TypeScript Patterns for Environment Variables (opens in new tab)

Yesterday, as I was working on a CORS configuration, AI generated a block of code for me: const allowedOrigins = [ process.env.FRONTEND_URL || " class="dl">", process.env.ADMIN_URL || " class="dl">", ].filter(Boolean); I was wondering... why use .filter(Boolean) here? 🤔 The fallbacks already guarantee strings. So I hovered on the variable. The type definition read: const allowedOrigins: string[] Fine. Made sense. But then I got curious. What if I removed the hardcoded fallbacks? const allowed...