Cloudflare Workers Testing

# Update dependencies
bun add -D vitest@^2.1.8 @cloudflare/vitest-pool-workers@^0.7.2

# Update vitest.config.ts (new pool configuration format)
export default defineWorkersConfig({
  test: {
    poolOptions: {
      workers: {
        wrangler: { configPath: './wrangler.jsonc' },
        miniflare: { compatibilityDate: '2025-01-27' }
      }
    }
  }
});

bun add -D vitest @cloudflare/vitest-pool-workers

import { defineWorkersConfig } from '@cloudflare/vitest-pool-workers/config';

export default defineWorkersConfig({
  test: {
    poolOptions: {
      workers: {
        wrangler: { configPath: './wrangler.jsonc' },
        miniflare: {
          compatibilityDate: '2025-01-27',
          compatibilityFlags: ['nodejs_compat']
        }
      }
    }
  }
});

import { describe, it, expect } from 'vitest';
import { env, createExecutionContext, waitOnExecutionContext } from 'cloudflare:test';
import worker from '../src/index';

describe('Worker', () => {
  it('responds with 200', async () => {
    const request = new Request('http://example.com/');
    const ctx = createExecutionContext();
    const response = await worker.fetch(request, env, ctx);
    await waitOnExecutionContext(ctx);

    expect(response.status).toBe(200);
  });
});

bun test
# or
bunx vitest

import { env } from 'cloudflare:test';

it('queries D1', async () => {
  const result = await env.DB.prepare('SELECT * FROM users').all();
  expect(result.results).toHaveLength(0); // Fresh isolated DB per test
});

// Don't manually create env object
const env = { DB: mockDB }; // ❌ Won't use real D1 binding

it('handles async operations', async () => {
  const ctx = createExecutionContext();
  const response = await worker.fetch(request, env, ctx);
  await waitOnExecutionContext(ctx); // ✅ Ensures ctx.waitUntil completes

  expect(response.status).toBe(200);
});

it('missing wait', async () => {
  const ctx = createExecutionContext();
  const response = await worker.fetch(request, env, ctx);
  // ❌ Missing waitOnExecutionContext - ctx.waitUntil tasks may not complete
  expect(response.status).toBe(200);
});

describe('KV Operations', () => {
  it('test 1: writes to KV', async () => {
    await env.CACHE.put('key', 'value1');
    const val = await env.CACHE.get('key');
    expect(val).toBe('value1'); // ✅ Isolated
  });

  it('test 2: clean state', async () => {
    const val = await env.CACHE.get('key');
    expect(val).toBeNull(); // ✅ Test 1's data doesn't leak here
  });
});

// vitest.config.ts
export default defineWorkersConfig({
  test: {
    poolOptions: {
      workers: {
        wrangler: { configPath: './wrangler.jsonc' } // ✅ Reads bindings from wrangler
      }
    }
  }
});

// vitest.config.ts
export default defineWorkersConfig({
  test: {
    poolOptions: {
      workers: {
        // ❌ No wrangler config - bindings won't be available
        miniflare: { compatibilityDate: '2025-01-27' }
      }
    }
  }
});

// vitest.config.ts
miniflare: {
  compatibilityDate: '2025-01-27' // ✅ Matches wrangler.jsonc
}

// wrangler.jsonc
{
  "compatibility_date": "2025-01-27"
}

import { env } from 'cloudflare:test';

it('queries D1', async () => {
  // Insert test data
  await env.DB.prepare('INSERT INTO users (name) VALUES (?)').bind('Alice').run();

