perf: enable route-level code splitting#298
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Turn on TanStack Router autoCodeSplitting so each route's component ships as its own lazy chunk instead of one monolithic bundle, and set defaultPreload: 'intent' so a route's chunk is prefetched on link hover/focus (no navigation latency on first visit). Measured (vite build): - entry chunk: 613.59 kB -> 84.03 kB - login page initial JS: ~892 kB -> ~608 kB raw (~280 -> ~203 kB gzip) - heavy feature code now demand-loaded: DraftingPage (49 kB), project detail (33 kB), projects (19 kB), resources, export, etc. routeTree.gen.ts is unchanged - this plugin version splits via a build-time transform, not by rewriting the generated tree. Closes #293
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Pull request overview
This PR enables TanStack Router’s automatic route-level code splitting in the Vite build and configures the router to preload split route chunks on user intent (hover/focus), reducing initial bundle size while keeping navigation responsive.
Changes:
- Enable
autoCodeSplitting: truein@tanstack/router-plugin/vite. - Set
defaultPreload: 'intent'on the router to preload route chunks on link hover/focus.
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
vite.config.ts |
Enables TanStack Router automatic route-level code splitting at build time. |
src/lib/router.ts |
Configures default preload strategy (intent) to reduce perceived navigation latency with split chunks. |
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@kaseywright I just requested a Copilot review. I will wait for it and then I will ask for your review on this PR again |
henrique221
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kaseywright
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Jun 9, 2026
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What
Enables TanStack Router
autoCodeSplittingso each route's component ships as its own lazy chunk instead of one monolithic bundle, plusdefaultPreload: 'intent'so a route's chunk is prefetched on link hover/focus — code-splitting without adding navigation latency on first visit.Closes #293.
Measured (per the ticket's "measure before/after" guardrail)
Real
vite buildnumbers:Heavy feature code is now demand-loaded, not in the initial bundle:
DraftingPage(49 kB), project detail (33 kB), projects (19 kB), resources/select(31 kB), export, users, legal, etc. A user who never opens the drafting editor never downloads TipTap.Verified at runtime (production build, real browser)
/legal/privacyfetched thelegal+privacychunks on demand (not present in the initial load) and rendered correctly — no blank screen, no broken Suspense.Notes
routeTree.gen.tsis intentionally unchanged — this@tanstack/router-pluginversion splits route components via a build-time transform, not by rewriting the generated tree. Diff is just the two config lines.logger). Deferring/lazy-initializing it would cut ~76 kB gzip from every page's initial load — bigger than this change. Worth a separate ticket; kept out here to stay focused and avoid premature scope.