AssemblyAI CI Integration

Overview

Set up CI/CD pipelines for AssemblyAI transcription projects with unit tests (mocked), integration tests (live API), and cost-controlled test strategies.

Prerequisites

• GitHub repository with Actions enabled
• AssemblyAI API key for testing
• npm/pnpm project configured

Instructions

Step 1: GitHub Actions Workflow

# .github/workflows/assemblyai-tests.yml
name: AssemblyAI Tests

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]

jobs:
  unit-tests:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'
      - run: npm ci
      - run: npm test -- --coverage
        # Unit tests use mocked AssemblyAI client — no API key needed

  integration-tests:
    runs-on: ubuntu-latest
    # Only run on main branch to limit API costs
    if: github.ref == 'refs/heads/main'
    env:
      ASSEMBLYAI_API_KEY: ${{ secrets.ASSEMBLYAI_API_KEY }}
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: '20'
          cache: 'npm'
      - run: npm ci
      - run: npm run test:integration
        timeout-minutes: 5

Step 2: Configure Secrets

# Store API key as GitHub secret
gh secret set ASSEMBLYAI_API_KEY --body "your-test-api-key"

# Use a separate test key with lower quota to control costs
# Get one from https://www.assemblyai.com/app/account

Step 3: Unit Tests (Mocked — Free, Fast)

// tests/unit/transcription.test.ts
import { describe, it, expect, vi, beforeEach } from 'vitest';
import { AssemblyAI } from 'assemblyai';

vi.mock('assemblyai', () => ({
  AssemblyAI: vi.fn().mockImplementation(() => ({
    transcripts: {
      transcribe: vi.fn().mockResolvedValue({
        id: 'mock-transcript-id',
        status: 'completed',
        text: 'Hello world, this is a test transcription.',
        audio_duration: 5.2,
        words: [
          { text: 'Hello', start: 0, end: 300, confidence: 0.99 },
          { text: 'world', start: 310, end: 600, confidence: 0.98 },
        ],
        utterances: [
          { speaker: 'A', text: 'Hello world, this is a test transcription.', start: 0, end: 5200 },
        ],
      }),
      get: vi.fn(),
      list: vi.fn().mockResolvedValue({
        transcripts: [{ id: 'mock-1', status: 'completed' }],
      }),
      delete: vi.fn().mockResolvedValue({}),
    },
    lemur: {
      task: vi.fn().mockResolvedValue({
        request_id: 'mock-lemur-id',
        response: 'This is a greeting recording.',
      }),
      summary: vi.fn().mockResolvedValue({
        response: 'The audio contains a greeting.',
      }),
    },
  })),
}));

describe('TranscriptionService', () => {
  it('should transcribe audio and return text', async () => {
    const client = new AssemblyAI({ apiKey: 'test-key' });
    const result = await client.transcripts.transcribe({
      audio: 'https://example.com/test.wav',
    });

    expect(result.status).toBe('completed');
    expect(result.text).toContain('Hello world');
    expect(result.words).toHaveLength(2);
  });

  it('should handle speaker diarization', async () => {
    const client = new AssemblyAI({ apiKey: 'test-key' });
    const result = await client.transcripts.transcribe({
      audio: 'https://example.com/test.wav',
      speaker_labels: true,
    });

    expect(result.utterances).toBeDefined();
    expect(result.utterances![0].speaker).toBe('A');
  });

  it('should run LeMUR task', async () => {
    const client = new AssemblyAI({ apiKey: 'test-key' });
    const { response } = await client.lemur.task({
      transcript_ids: ['mock-transcript-id'],
      prompt: 'Summarize.',
    });

    expect(response).toBeTruthy();
  });
});

Step 4: Integration Tests (Live API — Controlled)

// tests/integration/assemblyai.test.ts
import { describe, it, expect } from 'vitest';
import { AssemblyAI } from 'assemblyai';

// Use a short, free sample audio to minimize costs
const TEST_AUDIO = 'https://storage.googleapis.com/aai-web-samples/5_common_sports_702.wav';

const skipIfNoKey = !process.env.ASSEMBLYAI_API_KEY;

describe.skipIf(skipIfNoKey)('AssemblyAI Integration', () => {
  const client = new AssemblyAI({
    apiKey: process.env.ASSEMBLYAI_API_KEY!,
  });

  it('should transcribe a short audio file', async () => {
    const transcript = await client.transcripts.transcribe({
      audio: TEST_AUDIO,
    });

    expect(transcript.status).toBe('completed');
    expect(transcript.text).toBeTruthy();
    expect(transcript.audio_duration).toBeGreaterThan(0);
    expect(transcript.words?.length).toBeGreaterThan(0);
  }, 60_000); // 60s timeout for transcription

  it('should list recent transcripts', async () => {
    const page = await client.transcripts.list({ limit: 5 });
    expect(page.transcripts).toBeDefined();
    expect(Array.isArray(page.transcripts)).toBe(true);
  });

  it('should run LeMUR on a transcript', async () => {
    const transcript = await client.transcripts.transcribe({
      audio: TEST_AUDIO,
    });

    const { response } = await client.lemur.task({
      transcript_ids: [transcript.id],
      prompt: 'What is this about? One sentence.',
    });

    expect(response).toBeTruthy();
    expect(response.length).toBeGreaterThan(10);
  }, 90_000);
});

Step 5: Cost-Controlled Testing Strategy

# Only run integration tests on main (not on every PR)
# Use short sample audio (~30s = ~$0.002 per test run)
# Cache transcript IDs across tests when possible

# In package.json:
# "test": "vitest --exclude='**/integration/**'"
# "test:integration": "vitest --include='**/integration/**'"

Output

• Unit test pipeline (mocked, runs on every PR)
• Integration test pipeline (live API, runs on main only)
• GitHub Secrets configured for API key
• Cost-controlled test strategy

Error Handling

Issue	Cause	Solution
Secret not found	Missing GitHub secret	gh secret set ASSEMBLYAI_API_KEY
Integration test timeout	Slow transcription	Increase timeout to 60s+, use short audio
Flaky tests	Network latency	Add retry logic, use vitest.retries(2)
High test costs	Long audio files	Use 30-second sample audio

Resources

• GitHub Actions Documentation
• Vitest Documentation
• AssemblyAI Node SDK

Next Steps

For deployment patterns, see assemblyai-deploy-integration.