id: 99,
+                  chat: { id: -100123 },
+                  from: { id: 88, is_bot: true, username: "sut_bot" },
+                  text: "Identity\nChannel: telegram",
+                  date: 1_700_000_000,
+                  reply_to_message: { message_id: 55 },
+                },
+              },
+            ],
+          }),
+          {
+            status: 200,
+            headers: {
+              "content-type": "application/json",
+            },
+          },
+        ),
+      );
+    vi.stubGlobal("fetch", fetchMock);
+    const observedMessages: Parameters<
+      typeof __testing.waitForObservedMessage
+    >[0]["observedMessages"] = [];
+
+    const result = await __testing.waitForObservedMessage({
+      token: "token",
+      initialOffset: 7,
+      timeoutMs: 5_000,
+      observedMessages,
+      observationScenarioId: "telegram-whoami-command",
+      observationScenarioTitle: "Telegram whoami reply",
+      predicate: (message) =>
+        __testing.matchesTelegramScenarioReply({
+          groupId: "-100123",
+          message,
+          sentMessageId: 55,
+          sutBotId: 88,
+        }),
+    });
+
+    expect(fetchMock).toHaveBeenCalledTimes(2);
+    expect(result.message.messageId).toBe(99);
+    expect(result.nextOffset).toBe(11);
+    expect(observedMessages).toEqual([
+      expect.objectContaining({
+        matchedScenario: true,
+        messageId: 99,
+        scenarioId: "telegram-whoami-command",
+      }),
+    ]);
+  });
+
   it("redacts observed message content by default in artifacts", () => {
     expect(
       __testing.buildObservedMessagesArtifact({

extensions/qa-lab/src/live-transports/telegram/telegram-live.runtime.ts

@@ -595,6 +595,10 @@ async function sendGroupMessage(token: string, groupId: string, text: string) {
   });
 }
 
+async function waitForTelegramPollRetryDelay(remainingMs: number) {
+  await new Promise((resolve) => setTimeout(resolve, Math.min(250, Math.max(100, remainingMs))));
+}
+
 async function waitForObservedMessage(params: {
   token: string;
   initialOffset: number;
@@ -606,6 +610,7 @@ async function waitForObservedMessage(params: {
 }) {
   const startedAt = Date.now();
   let offset = params.initialOffset;
+  let lastPollingError: unknown;
   while (Date.now() - startedAt < params.timeoutMs) {
     const remainingMs = Math.max(
       1_000,
@@ -624,10 +629,13 @@ async function waitForObservedMessage(params: {
         },
         timeoutSeconds * 1000 + 5_000,
       );
+      lastPollingError = undefined;
     } catch (error) {
       if (!isRecoverableTelegramQaPollError(error)) {
         throw error;
       }
+      lastPollingError = error;
+      await waitForTelegramPollRetryDelay(params.timeoutMs - (Date.now() - startedAt));
       continue;
     }
     const batchObservedAtMs = Date.now();
@@ -653,7 +661,13 @@ async function waitForObservedMessage(params: {
       }
     }
   }
-  throw new Error(`timed out after ${params.timeoutMs}ms waiting for Telegram message`);
+  const timeoutMessage = `timed out after ${params.timeoutMs}ms waiting for Telegram message`;
+  if (lastPollingError) {
+    throw new Error(
+      `${timeoutMessage}; last polling error: ${formatErrorMessage(lastPollingError)}`,
+    );
+  }
+  throw new Error(timeoutMessage);
 }
 
 async function waitForTelegramChannelRunning(
@@ -1472,4 +1486,5 @@ export const __testing = {
   shouldLogTelegramQaLiveProgress,
   formatTelegramQaProgressDetails,
   renderTelegramQaMarkdown,
+  waitForObservedMessage,
 };