Remix V2 Routing Review

Remix v2 Routing Code Review

Loaded by review-remix-v2 (umbrella) to flag routing anti-patterns in app/routes/ modules. See remix-v2-routing for canonical patterns.

Quick Reference

Scope

This skill flags issues in:

• Files under app/routes/ (filenames, exports, imports, JSX shape)
• app/root.tsx (document shell, root <Outlet />)
• remix.config.js (entries that change route discovery: routes(), ignoredRouteFiles, @remix-run/v1-route-convention)
• Any module that links to a resource route (<Link> usage)

Out of scope: loader/action data contracts (covered by remix-v2-data-flow-review), form behavior (remix-v2-forms-review), meta/headers (remix-v2-meta-sessions-review).

Review Checklist

• Index routes named _index.tsx, not index.tsx
• Pathless layouts use single underscore (_auth.tsx), not double (__auth/)
• Dotted child routes (users.profile.tsx) have a parent module or use trailing underscore (users_.profile.tsx)
• Parent route modules render <Outlet />
• Splat segments read params["*"], never params.splat / params.rest
• Literal dots/special chars escaped with brackets (sitemap[.]xml.tsx)
• Resource routes have no default export
• <Link> to a resource route uses reloadDocument (or is a plain <a>)
• Imports come from @remix-run/react, not react-router-dom
• Non-route files (CSS, helpers, tests) live in a folder with route.tsx, or are listed in ignoredRouteFiles
• Trailing-underscore opt-outs only used when a parent layout actually exists to escape
• Optional segments ($lang) narrow params.lang in the loader (see references/route-files.md)

Valid Patterns (Do NOT Flag)

• Resource route with no default export — this is the convention that makes it a resource route. Never flag.
• Any _-prefixed pathless layout file without <Outlet /> when the module is intentionally a wrapper that renders fixed UI only. Confirm by checking children — if no *.{segment}.tsx siblings exist, the wrapper-only shape is intentional.
• Files prefixed with _ that don't appear in any URL — pathless layouts and _index are supposed to be hidden from the URL.
• @remix-run/v1-route-convention wired up in remix.config.js — legitimate migration adapter, not a smell on its own. Only flag if v1-style files appear without the adapter installed.
• useLoaderData<typeof loader>() — type annotation, not assertion.
• Splat route accessing params["*"] with bracket syntax — that is the only correct access pattern.
• Folder app/routes/dashboard/ with route.tsx plus sibling .server.ts, .css, component files — co-location is the documented pattern.
• Trailing underscore (concerts_.mine.tsx) when a sibling concerts.tsx layout exists and this URL intentionally skips it.

Context-Sensitive Rules

Only flag these issues when the specific context applies:

Hard gates (before writing findings)

Run these in order. Do not draft user-facing findings until every gate passes for the batch you are about to report.

1. Location evidence — Pass: Each issue lists a repo path (file under app/routes/ or remix.config.js) and either a line range or a short verbatim quote from the file you read. Filename-only smells must quote the literal filename.

2. Exemption check — Pass: For each issue, state in one line why it is not covered by Valid Patterns (Do NOT Flag). Resource-route flags require explicit evidence of a default export or a <Link> without reloadDocument.

3. Version check — Pass: Confirm the project is Remix v2 (check package.json for @remix-run/react ^2, or presence of v2 flat-routes filenames elsewhere in app/routes/). If @remix-run/v1-route-convention is wired in remix.config.js, v1 filenames (__auth/, index.tsx) are intentional — do not flag them as smells.

4. Protocol — Pass: Complete the Pre-Report Verification Checklist in review-verification-protocol for this review.

When to Load References

• Reviewing filenames under app/routes/ → references/route-files.md
• Reviewing parent modules and shared chrome → references/layouts-outlets.md
• Reviewing a module that returns non-HTML, or any <Link> to such a module → references/resource-routes.md
• Reviewing imports or filenames that look like v1 → references/v1-holdovers.md
• Reviewing app/root.tsx (document shell, <Meta />/<Links />/<Scripts />/<ScrollRestoration />, <LiveReload /> on Vite vs Classic Compiler, root ErrorBoundary) → references/root-shell.md

Review Questions

1. Does every parent route render <Outlet />, or is it a deliberate wrapper-only?
2. Do filenames match the v2 grammar (single _ for pathless, _index for index, [...] for escapes)?
3. Are resource routes free of default exports, and do all <Link>s to them use reloadDocument?
4. Are all router imports from @remix-run/react (and server helpers from @remix-run/node)?
5. If v1 filenames exist, is @remix-run/v1-route-convention wired up — or are they accidental?

Additional Documentation

• Route file naming smells: references/route-files.md — index.tsx, __double folders, wrong escape syntax, dot/underscore confusion, non-route files under app/routes/.
• Layouts and outlets: references/layouts-outlets.md — pathless layout misuse, missing <Outlet />, orphan dotted children, duplicated layout logic.
• Resource routes: references/resource-routes.md — accidental default export, <Link> without reloadDocument, splat params["*"] access.
• v1 holdovers: references/v1-holdovers.md — react-router-dom imports, __auth folders, @remix-run/v1-route-convention as a deliberate-vs-accidental tell.