lettabot/TESTING.md

Testing Guide

LettaBot uses Vitest for testing with two test suites: unit tests and end-to-end (E2E) tests.

Quick Start

# Run unit tests (watch mode)
npm test

# Run unit tests once (CI mode)
npm run test:run

# Run E2E tests (requires env vars)
npm run test:e2e

Unit Tests

Unit tests are co-located with source files using the .test.ts suffix.

Structure

src/
  core/
    commands.ts
    commands.test.ts      # Tests for commands.ts
    formatter.ts
    formatter.test.ts     # Tests for formatter.ts
  utils/
    phone.ts
    phone.test.ts

Writing Unit Tests

import { describe, it, expect } from 'vitest';
import { myFunction } from './my-module.js';

describe('myFunction', () => {
  it('does something expected', () => {
    expect(myFunction('input')).toBe('output');
  });

  it('handles edge cases', () => {
    expect(myFunction(null)).toBeNull();
  });
});

What to Test

• Utility functions - Pure functions are easy to test
• Parsing logic - Config parsing, message formatting
• Business rules - Access control, rate limiting, etc.

E2E Tests

E2E tests verify the full message flow against a real Letta Cloud agent.

Setup

E2E tests require two environment variables:

export LETTA_API_KEY=your-api-key
export LETTA_E2E_AGENT_ID=agent-xxx

Without these, E2E tests are automatically skipped.

Test Agent

We use a dedicated test agent named "greg" on Letta Cloud. This agent:

• Has minimal configuration
• Is only used for automated testing
• Should not have any sensitive data

E2E Test Structure

e2e/
  bot.e2e.test.ts    # Main E2E test file

MockChannelAdapter

The MockChannelAdapter (in src/test/mock-channel.ts) simulates a messaging channel:

import { MockChannelAdapter } from '../src/test/mock-channel.js';

const adapter = new MockChannelAdapter();
bot.registerChannel(adapter);

// Simulate a message and wait for response
const response = await adapter.simulateMessage('Hello!');
expect(response).toBeTruthy();

// Check sent messages
const sent = adapter.getSentMessages();
expect(sent).toHaveLength(1);

E2E Test Example

import { describe, it, expect, beforeAll } from 'vitest';
import { LettaBot } from '../src/core/bot.js';
import { MockChannelAdapter } from '../src/test/mock-channel.js';

const SKIP_E2E = !process.env.LETTA_API_KEY;

describe.skipIf(SKIP_E2E)('e2e: LettaBot', () => {
  let bot: LettaBot;
  let adapter: MockChannelAdapter;

  beforeAll(async () => {
    bot = new LettaBot({ /* config */ });
    adapter = new MockChannelAdapter();
    bot.registerChannel(adapter);
  });

  it('responds to messages', async () => {
    const response = await adapter.simulateMessage('Hi!');
    expect(response.length).toBeGreaterThan(0);
  }, 60000); // 60s timeout for API calls
});

CI/CD

Tests run automatically via GitHub Actions (.github/workflows/test.yml):

Job	Trigger	What it tests
unit	All PRs and pushes	Unit tests only
e2e	Pushes to main	Full E2E with Letta Cloud

E2E tests only run on main because they require secrets that aren't available to fork PRs.

Best Practices

1. Co-locate tests - Put foo.test.ts next to foo.ts
2. Test new code - Add tests for bug fixes and new features
3. Use descriptive names - it('returns null for invalid input') not it('works')
4. Set timeouts - E2E tests need longer timeouts (30-120s)
5. Mock external deps - Don't call real APIs in unit tests

Coverage

To see test coverage:

npm run test:run -- --coverage

Current test coverage focuses on:

• Core utilities (phone, backoff, server)
• Message formatting
• Command parsing
• Channel-specific logic (WhatsApp mentions, group gating)