perf(router-core): fuse static route node construction

[Sheraff]

Summary

• select the case-specific static key and child map once, then share lookup and node construction
• preserve one explicit sensitivity branch after the runtime benchmark gate
• add focused sensitivity, prefix-reuse, route-mask tests and a static construction benchmark

Bundle impact

Across the exact 17-scenario matrix, every scenario is 162 raw bytes smaller, gzip improves by 22-45 bytes, and initial gzip improves by 22-44 bytes. react-router.minimal improves by 162 raw / 36 gzip / 161 Brotli bytes. Brotli is mixed across the matrix (-161 to +43 bytes) and is disclosed in the checked-in result report.

Runtime

Repeated focused runs show the insensitive distributions about 6-7% faster; sensitive-unique and narrowed sensitive-shared distributions are neutral. The final implementation keeps one real sensitivity branch because an earlier branchless form produced a questionable sensitive-path result.

Validation

• router-core unit: 1,526 passed, 3 expected failures
• router-core types: TypeScript 5.6 through 7.0 passed
• router-core ESLint: 0 errors
• generator CLI React e2e: 3 passed
• full 17-scenario bundle matrix passed
• five independent reviews approved the exact production HEAD

Integration note

This overlaps the parseSegments construction region changed by #7974. Whichever PR lands second must be rebased and have the benchmark and full bundle matrix rerun.

Summary by CodeRabbit

• Performance
  • Improved static route-tree construction efficiency, reducing redundant processing and supporting smaller bundles in tested scenarios.
• Bug Fixes
  • Fixed case-sensitive and case-insensitive route matching across shared and differently cased route paths.
  • Preserved route-level case-sensitivity overrides when the overall routing configuration uses a different default.
• Documentation
  • Added documentation covering performance results, compatibility, validation, and integration considerations.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 031ebdbf-8844-4e93-924a-a8c22513af11

📥 Commits

Reviewing files that changed from the base of the PR and between 697ebb6 and 6457582.

📒 Files selected for processing (4)

• RESULT-optimization-fused-static-route-nodes.md
• packages/router-core/src/new-process-route-tree.ts
• packages/router-core/tests/new-process-route-tree.test.ts
• packages/router-core/tests/route-tree-static-construction.bench.ts

---

📝 Walkthrough

Walkthrough

The route-tree parser now fuses case-sensitive and case-insensitive static-node construction. Tests cover node reuse and matching behavior. A benchmark measures shared and unique static prefixes. Documentation records results and compatibility details.

Changes

Static route-node construction

Layer / File(s)	Summary
Fuse case-aware static-node construction packages/router-core/src/new-process-route-tree.ts, packages/router-core/tests/new-process-route-tree.test.ts	parseSegments selects the appropriate static-child map and shares lookup and creation logic. Tests cover case-insensitive node reuse, route-level overrides, and uppercase route matching.
Validate construction and measurements packages/router-core/tests/route-tree-static-construction.bench.ts, RESULT-optimization-fused-static-route-nodes.md	Benchmarks cover shared and unique prefixes for both sensitivity modes. Documentation records bundle-size results, runtime benchmarks, compatibility guarantees, and validation coverage.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Possibly related PRs

• TanStack/router#7969: Both changes modify route-tree parsing, but this PR targets static-node construction while that PR targets dynamic-sibling sorting.
• TanStack/router#7974: Both changes modify parseSegments construction logic, with this PR targeting static nodes and that PR targeting dynamic nodes.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the primary performance change: fusing static route node construction in router-core.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches 💡 1

🛠️ Fix failing CI checks 💡

• Create stacked PR
• Commit on current branch

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch codex/fuse-static-route-nodes

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}

[nx-cloud]

View your CI Pipeline Execution ↗ for commit f59c15d

Command	Status	Duration	Result
nx affected --targets=test:eslint,test:unit,tes...	❌ Failed	9m 11s	View ↗
nx run-many --target=build --exclude=examples/*...	✅ Succeeded	28s	View ↗

---

☁️ Nx Cloud last updated this comment at 2026-08-06 10:39:37 UTC

[github-actions]

🚀 Changeset Version Preview

5 package(s) bumped directly, 18 bumped as dependents.

