codegraph/docs/design/framework-coverage.md

Framework & language coverage — what is done, what is left

Last verified: 2026-08-29 (Angular row: 2026-10-06; React Router row: 2026-10-07) against the build at that date. Re-verify with the queries in Checking this file is still true before trusting a row; this is a snapshot, not a live view.

This file exists to be read cold. It says, for every framework and language the README claims, which of the three pictures it can draw today and what is missing from the ones it cannot — so a fresh session can pick up the next piece without re-deriving the map.

---

The three axes

A framework's support is not one thing. Three separate facts in the graph unlock three different pictures, and a framework can have any subset:

Fact in the graph	Unlocks	Produced by
route nodes bound to a handler or component	the Entry points tab; an endpoint or page can be a Steps anchor	a framework resolver's extract()
navigates edges from the code that sends a user somewhere to the route it names	the Screens tab — without a single one, buildScreens returns routed: false and the tab stays hidden	a resolver's resolve() (calls) + a synthesizer (markup)
branch-guard rules for the language	the WHEN label on every arrow, in Steps, Screens and codegraph_explore's Flow section	src/graph/branch-guards.ts

The Screens picture is a pure function of the first two: any framework that produces route nodes and navigates edges lands on the tab, with no view code to write. That is why "add a router" is a small, self-contained job.

---

Routers — routes AND navigation (done)

Seven. Each reads a literal destination and leaves a computed one, a path no route serves, and a conditional whose arms disagree unresolved rather than guessed.

Router	Resolver	Markup synthesizer	Tests	Validated on
Expo Router	frameworks/expo-router.ts	expo-router-synthesizer.ts	expo-router.test.ts	—
Next.js	frameworks/nextjs.ts	next-router-synthesizer.ts	nextjs.test.ts	next-saas-starter
React Router	frameworks/react-router.ts	react-router-synthesizer.ts	react-router.test.ts	proshop (44 edges), proshop-v2 (28), react-redux-realworld (22), react-boilerplate (styled(Link)), takenote (v5 <Redirect>), bulletproof-react (nested children, lazy routes, paths.x.path constants through an app's own tsconfig alias: 0 → 9 named, linked routes), and its paths.x.getHref(id) links and navigate(paths.x.getHref()) calls (0 → 11 navigates). Route tables another file hands the router (tableRoutes in frameworks/react.ts, trap 13): the ASP.NET Core React template's AppRoutes.map(… <Route {...rest}>) on jasontaylordev/CleanArchitecture's ClientApp-React (0 → 6 routes, 11 navigates), replaysMike/Binner (0 → 46, 87), GavinLonDigital/RankingApp, GarrettHays/PaydirtPickem, charlessolar/eShopOnContainersDDD; useRoutes(routes) from another file and [...sessionRoutes] on uilibrary/matx-react (0 → 7, 16); codedthemes' createBrowserRouter([MainRoutes, LoginRoutes]) on berry and mantis (9 and 8 routes, no navigation they can resolve); a table .mapped inside <Route path="/dashboard"> on RADeveloping/chickadeeinvest; useRoutes([...]) in place on minimal-ui-kit/material-kit-react (0 → 7, bound through lazy(() => import(…)) to each page). JSX index routes and layouts (trap 14): proshop-v2's createRoutesFromElements (/ is HomeScreen inside App, not App; 30 layout edges, the path='' guards included; Screens 30 → 74 transitions, the guards' redirects drawn from the screens they guard), chickadeeinvest's table inside <Route element={<DashboardLayout/>}> (its 4 routes get the layout), React Router 6.29's own examples and tests, refine's 281 examples (one / per app, 191 layout edges, 21 new navigations), crwn-clothing, the vanlife course app, volun-mern (105 layout edges, six levels deep), spotify/vispana, react_persist_login, chushi (path={"agents"}: 2 → 6 routes), hathor-explorer (path="" at the root), cboard, react-router-auth-v6: 578 of 581 new layout edges name a component of an enclosing <Route> (vanlife's 3 inherit a default-import resolution bug that already misbinds its pages), 27 of 27 new navigations precise, no navigation lost, 16 control repos byte-identical. Lazy route modules that are barrels (exportedComponent in frameworks/react.ts): luci-go's milo/ui (export * from './x' index files and export { X as Component } clauses: 0 → 51 lazy routes linked; the other 40 load a file under src/build/, which the default ignore skips, export only a loader or a handle, or pick a named export in an async lazy), Medusa's admin dashboard (all 193 route-map modules resolve through its export { X as Component } from barrels, but its routes are not extracted: getRouteMap() returns the table), four more apps (9 routes), 16 control repos byte-identical
TanStack Router	frameworks/tanstack-router.ts	tanstack-router-synthesizer.ts	tanstack-router.test.ts	TanStack examples, fastapi-template frontend
Vue Router / Nuxt	frameworks/vue-router.ts (Nuxt file routes: nuxtResolver in frameworks/vue.ts)	vue-router-synthesizer.ts	vue-router.test.ts	vue-realworld (23 edges); vue-element-admin (62 routes), vue-admin-template (14), vben (192), halo console (34) — named tables, module files, children + layouts; Nuxt: mealie, elk, nuxt/movies
SvelteKit	frameworks/sveltekit-router.ts	sveltekit-synthesizer.ts	sveltekit-router.test.ts, sveltekit-route-names.test.ts	sveltekit-realworld (31 edges); shadcn-svelte and skeleton ((group) layouts: 13 and 23 edges), svelte.dev (74), kit's test apps (47)
Angular	frameworks/angular-router.ts	angular-template-synthesizer.ts	angular-router.test.ts	angular-realworld (31 edges, 18 renders, 32 bindings), Ghostfolio (189 edges, 170 renders, 215 bindings), ngx-admin (routes and renders; its menus are config; 13 bindings), CleanArchitecture's src/Web/ClientApp (signals; 12 bindings), angular-spotify (Nx libs behind barrels: 14 routes), jira-clone (class-constant paths, mount-only redirects), jhipster (60), ionic-conference (18), Angular-JumpStart (18)