  // Query
  const result = await env.DB.prepare('SELECT * FROM users WHERE name = ?').bind('Alice').first();
  expect(result?.name).toBe('Alice');
});

it('reads from KV', async () => {
  await env.CACHE.put('test-key', 'test-value');
  const value = await env.CACHE.get('test-key');
  expect(value).toBe('test-value');
});

it('uploads to R2', async () => {
  await env.BUCKET.put('file.txt', 'Hello World');
  const object = await env.BUCKET.get('file.txt');
  expect(await object?.text()).toBe('Hello World');
});

it('interacts with Durable Object', async () => {
  const id = env.COUNTER.idFromName('test-counter');
  const stub = env.COUNTER.get(id);

  const response = await stub.fetch('http://fake/increment');
  const data = await response.json();
  expect(data.count).toBe(1);
});

import { validateInput } from '../src/utils/validator';

it('validates input', () => {
  const result = validateInput({ name: 'Alice', age: 30 });
  expect(result.valid).toBe(true);
});

import worker from '../src/index';
import { env, createExecutionContext, waitOnExecutionContext } from 'cloudflare:test';

it('handles full request flow', async () => {
  const request = new Request('http://example.com/api/users', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ name: 'Alice' })
  });

  const ctx = createExecutionContext();
  const response = await worker.fetch(request, env, ctx);
  await waitOnExecutionContext(ctx);

  expect(response.status).toBe(201);
  const user = await response.json();
  expect(user.name).toBe('Alice');
});

export default defineWorkersConfig({
  test: {
    coverage: {
      provider: 'v8',
      reporter: ['text', 'json', 'html'],
      include: ['src/**/*.ts'],
      exclude: ['src/**/*.test.ts', 'src/**/*.spec.ts'],
      thresholds: {
        lines: 80,
        functions: 80,
        branches: 80,
        statements: 80
      }
    }
  }
});

bunx vitest run --coverage

it('creates user via API', async () => {
  const request = new Request('http://example.com/api/users', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ name: 'Bob', email: 'bob@example.com' })
  });

  const ctx = createExecutionContext();
  const response = await worker.fetch(request, env, ctx);
  await waitOnExecutionContext(ctx);

  expect(response.status).toBe(201);

  // Verify DB insert
  const user = await env.DB.prepare('SELECT * FROM users WHERE email = ?')
    .bind('bob@example.com')
    .first();
  expect(user?.name).toBe('Bob');
});

it('caches API responses', async () => {
  // First request (cache miss)
  const req1 = new Request('http://example.com/api/data');
  const ctx1 = createExecutionContext();
  const res1 = await worker.fetch(req1, env, ctx1);
  await waitOnExecutionContext(ctx1);

  expect(res1.headers.get('X-Cache')).toBe('MISS');

  // Second request (cache hit)
  const req2 = new Request('http://example.com/api/data');
  const ctx2 = createExecutionContext();
  const res2 = await worker.fetch(req2, env, ctx2);
  await waitOnExecutionContext(ctx2);

  expect(res2.headers.get('X-Cache')).toBe('HIT');
});

it('handles file upload', async () => {
  const formData = new FormData();
  formData.append('file', new Blob(['test content'], { type: 'text/plain' }), 'test.txt');

  const request = new Request('http://example.com/upload', {
    method: 'POST',
    body: formData
  });

  const ctx = createExecutionContext();
  const response = await worker.fetch(request, env, ctx);
  await waitOnExecutionContext(ctx);

  expect(response.status).toBe(200);

  // Verify R2 upload
  const object = await env.BUCKET.get('test.txt');
  expect(await object?.text()).toBe('test content');
});

it('maintains counter state', async () => {
  const id = env.COUNTER.idFromName('my-counter');
  const stub = env.COUNTER.get(id);

  // Increment 3 times
  for (let i = 0; i < 3; i++) {
    await stub.fetch('http://fake/increment');
  }

  // Verify state
  const response = await stub.fetch('http://fake/value');
  const data = await response.json();
  expect(data.count).toBe(3);
});

it('processes queue messages', async () => {
  const messages = [
    { id: '1', body: { action: 'email', to: 'user@example.com' }, timestamp: new Date() }
  ];

  // Simulate queue batch
  await worker.queue(
    {
      queue: 'my-queue',
      messages,
      retryAll: () => {},
      ackAll: () => {}
    },
    env
  );

  // Verify processing (check DB, logs, etc.)
  const log = await env.DB.prepare('SELECT * FROM email_log WHERE id = ?').bind('1').first();
  expect(log?.status).toBe('sent');
});

import { env } from 'cloudflare:test'; // ✅ Add this import