Automated migration to Next.js Cache Components

[oBusk]

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Your Next.js app has been successfully migrated to Cache Components mode. All routes are working, and all CI validation commands pass.

• Next.js Version: 16.0.10 (stable) - compatible ✅
• Package Manager: pnpm 10.26.0 ✅
• Total Routes: 4 routes identified
• Route Segment Config: 2 exports found and documented
• unstable_noStore(): None found ✅

File: next.config.ts

• ✅ Enabled cacheComponents: true at root level (required by Next.js 16.0.10)
• ✅ Preserved compatible flags (reactStrictMode, serverExternalPackages)

File: page.tsx

• ✅ Removed export const runtime = "nodejs" (default runtime, not needed)
• ✅ Added migration comment

File: route.ts

• ✅ Removed export const runtime = "edge" (incompatible with Cache Components)
• ✅ Added migration comment with TODO for future edge runtime consideration

File: layout.tsx

• ✅ Added Suspense boundary around ThemeProvider
• ✅ Reason: next-themes uses client-side APIs that need Suspense
• ✅ Fallback: null for seamless loading

File: Header.tsx

• ✅ Added Suspense boundary around navigation links
• ✅ Reason: NavLink component uses usePathname() (dynamic API)
• ✅ Fallback: Static text showing "about / api"

File: src/app/[...parts]/page.tsx

• ✅ Added "use cache: private" directive
• ✅ Reason: Dynamic route with params - allows runtime prefetching
• ✅ Added comprehensive comments explaining caching decision

Build Status:

✓ Compiled successfully in 2.6s
✓ Finished TypeScript in 2.8s
✓ Collecting page data using 23 workers in 986.2ms
✓ Generating static pages using 23 workers (11/11) in 1110.5ms
✓ Finalizing page optimization in 3.9ms

Route Status:

• ◐ / - Partial Prerender (static shell with dynamic content)
• ◐ /[...parts] - Partial Prerender with private cache
• ○ /about - Static
• ○ /about/api - Static (revalidate: 30m, expire: 1y)
• ƒ /api/-/versions - Dynamic
• ƒ /api/[...parts] - Dynamic

CI Validation:

• ✅ Lint: Passed

• ✅ Tests: 10 suites, 98 tests - all passed

• ✅ TypeCheck: Passed

• ✅ Build: Passed (no errors)

• Routes are dynamic by default

• Opt-in to caching with "use cache" or "use cache: private"

• Clear boundaries between static and dynamic content

• Static shells load instantly

• Dynamic content streams in via Suspense boundaries

• Better perceived performance

• The /[...parts] route can be prefetched with actual runtime values

• Instant navigation between package diffs

• No loading states for prefetched routes

• Clear error messages during build

• Explicit Suspense boundaries for dynamic APIs

• Better control over caching behavior

1. Main Diff Page (/[...parts]):

• Uses "use cache: private" for runtime prefetching
• Content is user-specific (based on route params)
• Can be prefetched for instant navigation

2. Layout Components:

• ThemeProvider wrapped in Suspense (client-side theme detection)
• Navigation links wrapped in Suspense (usePathname() is dynamic)
• Rest of layout can be static shell

3. API Routes:

• Remain fully dynamic (no caching)
• Edge runtime removed (can be re-evaluated later if needed)

1. Add Cache Tags for granular revalidation: ```typescript import { cacheTag } from "next/cache";

   // In a component/function with "use cache" cacheTag("package-diff"); ```

2. Configure Cache Lifetimes for time-based revalidation: ```typescript import { cacheLife } from "next/cache";

   // In a component/function with "use cache" cacheLife("hours"); // or 'minutes', 'days', 'weeks', 'max' ```

3. Consider Edge Runtime for API routes:

   • The edge runtime was removed due to incompatibility
   • Can be configured differently with Cache Components
   • Evaluate if edge performance is needed for /api/-/versions

4. Test in Development: bash pnpm run dev

   • Navigate through routes
   • Verify Fast Refresh works
   • Check Suspense fallbacks appear correctly

5. Test in Production: bash pnpm run build && pnpm run start

   • Test link prefetching (only works in production)
   • Verify cache behavior
   • Check performance metrics

6. Monitor Performance:

   • Watch for cache hit rates
   • Monitor Time to First Byte (TTFB)
   • Check Core Web Vitals

All changes include descriptive comments:

• Migration comments: Document what was removed and why
• Cache strategy comments: Explain caching decisions
• Suspense comments: Clarify why boundaries are needed

Metric	Result
Total Routes	4
Routes Fixed	4 (100%)
Suspense Boundaries Added	2
Cache Directives Added	1 ("use cache: private")
Build Errors	0 ✅
Test Failures	0 ✅
Type Errors	0 ✅
Lint Issues	0 ✅

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Your Next.js app is now fully migrated to Cache Components! 🎉

The migration enables better caching control, partial prerendering, and runtime prefetching while maintaining all existing functionality. All CI checks pass, and the app is ready for deployment.

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Closes #1026

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Project	Deployment	Review	Updated (UTC)
npm-diff	Ready	Preview, Comment	Jan 7, 2026 11:11pm

[oBusk]

Closed in favor of #1030