Shared machinery all seven use, in frameworks/expo-router.ts: RouteTable / RootedRouteTable, routesForFile, addRouteTo, matchRoute, appRootFor, parseHrefExpression, readHrefViaLocal, nthArgumentText, readStringAt, toHref. Plus pageForHref in frameworks/nextjs.ts (framework-agnostic despite where it lives) and the object-literal walker in frameworks/object-literal.ts.

Angular is the one whose markup is not indexed: a component's template is a templateUrl file (or an inline template: string) read at synthesis time, which also yields the component tree (<app-foo> by element selector) — the edge a navigation in a child component rides to its screen. A routerLink: field written in a component's class (a tab bar's or a menu's config, bound in a loop elsewhere) counts as a link from that component. An event binding ((click)="save()") is a calls edge from the component to its own method carrying metadata.trigger, which Steps uses in place of reading a trigger at the edge's line (the binding is in the template, not the source there). A property binding, an interpolation, a structural directive or a control-flow block that calls one of the component's own members ([name]="icon()", {{ label() }}, *matRowDef="let row; columns: displayedColumns()", @if (loading()), @let total = price();) is a calls edge too (angular-binding, the binding as via), with no trigger: it runs when the template renders, so Steps folds it into the screen rather than drawing a handler the user fires — a trigger there drew computed signals as user actions. A member read without a call counts only when it is method-kind: a getter is called, a method handed to a child ([displayWith]="displayFn", trackBy: trackById) is a references edge with fnRef, and a field a call filled (days = Array.from(…)) a plain references. A property read ([value]="title") links nothing, as in TypeScript, which records no property reads either; on angular-realworld, ngx-admin, Ghostfolio and CleanArchitecture it would have added four times the edges and taken nothing off the Dead code list, which never asks about properties. A pipe, an object key, a microsyntax key (of, trackBy:, index), a template's own names (let item, as user, #ref, @let x, let-row) and a commented-out binding link nothing. A route with children is a layout: its component carries a references edge marked layout: true from each screen nested in it, and routeLayouts in route-roots.ts gives Screens every screen a layout serves. Known limits: a route with a custom matcher has no static address, a relative navigation (relativeTo) is left unresolved, an edit to a template file alone is picked up at the next sync of any source file (templates are not watched), a member a component inherits from a base class is not linked from its template, and a template's local hides a same-named member for the rest of the template rather than only inside its block.

---

What is left

Ordered by cost-to-value. Each row says what is missing, not merely that something is.

