SkateSpots/src/lib/lazyWithRetry.ts
SkateSpots 4e17852df3 fix(routes): self-healing lazy routes; document dev dep-cache crash
Symptom: in the long-running dev server some lazy routes (/settings, /stash,
/collections, /stats) hit the route error boundary ('This page slammed') while
others worked. Console: 'Failed to fetch dynamically imported module'; network:
504 for node_modules/.vite/deps/*.js. Vite's dep-optimizer cache had gone
missing after the server re-optimized on a lockfile change, leaving stale ?v=
hashes.

- Add lazyWithRetry: on a chunk-load failure, retry once, then do a single
  full reload per session (avoids reload loops); clears the flag on success
- Use it for all 53 lazy routes in AppRouter
- Document the dev dep-cache gotcha + fix in AGENTS.md
2026-09-26 20:36:14 +07:00

89 lines
3 KiB
TypeScript

import { lazy, type ComponentType, type LazyExoticComponent } from 'react';
/**
* `lazy()` with recovery from chunk-load failures.
*
* A lazy route's `import()` can fail transiently:
* • after a deploy, an already-open page still references chunk URLs that no
* longer exist on the server;
* • in dev, Vite's dependency optimizer can answer 504 ("Outdated Optimize
* Dep") for an optimized dependency after it re-optimized.
*
* Either way the import rejects and, with a plain `lazy()`, the route error
* boundary shows a dead "This page slammed" screen the user can do nothing with.
*
* Instead of failing hard we retry once, and if it still fails we do a single
* full reload per session (which fetches a fresh index + module graph). The
* session flag prevents a reload loop if the failure is genuinely persistent —
* then the error boundary is the correct last resort.
*/
const RELOAD_FLAG = 'skatespots:chunk-reload';
/**
* Pages take no props, so any props-compatible component type works here. Using
* `ComponentType<object>` (rather than `any`) keeps this type-safe while still
* accepting every page component in the router.
*/
type AnyComponent = ComponentType<object>;
function isChunkLoadError(error: unknown): boolean {
const message = error instanceof Error ? error.message : String(error);
return /Failed to fetch dynamically imported module|Importing a module script failed|error loading dynamically imported module|Outdated Optimize Dep|Failed to load module script/i.test(
message,
);
}
function hasReloadedThisSession(): boolean {
try {
return sessionStorage.getItem(RELOAD_FLAG) === '1';
} catch {
return false;
}
}
function markReloaded(): void {
try {
sessionStorage.setItem(RELOAD_FLAG, '1');
} catch {
/* sessionStorage unavailable — the retry below still runs */
}
}
function clearReloadFlag(): void {
try {
sessionStorage.removeItem(RELOAD_FLAG);
} catch {
/* ignore */
}
}
export function lazyWithRetry(
factory: () => Promise<{ default: AnyComponent }>,
): LazyExoticComponent<AnyComponent> {
return lazy(async () => {
try {
const module = await factory();
// A clean load means the module graph is healthy again; allow a future
// (unrelated) failure to trigger its own reload.
clearReloadFlag();
return module;
} catch (error) {
if (!isChunkLoadError(error)) throw error;
if (!hasReloadedThisSession()) {
markReloaded();
// Kick a full reload and suspend this import until the new document
// takes over. Never resolves — the navigation unloads the page.
window.location.reload();
return await new Promise<never>(() => undefined);
}
// Already reloaded once this session. The optimizer or CDN may have just
// needed a moment, so retry the import before showing the error boundary.
await new Promise((resolve) => setTimeout(resolve, 1000));
const module = await factory();
clearReloadFlag();
return module;
}
});
}