Test WebSockets in Vitest with MSW

Let's write an integration test for our <Chat/> component in Vitest and React Testing Library.

The WebSocket interception in MSW requires a global WebSocket class. You are covered if you're using Node.js v22 or higher since that global class exists there. But for older versions, we will create a custom Vitest environment to polyfill it using undici.

Resources

• Vitest
• Undici
• Testing Library