1. Astro — the last web framework with routes but no navigation

Has: src/pages/ file routes (.astro pages + .ts endpoints, [param]/[...rest]), in frameworks/astro.ts. Missing: navigates edges. Astro is an MPA — navigation is a plain <a href="/about">, plus Astro.redirect('/x') in frontmatter and redirect entries in astro.config. Size: smallest job on this list. sveltekit-synthesizer.ts's svelteKitLinkEdges is the same pass over the same tag against a different table; the resolver half is one Astro.redirect reader. Validate on: any withastro/astro example, or the Astro docs site.

2. Server-rendered frameworks — a redirect is a transition, not just a response

Fourteen frameworks have route nodes and no navigation: Django, Flask, FastAPI, Express, NestJS, Laravel, Drupal, Rails, Spring, Play, Gin/chi/gorilla, Axum/actix/Rocket, ASP.NET, Vapor.

Be precise about what is missing. redirect_to, HttpResponseRedirect, res.redirect, PHP's redirect() are already recognised as response effects (ui-server/api/effects.ts), so they draw as a box in the Steps picture. What is missing is the edge to the page they name — so two pages never connect on the Screens tab.

For a pure API this is correct and nothing should change: an endpoint is not a screen. It matters for the server-rendered half, where a classic MVC app gets no Screens picture at all today:

Framework	The destination to read	Why it is harder than a client router
Rails	redirect_to :dashboard, redirect_to users_path	destinations are named helpers (*_path/*_url) generated from routes.rb, not literals
Django	redirect('profile'), reverse('profile')	same — a route name, like Vue's { name }, which vue-router.ts already shows how to index
Laravel	redirect()->route('home'), ->view()	route names again
Spring	"redirect:/x", RedirectView	a literal inside a string return value
ASP.NET	RedirectToAction("Index", "Home")	controller + action pair, not a path — needs the route table's reverse mapping
Flask	redirect(url_for('profile'))	nested call; the name is url_for's argument

The Vue name-index (VueAppRoutes.byName) is the closest existing precedent for all of these.

3. Native UI — no route nodes at all

Platform	Routes would come from	Navigation would come from
SwiftUI	NavigationStack(path:), .navigationDestination(for:)	NavigationLink(value:), path.append(…)
Jetpack Compose	NavHost { composable("route") { … } }	navController.navigate("route")
Flutter / Dart	MaterialApp(routes: {…}), GoRouter([...])	Navigator.push, context.go('/x')

All three are named in scripts/try-repo.sh's presets as not modelled (icecubes, nowinandroid). Compose and go_router are the most tractable — both name routes with string literals, which is the same shape every router above reads.

4. ArkTS / HarmonyOS — closest to done of anything here

Has: the hard half already. arkuiRouterEdges in callback-synthesizer.ts resolves router.pushUrl('/pages/Detail') to the target page struct. Missing: it emits a calls edge and no route node, so it never reaches the Screens tab. Size: an edge-kind change plus route nodes for pages/ entries — no new analysis.

---

Languages

All ~30 languages in the README have full structural extraction; nothing is outstanding on that axis. The gap that is language-shaped is the WHEN label.

Guard rules exist (RULES_BY_LANGUAGE in src/graph/branch-guards.ts) for: TypeScript, TSX, JavaScript, JSX, Swift, Python, Java, Kotlin, C#, Go, C, C++, Objective-C.

(Metal and CUDA parse as C++ and ArkTS does not parse as TypeScript, so the first two inherit the C rules and the third has none.)

No rules — boxes draw, arrows carry no condition, and no arguments or trigger labels are read: PHP, Ruby, Rust, Scala, Dart, Erlang, Lua, Luau, R, Solidity, COBOL, CFML, VB.NET, Nix, Terraform, Pascal/Delphi, Liquid, Razor, Twig, ArkTS, and the .svelte / .vue / .astro template languages.

A language with no rules yields nothing, never a wrong label — that is the design, so an absent row here is a missing feature, not a bug.

Ruby and Rust sting most: both have server frameworks in the README's table (Rails, Axum/actix/Rocket), so their Steps pictures draw responses and database calls with no conditions on any arrow. scripts/try-repo.sh's bookstack preset says exactly this for PHP.

---

Traps a new router will hit

Each of these cost real debugging time; they are not hypothetical.

