fix(react): a JSX tag imported from the project renders what its module exports

[colbymchenry]

Summary

The JSX render pass (jsxChild in src/resolution/callback-synthesizer.ts) matched a tag by name and used the file's imports only to break ties. So when a tag is imported through an index that forwards another module's component, the index declares no candidate and the name picks one elsewhere: outline's Sidebar/index.ts is import Sidebar from "./App"; export default Sidebar, and <Sidebar> rendered Aside.tsx's styled Sidebar instead of the AppSidebar that App.tsx exports as observer(AppSidebar).

A tag imported from a module of the project now renders what that module exports under the imported name. The export is read by exportedComponent in frameworks/react.ts, the reader lazy routes already use (now exported), so the following are covered:

• Forwarding through an index or barrel: import X from './App'; export default X, export { X } of an import, export { default } from, export * (with JavaScript's ambiguity rule), and renamed default imports.
• Wrappers: observer(AppSidebar), React.memo(StaticCanvas, areEqual), React.forwardRef<…>(Button).
• Two new shared rules, which lazy routes get too:
  • A const holding another binding is that binding. outline's Avatar/index.ts is const Avatar = AvatarWithHoverCard; export { Avatar }, and signoz has export const TanStackRowCell = TanStackRowCellMemo as typeof TanStackRowCellInner. If the binding leads nowhere, the value stays the export. A let isn't followed, because it may be reassigned. The withAuth(Page) guard from fix(react-router): a lazy route follows a barrel that re-exports an import #2558 is unchanged.
  • A memo wrapper's component node is the component it wraps. mastodon's const MemoizedBlurhash = memo(Blurhash); export { MemoizedBlurhash as Blurhash } and excalidraw's export const Excalidraw = React.memo(ExcalidrawBase, areEqual) used to land on a component node with no body and no outgoing edges, so render flows dead-ended there.
• Decline: when the import resolves to a module whose export is no component node (export default ({ url }) => …), the tag links nothing. Before, it linked a namesake elsewhere. A namesake the module itself declares still links; that covers a CommonJS module.exports = Card.
• Sync: synthesis inputs now include every file a project-imported tag is read through. So codegraph sync and the watcher redraw the tag when only the forwarding index, or the module behind it, changes. The new sync tests compare against a fresh index.

One existing expectation changed. In react-router-lazy-barrel.test.ts, the /builders route's module is export const Component = BuilderListPage, and the route now links BuilderListPage (the function with the markup) instead of the alias constant, which has no edges.

Scope

• Package imports (the other half of the original task) landed separately in fix(react,vue): a tag imported from a package renders no project namesake #2475.
• fix(react): a JSX tag renders what the file imports under that name #2451 (open) adds forwarding to the general import resolver (findExportedSymbol / defaultExportBindingNode). This PR doesn't touch the import resolver; it reuses the lazy-route reader inside the JSX pass.

Validation

Fresh-index A/B. Main d0bb9be5 against this branch: fresh indexes of 13 repos, dumped with scripts/dump-graph.mjs and compared by natural keys. Every changed edge was graded by a TypeScript-checker oracle. The oracle binds the tag with the checker, follows import aliases, and follows a value that holds another binding to its declaration. A target is right if it is that declaration or the component its wrapper hands on. A tag whose name binds no component in the project is right with no edge.

repo	changed tag sites	none→right	wrong→right	right→right¹	wrong→none²
outline	386	175	158		53
bulletproof-react	255	88	167
mastodon	101	57	25	15	4
signoz	61	56³	5
excalidraw	55	34	5⁴	16⁴
bigbluebutton	24	16	8
mantis	4	2	2
berry, matx, minimal-kit	1 each	2	1
total	889	430	371	31	57

• Controls: proshop_mern, next-saas-starter and create-t3-turbo are byte-identical.
• Recall: no tag loses a correct edge (no right→wrong or right→none).
• Dead ends: no tag moves from a node with outgoing edges to one without.

¹ The tag moved from a bodyless memo wrapper to the component it wraps: <Excalidraw> → ExcalidrawBase, mastodon <ShortNumber> → ShortNumberRenderer.
² The decline: outline's email Header/Footer/Diff tags, whose modules default-export an unnamed arrow and used to link the app's namesakes, and mastodon's 4 connect()-wrapped containers.
³ Includes one generic tag, <TanStackTable<T, TItemKey>>, that the oracle can't locate. I checked it by hand.
⁴ Includes two sites in examples/with-nextjs, graded with that example's own tsconfig. The <Excalidraw> one is the same unwrap; the checker can't resolve the package import there.

Tests:

• New: 9 tag cases in jsx-child-disambiguation.test.ts and a lazy-route memo case in react-router-lazy-barrel.test.ts. One tag case pins that a let alias is not followed, since it may be reassigned.
• New file sync-jsx-import-forwarding.test.ts: the index rewired (full and scoped sync), the index switching to a value alias, and the module behind the index rewrapped. Each case compares the synced graph with a fresh index.
• Mutation checks: the alias tests fail without the alias hop, and the Blurhash tag and route tests fail without the memo unwrap.
• 26 related suites: 596/596 pass.
• Full suite on Windows: 6,687 passed. 18 tests in 9 unrelated files failed under load: 16 timeouts and 2 EBUSY daemon teardowns, in the daemon, MCP freshness, sync and worktree suites. All 9 files pass when rerun serially (155/155).

Timing: I compared main and this branch over 5 interleaved rounds per arm, on a shared box, and took medians.

repo	full index wall	jsxEdges pass wall
bulletproof-react	+5.8% (+0.18 s)	+53 ms
excalidraw	−2.3%	+95 ms
outline	+0.4%	+68 ms
mastodon	+0.1%	+56 ms
signoz	+1.9%	+144 ms

A CPU profile of the pass puts the added time in comment-stripping the modules that tags import from (about 125 ms on signoz) and in resolving those imports' paths. I didn't add a cross-pass cache of module text: it would pin text the resolver's LRU file cache evicts on purpose.

🤖 Generated with Claude Code