Next.js 16 Enhances Type Safety with Async PageProps & Typed Routes

Next.js TypeScript plugin

Next.js includes a custom TypeScript plugin that provides enhanced type-checking beyond standard tsc, understanding Next.js concepts like file-based routing and Server vs. Client Components. Enabling this plugin via VS Code’s TypeScript version selection ensures access to Next.js-specific type rules and improved IntelliSense.

Next.js has quietly become one of the most type-safe full-stack frameworks, yet many teams underutilize its features. The framework’s TypeScript plugin, statically typed routes, and route-aware type helpers offer significant improvements in preventing runtime bugs and enhancing developer experience.

Key Insights

• Next.js TypeScript plugin: Improves type-checking beyond standard tsc.
• Statically Typed Routes: Prevent typos and invalid navigation by generating route definitions at build time.
• Route-Aware Type Helpers: Provide concise and automatically synchronized types for page and layout props, and route context.

Working Example

import type { NextConfig } from 'next'
const nextConfig: NextConfig = {
  typedRoutes: true,
}
export default nextConfig

export default async function Details(props: PageProps<"/details/[slotId]">) {
  const { slotId } = await props.params;
  const { name } = await props.searchParams;
  return (
    <div>
      Slot: {slotId} <br />
      Name: {name}
    </div>
  );
}

Practical Applications

• E-commerce: Using typed routes to ensure valid product URLs, preventing 404 errors and improving SEO.
• Pitfall: Disabling the Next.js TypeScript plugin can lead to runtime errors due to missing type checks for Next.js-specific APIs.

References:

• https://dev.to/bharathkumar28/nextjs-16-type-safety-async-pageprops-typed-routes-3ilc