1. A references edge cannot cross a language family. applyLanguageGate in name-matcher.ts filters references candidates to sameLanguageFamily, so a .js router config can never name a .vue component — it silently binds to a same-named .js function in a store instead. Bind a route to its component with calls, which route-roots.ts reads as "the page a screen file exports".
2. One address, one screen. A layout and the index route beside it resolve to the same path (+layout.svelte vs +page.svelte, dashboard.route.tsx vs dashboard.index.tsx, _auth.invoices.tsx vs _auth.invoices.index.tsx). Emitting both puts one address on the map twice. Decide per file — the sibling is not visible at extraction time.
3. The route table must be per app. A repository with two apps has two / and two /login; a global table hands the address to whichever was indexed first. Measured at 82% of navigations pointing into a different app on a 477-app monorepo before RootedRouteTable / routesForFile. The roots list decides only whether to resolve.
4. Read fields from the object, not from a window around one. A Vue route's name is written above its path, so a text window handed every entry its predecessor's name — silently, for every route in the file. Use frameworks/object-literal.ts. A lazy view binds by the FILE it imports, never by the import's last segment: vue-element-admin's views are all …/index.vue. Nuxt's pages/ convention belongs to a Nuxt app only — a plain Vue app's pages/ folder (halo's console) holds components a router config names.
5. A receiver is required for a generic verb. push and replace are two of the most common method names in JavaScript; claiming a bare one puts every paths.push('/tmp/x') one string-match away from a route.
6. One component can be several screens. A listing rendered at /, /search/:keyword and /page/:n is one component and three addresses; screenOfComponent maps a component to every route it serves, and collapseSharedChrome counts distinct screen COMPONENTS, not addresses — counting addresses collapsed one component's four routes into an origin and took the navigation away from all of them.
7. A destination can name several routes. parseHrefExpression returns one HrefLiteral carrying alternates, and destinationsForHref turns it into one { node, href } per arm. A synthesizer emits an edge apiece; a resolver puts the first on the ResolvedRef and the rest in alsoTargets, which createEdges fans out — the reference still resolves ONCE, so the pipeline's cleanup and counts are untouched. Label each edge with the arm that named it, or an edge points at one route while naming another's path.
8. Read markup with the same reader as calls. A synthesizer that peeks at the first character of to={…} misses every conditional and template the push(…) path handles. Use parseHrefExpression on the balanced brace contents.
9. A condition is read the same way for markup as for a call. The Screens walk used to skip the when on any synthesized edge, so every <Link to> read as always while the push() beside it carried its guard. The reader works fine at a markup site — a JSX {step1 ? <Link/> : …} is a ternary like any other — and the site's own verb (link, a) is the honest label; return belongs only to an edge whose destination came from elsewhere, which is what registeredAt pointing at another line means.
10. A route is not always a screen. The Screens picture is about navigation, so it draws only routes named by a path; a route named with the HTTP method that reaches it is an endpoint and belongs on Entry points. Nuxt is the exception that names an endpoint like a page (/api/users from server/api/), and is excluded by file path.
11. Detection runs before any file is indexed. declaredDependencies caches per file-count for exactly this reason — an earlier version cached the empty pre-index answer and every framework whose dependency lived one directory down stayed undetected.
12. An app's manifest can sit three or more levels down. An ASP.NET solution keeps its single-page app in src/Web/ClientApp/, and prometheus keeps its React apps in web/ui/mantine-ui/ under a workspace root at web/ui/ that declares only tooling. declaredDependencies reads the root and the first two levels, then gives the slots left to the directories above JS/TS code, shallowest first. Read only two levels deep, Angular Router never ran on jasontaylordev/CleanArchitecture, and every template-bound handler there was listed as dead code. A new detector that gates on a dependency should ask dependsOn, not read a package.json itself, so it sees the same manifests every other detector does.
13. A route table can be named only by another file. The ASP.NET Core React template keeps its routes in AppRoutes.js, a file that never names the router, and renders them from App.js with AppRoutes.map(({ element, ...rest }) => <Route {...rest} element={element} />); codedthemes' admin kits put one route object per file and list them in createBrowserRouter([MainRoutes, LoginRoutes]). Read on its own, such a file cannot be told from a menu's { path, element } list, and per-file extraction cannot see the file that hands it over, nor run again when that file changes. So React keeps those routes in the cross-file pass (FrameworkResolver.crossFileNodes, reconciled in runPostExtract on every index and sync, removals included): it starts from the files that import React Router, takes only a useRoutes / create*Router argument or a .map whose callback renders a <Route> from the item's own fields ({...route}, {...rest}, path={route.path} — never path={r.layout + r.path}), follows the import to the table and the tables it names in turn, and owns its routes by id (…:table:<path>). One limit it shares with every router: a table rendered by a component that is itself mounted under another file's <Route path="/admin/*"> reads as if at the root. A sync that changes such a route resolves the calls it can answer again (16), as for any other route.
14. An index route is at its parent's address, so it needs that address written down. <Route index element={<Home />} /> inside <Route path="/" element={<Layout />}> is the page at /, and Layout is the layout of every route nested in it (trap 2: emitting Layout as a second / page drew the app's chrome as the home screen and its header's links from / alone). A <Route path> with no element only groups its children and yields its address the same way. But a <Routes> inside a component is mounted wherever another file's <Route path="shop/*" element={<Shop />}> puts it: read as /, crwn-clothing's Shop index made a second home page. So an index route at the top of a <Routes> is read only inside the router itself (createRoutesFromElements(…), <BrowserRouter>), and one under a path the file does not spell out (path={paths.agents}) not at all; path={"agents"} is spelled out. Reading what an element renders has three traps of its own: skip elements written in an attribute unless the attribute hands over a page (component, element, page) — <Suspense fallback={<Loader />}> bound fifteen routes of one app to the spinner; trim the line break Prettier writes after element={, which hid every long element; and read <Outlet /> as rendering nothing of its own. Version 5's <Route path="" component={NotFound} /> is a catch-all, not the page at its parent's address. A table written in another file and mapped inside a <Route element> gets no layout edge: the layout's name would be looked up in the table's file, and the cross-file pass compares only route names, so a changed layout would never reach the table's routes.
15. resolve() sees only references written in the framework's own languages (getResolvingFrameworks): Express's logger middleware rule once took etcd's Go *zap.Logger result types for a method. A navigation written in markup (.svelte, .vue) needs that language in languages. A resolver that reads a language it extracts nothing from lists it in resolveLanguages instead — Svelte's $lib/… imports in .ts route modules, ASP.NET's Razor @model — because widening languages also runs extract() on those files. claimsReference() is still asked of every detected framework.
16. A navigation call waits for a route, not for a name. A call indexed before its route existed is parked as failed (or bound to a catch-all, a parameter route, the other arm of a conditional), and sync revisits a failed reference only by matching its last name segment against the names the synced files define — never push or navigate. Set the resolver's navigation: tails, the method names its calls end in, and scope, the apps whose calls one of its routes can answer (its own app's table, or every file for a table the whole project shares). A sync that adds, removes or renames a route — a cross-file table route included — then resolves those calls again, failed or not; without it the synced index keeps an answer a full index does not have. sync-navigation-retry.test.ts runs all seven routers through it, and asserts each router's calls end in a declared tail.

