e2e/telegram-* — live end-to-end test harness for the Telegram bot

True end-to-end coverage: send real messages to a real Telegram chat, poll the bot's reply via the Bot API, and verify what landed.

Why this exists. Unit tests (under app/**/__tests__/) lock in internal module contracts. They don't catch issues that only surface end-to-end: an unbalanced code fence leaking through, a Markdown→HTML translation that looks correct in tests but renders wrong in Telegram, or an agentic reply that truncates when the LLM hits a tool call boundary.

What's in here

e2e/
├── TELEGRAM-README.md   this
├── telegram-cases.ts    catalog of test cases (expand liberally)
├── telegram-api.ts      Telegram Bot API helpers (send, poll, balance check)
└── telegram-run.ts      harness entrypoint — sends prompts, polls replies

Results land under e2e/results/<timestamp>/report.json (shared with the Slack harness).

Approach chosen: (b) MANUAL-TRIGGER smoke with automated upgrade path

The Telegram Bot API does not allow impersonating a human user to send messages. This creates a bootstrapping problem that Slack avoids via its user-token (xoxp-) mechanism:

• A bot can call sendMessage as itself, but the CopilotKit bot's loop guard ignores messages from other bots to prevent infinite loops.
• MTProto-based user automation (TDLib, Telethon) requires a verified Telegram account, a registered API app (api_id + api_hash), a session file, and significant additional infrastructure.

Therefore the default flow is manual-trigger:

1. The harness prints the test prompt.
2. You open the Telegram chat with the bot and send that text.
3. The harness polls getUpdates on the bot token and validates the reply.

Automated upgrade (approach a)

Set TELEGRAM_SENDER_BOT_TOKEN in .env to a second ("sender") bot token. The test chat must be a group or supergroup with both the sender bot and the main bot as members. In this mode the harness posts prompts programmatically via the sender bot and the main bot replies to the group.

Note on coverage: the manual-trigger flow does NOT reduce assertion coverage. All expectations (finalContains, finalNotContains, balancedBrackets, minLength, perReplyChecks) — plus the optional followUp second turn — are evaluated against the real bot reply. What it reduces is automation: you need to type (or paste) each prompt once.

Prerequisites

Finding your TELEGRAM_TEST_CHAT_ID

• DM with the bot: Start a chat with the bot, then call https://api.telegram.org/bot<TOKEN>/getUpdates — the chat.id in your message is your user ID (a positive integer).
• Group: Add the bot to a group, send a message, call getUpdates — the chat.id is a negative integer.

Running

# from examples/slack/

# Copy the example env and fill in the required vars:
cp .env.example .env   # edit TELEGRAM_BOT_TOKEN + TELEGRAM_TEST_CHAT_ID

# Run all cases (manual-trigger mode by default):
pnpm e2e:telegram

# Run a single case by name filter:
CASE_FILTER='C1' pnpm e2e:telegram

In manual-trigger mode the harness will pause before each case and print the prompt to send. You have ~15 seconds to paste it into the Telegram chat before the harness starts polling.

How polling works

For each case the harness:

1. Calls getUpdates to drain any stale messages from the bot's queue.
2. (Automated) Sends the prompt via the sender bot, OR (manual) waits for the operator to send it.
3. Polls getUpdates on the main bot token every sampleIntervalMs until maxWaitMs elapses or the reply stabilises.
4. Runs expectations on the final reply text.
5. Writes results/<timestamp>/report.json.

Streaming via message edits

The example bot uses chunked-edit mode (editMessageText) to stream replies: it posts a _thinking…_ placeholder and then edits it repeatedly as chunks arrive from the LLM. To observe this, the harness subscribes to both message and edited_message update types in getUpdates and tracks the latest text for each bot message_id. This means finalText in expectations reflects the last edit (the completed reply), not the initial placeholder.

Mid-stream samples may still show intermediate edited texts between polls, but the balancedBrackets check is applied only to the final stable text.

Adding cases

Edit telegram-cases.ts. The bar is low — anything you'd want to see working in Telegram belongs in the catalog.