🟩 Patch bumps

Package	Version	Reason
@tanstack/react-router	1.170.20 → 1.170.21	Changeset
@tanstack/router-core	1.171.17 → 1.171.18	Changeset
@tanstack/solid-router	1.170.20 → 1.170.21	Changeset
@tanstack/start-server-core	1.169.20 → 1.169.21	Changeset
@tanstack/vue-router	1.170.19 → 1.170.20	Changeset
@tanstack/react-start	1.168.37 → 1.168.38	Dependent
@tanstack/react-start-client	1.168.18 → 1.168.19	Dependent
@tanstack/react-start-rsc	0.1.36 → 0.1.37	Dependent
@tanstack/react-start-server	1.167.25 → 1.167.26	Dependent
@tanstack/router-cli	1.167.23 → 1.167.24	Dependent
@tanstack/router-generator	1.167.23 → 1.167.24	Dependent
@tanstack/router-plugin	1.168.25 → 1.168.26	Dependent
@tanstack/router-vite-plugin	1.167.25 → 1.167.26	Dependent
@tanstack/solid-start	1.168.36 → 1.168.37	Dependent
@tanstack/solid-start-client	1.168.18 → 1.168.19	Dependent
@tanstack/solid-start-server	1.167.25 → 1.167.26	Dependent
@tanstack/start-client-core	1.170.16 → 1.170.17	Dependent
@tanstack/start-plugin-core	1.171.28 → 1.171.29	Dependent
@tanstack/start-static-server-functions	1.167.21 → 1.167.22	Dependent
@tanstack/start-storage-context	1.167.19 → 1.167.20	Dependent
@tanstack/vue-start	1.168.35 → 1.168.36	Dependent
@tanstack/vue-start-client	1.167.21 → 1.167.22	Dependent
@tanstack/vue-start-server	1.167.25 → 1.167.26	Dependent

[github-actions]

Bundle Size Benchmarks

• Commit: 44554f12fe15
• Measured at: 2026-08-06T10:32:23.615Z
• Baseline source: history:697ebb6ddbd4
• Dashboard: bundle-size history

The following scenarios have bundle-size changes compared with the baseline:

Scenario	Current (gzip)	Delta vs baseline	Initial gzip	Raw	Brotli	Trend
react-router.minimal	87.07 KiB	-36 B (-0.04%)	86.94 KiB	268.97 KiB	75.76 KiB	████▂▂▂▂▂▁▂▁
react-router.full	90.87 KiB	-32 B (-0.03%)	90.73 KiB	280.93 KiB	79.12 KiB	████▃▃▃▃▃▁▂▁
solid-router.minimal	34.77 KiB	-27 B (-0.08%)	34.64 KiB	99.81 KiB	31.39 KiB	████▂▂▂▂▂▁▁▁
solid-router.full	39.86 KiB	-37 B (-0.09%)	39.74 KiB	114.99 KiB	35.92 KiB	████▂▂▂▂▂▁▁▁
vue-router.minimal	52.06 KiB	-32 B (-0.06%)	51.94 KiB	142.96 KiB	46.90 KiB	████▂▂▂▂▂▁▁▁
vue-router.full	58.02 KiB	-33 B (-0.06%)	57.89 KiB	161.63 KiB	52.10 KiB	████▂▂▂▂▂▁▁▁
react-start.minimal	100.55 KiB	-45 B (-0.04%)	100.42 KiB	312.13 KiB	87.27 KiB	███████▁▁▁▁▁
react-start.deferred-hydration	101.29 KiB	-44 B (-0.04%)	100.44 KiB	313.50 KiB	87.91 KiB	███████▁▁▁▁▁
react-start.full	103.90 KiB	-24 B (-0.02%)	103.76 KiB	322.07 KiB	90.17 KiB	███████▁▁▁▁▁
react-start.rsbuild.minimal	100.21 KiB	-22 B (-0.02%)	100.04 KiB	316.63 KiB	86.33 KiB	▁▁▁▁▂▂▂█████
react-start.rsbuild.minimal-iife	100.62 KiB	-22 B (-0.02%)	100.46 KiB	317.56 KiB	86.78 KiB	▁▁▁▁▂▂▂█████
react-start.rsbuild.full	103.54 KiB	-26 B (-0.02%)	103.37 KiB	326.72 KiB	89.19 KiB	▁▁▁▁▃▃▃█████
solid-start.minimal	48.14 KiB	-41 B (-0.08%)	48.01 KiB	141.95 KiB	42.76 KiB	███████▁▁▁▁▁
solid-start.deferred-hydration	51.40 KiB	-42 B (-0.08%)	48.07 KiB	149.99 KiB	45.80 KiB	███████▁▁▁▁▁
solid-start.full	53.39 KiB	-41 B (-0.07%)	53.26 KiB	157.68 KiB	47.41 KiB	████▆▆▆▁▁▁▁▁
vue-start.minimal	68.94 KiB	-32 B (-0.05%)	68.81 KiB	194.96 KiB	61.28 KiB	████▆▆▆▁▁▁▁▁
vue-start.full	72.90 KiB	-34 B (-0.05%)	72.77 KiB	207.46 KiB	64.67 KiB	████▆▆▆▁▁▁▁▁

Current gzip tracks all emitted client JS chunks. Initial gzip tracks only the entry/import graph. Trend sparkline is historical current gzip ending with this PR measurement; lower is better.