---

The bar for calling one done

Per CLAUDE.md's validation methodology, and what was actually done for the four routers added on 2026-08-29:

1. A real repo, not only a fixture. Every defect in this session's work was caught by a real repository and none by the fixture written first.
2. Recall against ground truth. grep every navigation site in the source and account for each one: resolved, or correctly unresolved because it is computed.
3. Precision, site by site. For every synthesized edge, read the line its registeredAt names and confirm the tag or call there names that destination. Target: zero false positives.
4. Controls re-indexed. Node, edge, route and navigates counts on repos the change should not touch — a change to shared machinery is not done until they are byte-identical or the difference is explained.
5. Full suite green, and a CHANGELOG entry in the user-facing voice.

---

Checking this file is still true

# Which frameworks emit navigates edges
grep -rn "edgeKind: 'navigates'\|kind: 'navigates'" src --include="*.ts" | sed 's|:.*||' | sort -u

# Which languages have branch-guard rules
sed -n "/^const RULES_BY_LANGUAGE/,/^\]);/p" src/graph/branch-guards.ts

# Whether a repo's Screens tab is on, and how many transitions it has
scripts/try-repo.sh <preset>        # prints the navigation count and says which tab is on

-- In a repo's .codegraph/codegraph.db
select count(*) from edges where kind='navigates';
select name, file_path from nodes where kind='route' order by name;   -- duplicates = a layout drawn as a screen