[pkg-pr-new]

More templates

• tanstack-router-react-example-authenticated-routes
• tanstack-router-react-example-authenticated-routes-firebase
• tanstack-router-react-example-basic
• tanstack-router-react-example-basic-default-search-params
• tanstack-router-react-example-basic-devtools-panel
• tanstack-router-react-example-basic-file-based
• tanstack-router-react-example-basic-non-nested-devtools
• tanstack-router-react-example-react-query
• tanstack-router-react-example-basic-react-query-file-based
• tanstack-router-react-example-basic-ssr-file-based
• tanstack-router-react-example-basic-ssr-streaming-file-based
• tanstack-router-react-example-basic-virtual-file-based
• tanstack-router-react-example-basic-virtual-inside-file-based
• tanstack-router-react-example-deferred-data
• tanstack-router-i18n-paraglide
• tanstack-router-react-example-kitchen-sink
• tanstack-router-react-example-kitchen-sink-file-based
• tanstack-router-react-example-kitchen-sink-react-query
• tanstack-router-react-example-kitchen-sink-react-query-file-based
• tanstack-router-react-example-large-file-based
• tanstack-router-react-example-location-masking
• tanstack-router-react-example-navigation-blocking
• tanstack-router-react-example-quickstart
• tanstack-router-react-example-quickstart-esbuild-file-based
• tanstack-router-react-example-quickstart-file-based
• tanstack-router-react-example-quickstart-rspack-file-based
• tanstack-router-react-example-quickstart-webpack-file-based
• router-monorepo-react-query
• router-mono-simple
• router-mono-simple-lazy
• tanstack-router-react-example-scroll-restoration
• tanstack-search-validator-adapters
• tanstack-start-example-bare
• tanstack-start-example-basic
• tanstack-start-example-basic-auth
• tanstack-router-react-example-basic-authjs
• tanstack-start-example-basic-cloudflare
• tanstack-start-example-basic-react-query
• tanstack-start-example-basic-rsbuild
• tanstack-start-example-basic-static
• tanstack-start-bun-hosting
• tanstack-start-example-clerk-basic
• tanstack-start-example-convex-trellaux
• tanstack-start-example-counter
• tanstack-start-i18n-paraglide
• tanstack-start-example-large
• tanstack-start-example-material-ui
• tanstack-start-example-rscs
• tanstack-start-streaming-data-from-server-functions
• tanstack-start-example-supabase-basic
• tanstack-start-tailwind-v4
• tanstack-start-example-trellaux
• tanstack-start-example-workos
• tanstack-router-react-example-view-transitions
• tanstack-router-react-example-with-framer-motion
• tanstack-router-react-example-with-trpc
• tanstack-router-react-example-with-trpc-react-query
• tanstack-router-solid-example-authenticated-routes
• tanstack-router-solid-example-authenticated-routes-firebase
• tanstack-router-solid-example-basic
• tanstack-router-solid-example-basic-default-search-params
• tanstack-router-solid-example-basic-devtools-panel
• tanstack-router-solid-example-basic-file-based
• tanstack-router-solid-example-basic-non-nested-devtools
• tanstack-router-solid-example-basic-solid-query
• tanstack-router-solid-example-basic-solid-query-file-based
• tanstack-router-solid-example-basic-ssr-file-based
• tanstack-router-solid-example-basic-ssr-streaming-file-based
• tanstack-router-solid-example-basic-virtual-file-based
• tanstack-router-solid-example-basic-virtual-inside-file-based
• tanstack-router-solid-example-deferred-data
• tanstack-router-solid-i18n-paraglide
• tanstack-router-solid-example-kitchen-sink
• tanstack-router-solid-example-kitchen-sink-file-based
• tanstack-router-solid-example-kitchen-sink-solid-query
• tanstack-router-solid-example-kitchen-sink-solid-query-file-based
• tanstack-router-solid-example-large-file-based
• tanstack-router-solid-example-location-masking
• tanstack-router-solid-example-navigation-blocking
• tanstack-router-solid-example-quickstart
• tanstack-router-solid-example-quickstart-esbuild-file-based
• tanstack-router-solid-example-quickstart-file-based
• tanstack-router-solid-example-quickstart-rspack-file-based
• tanstack-router-solid-example-quickstart-webpack-file-based
• @tanstack/router-solid-mono-simple
• router-solid-mono-simple-lazy
• router-solid-monorepo-solid-query
• tanstack-router-solid-example-scroll-restoration
• tanstack-solid-router-search-validator-adapters
• tanstack-solid-start-example-basic
• tanstack-solid-start-example-basic-auth
• tanstack-solid-start-example-basic-authjs
• tanstack-solid-start-example-basic-cloudflare
• tanstack-solid-start-example-basic-netlify
• tanstack-solid-start-example-basic-nitro
• tanstack-start-example-basic-solid-query
• tanstack-solid-start-example-basic-static
• tanstack-solid-start-bun-hosting
• tanstack-solid-start-example-convex-better-auth
• tanstack-solid-start-example-counter
• tanstack-solid-start-i18n-paraglide
• tanstack-solid-start-example-large
• tanstack-solid-start-streaming-data-from-server-functions
• tanstack-solid-start-example-supabase-basic
• tanstack-solid-start-tailwind-v4
• tanstack-router-solid-example-view-transitions
• tanstack-router-solid-example-with-framer-motion
• tanstack-router-solid-example-with-trpc
• tanstack-router-vue-example-basic-jsx
• tanstack-router-vue-example-basic-file-based-jsx
• tanstack-router-vue-example-basic-file-based-sfc

@tanstack/arktype-adapter

npm i https://pkg.pr.new/@tanstack/arktype-adapter@7981

@tanstack/eslint-plugin-router

npm i https://pkg.pr.new/@tanstack/eslint-plugin-router@7981

@tanstack/eslint-plugin-start

npm i https://pkg.pr.new/@tanstack/eslint-plugin-start@7981

@tanstack/history

npm i https://pkg.pr.new/@tanstack/history@7981

@tanstack/nitro-v2-vite-plugin

npm i https://pkg.pr.new/@tanstack/nitro-v2-vite-plugin@7981

@tanstack/react-router

npm i https://pkg.pr.new/@tanstack/react-router@7981

@tanstack/react-router-devtools

npm i https://pkg.pr.new/@tanstack/react-router-devtools@7981

@tanstack/react-router-ssr-query

npm i https://pkg.pr.new/@tanstack/react-router-ssr-query@7981

@tanstack/react-start

npm i https://pkg.pr.new/@tanstack/react-start@7981

@tanstack/react-start-client

npm i https://pkg.pr.new/@tanstack/react-start-client@7981

@tanstack/react-start-rsc

npm i https://pkg.pr.new/@tanstack/react-start-rsc@7981

@tanstack/react-start-server

npm i https://pkg.pr.new/@tanstack/react-start-server@7981

@tanstack/router-cli

npm i https://pkg.pr.new/@tanstack/router-cli@7981

@tanstack/router-core

npm i https://pkg.pr.new/@tanstack/router-core@7981

@tanstack/router-devtools

npm i https://pkg.pr.new/@tanstack/router-devtools@7981

@tanstack/router-devtools-core

npm i https://pkg.pr.new/@tanstack/router-devtools-core@7981

@tanstack/router-generator

npm i https://pkg.pr.new/@tanstack/router-generator@7981

@tanstack/router-plugin

npm i https://pkg.pr.new/@tanstack/router-plugin@7981

@tanstack/router-ssr-query-core

npm i https://pkg.pr.new/@tanstack/router-ssr-query-core@7981

@tanstack/router-utils

npm i https://pkg.pr.new/@tanstack/router-utils@7981

@tanstack/router-vite-plugin

npm i https://pkg.pr.new/@tanstack/router-vite-plugin@7981

@tanstack/solid-router

npm i https://pkg.pr.new/@tanstack/solid-router@7981

@tanstack/solid-router-devtools

npm i https://pkg.pr.new/@tanstack/solid-router-devtools@7981

@tanstack/solid-router-ssr-query

npm i https://pkg.pr.new/@tanstack/solid-router-ssr-query@7981

@tanstack/solid-start

npm i https://pkg.pr.new/@tanstack/solid-start@7981

@tanstack/solid-start-client

npm i https://pkg.pr.new/@tanstack/solid-start-client@7981

@tanstack/solid-start-server

npm i https://pkg.pr.new/@tanstack/solid-start-server@7981

@tanstack/start-client-core

npm i https://pkg.pr.new/@tanstack/start-client-core@7981

@tanstack/start-fn-stubs

npm i https://pkg.pr.new/@tanstack/start-fn-stubs@7981

@tanstack/start-plugin-core

npm i https://pkg.pr.new/@tanstack/start-plugin-core@7981

@tanstack/start-server-core

npm i https://pkg.pr.new/@tanstack/start-server-core@7981

@tanstack/start-static-server-functions

npm i https://pkg.pr.new/@tanstack/start-static-server-functions@7981

@tanstack/start-storage-context

npm i https://pkg.pr.new/@tanstack/start-storage-context@7981

@tanstack/valibot-adapter

npm i https://pkg.pr.new/@tanstack/valibot-adapter@7981

@tanstack/virtual-file-routes

npm i https://pkg.pr.new/@tanstack/virtual-file-routes@7981

@tanstack/vue-router

npm i https://pkg.pr.new/@tanstack/vue-router@7981

@tanstack/vue-router-devtools

npm i https://pkg.pr.new/@tanstack/vue-router-devtools@7981

@tanstack/vue-router-ssr-query

npm i https://pkg.pr.new/@tanstack/vue-router-ssr-query@7981

@tanstack/vue-start

npm i https://pkg.pr.new/@tanstack/vue-start@7981

@tanstack/vue-start-client

npm i https://pkg.pr.new/@tanstack/vue-start-client@7981

@tanstack/vue-start-server

npm i https://pkg.pr.new/@tanstack/vue-start-server@7981

@tanstack/zod-adapter

npm i https://pkg.pr.new/@tanstack/zod-adapter@7981

commit: f59c15d

[codspeed-hq]

Merging this PR will regress 3 benchmarks

⚠️ Different runtime environments detected

Some benchmarks with significant performance changes were compared across different runtime environments,
which may affect the accuracy of the results.

Open the report in CodSpeed to investigate

⚡ 8 improved benchmarks
❌ 3 regressed benchmarks
✅ 169 untouched benchmarks

Warning

Please fix the performance issues or acknowledge them on CodSpeed.

Performance Changes

	Mode	Benchmark	BASE	HEAD	Efficiency
❌	Memory	mem server peak-large-page (react)	1.7 MB	2.2 MB	-21.57%
❌	Memory	mem server error-paths unmatched (react)	317.5 KB	373.1 KB	-14.9%
❌	Simulation	ssr server-fn during document ssr (react)	62.9 ms	65.7 ms	-4.27%
⚡	Memory	mem server server-fn-churn (vue)	4,147.3 KB	270.5 KB	×15
⚡	Memory	mem server error-paths unmatched (vue)	2,142.1 KB	485.8 KB	×4.4
⚡	Memory	mem server error-paths redirect (solid)	388 KB	289.2 KB	+34.18%
⚡	Memory	mem server error-paths redirect (vue)	338.6 KB	306.4 KB	+10.52%
⚡	Memory	mem client navigation-churn (solid)	580.3 KB	537.3 KB	+7.99%
⚡	Memory	mem client navigation-churn (vue)	1.3 MB	1.2 MB	+4.22%
⚡	Memory	mem server error-paths not-found (react)	277.7 KB	267.9 KB	+3.64%
⚡	Simulation	ssr control-flow unmatched 404 (react)	58.1 ms	56.3 ms	+3.14%

Tip

Investigate this regression by commenting @codspeedbot fix this regression on this PR, or directly use the CodSpeed MCP with your agent.

---

_{Comparing codex/fuse-static-route-nodes (f59c15d) with main (697ebb6)}

[nx-cloud]

Nx Cloud has identified a possible root cause for your failed CI:

We classified this failure as an environment state issue rather than a code change. The failing task (tanstack-solid-start-e2e-basic) is unrelated to the PR's touched project (@tanstack/router-core), and the root cause is a port conflict (EADDRINUSE :::37551) where another CI process occupied the port before the test server could start. A rerun of the pipeline should resolve this.

No code changes were suggested for this issue.

Trigger a rerun:

View detailed reasoning on Nx Cloud ↗

_{🎓 Learn more about Self-Healing CI on nx.dev}