Three mount points, so a render error costs the smallest part of the page it can.
The catalogue boundary is the one that earns its keep. The likeliest throw in this app is a component rendering data from the API, and the item grid renders the most of it per page — contained there, the header, cart badge, filters and footer all survive, so a customer can still navigate instead of being handed one dead page.
The modal boundary exists because the modal-route arrangement couples two independent trees. /account, /login and the rest render as modals over the storefront as a backdrop, so without a boundary between them a throw in Account blanks the storefront behind it and a throw in the storefront takes the open modal with it. One boundary separates them in both directions.
Every escape action is a hard navigation rather than a Link. This is worth stating because the obvious implementation is wrong: a boundary does not reset when the route changes, so a Link would change the URL and go on rendering the fallback, which reads as the app being permanently broken.
ErrorFallback changed too, outside this change's original scope and for a reason worth recording. antd's Result renders its title as a plain div with no heading semantics, so a page whose entire content is an error message offered a screen-reader user navigating by headings nothing at all to find. The title is now wrapped in Typography.Title. The tests assert a heading role and were right to; the component was what needed fixing, not the assertion.
DevThrow throws on ?boom=<scope> and is mounted only behind import.meta.env.DEV, so Rollup drops it from a production build. Checked in both directions rather than trusted: the dev server serves it, and a production bundle greps to zero occurrences of its marker. A gate that is silently always-off looks identical to one that works.
Verified: 87 end-to-end tests pass, 4 of them new — each boundary catches rather than blanking, the header survives a catalogue throw, the storefront survives a modal throw, and the report is observed reaching /api/client-errors on the wire rather than assumed. Build clean, lint 0 errors and 31 warnings.
Refs #62
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Three pieces, none of them mounted yet — the next change wires them into the tree.
ErrorBoundary is the only class component in the codebase, because getDerivedStateFromError and componentDidCatch have no hook equivalent. It knows nothing about antd and nothing about how reporting reaches the server: the fallback arrives as a render prop, which is what lets one boundary serve a full page, an inline region and a modal without knowing which it is.
ErrorFallback is the single place that decides whether a customer is shown a stack trace. The detail is gated on import.meta.env.DEV so a developer sees the throw immediately while a production bundle cannot render it at all — one decision in one file rather than the same judgement repeated at three mount points, where they would drift apart.
reportClientError posts to the endpoint added earlier and deliberately swallows its outcome. That is the one place in this feature where swallowing is correct: it runs inside componentDidCatch, so a reporter that rejected would throw from the very thing that exists to stop throws, with nothing left to catch it.
vite-env.d.ts was not in the plan and is needed. Nothing in this app had used import.meta.env before, so there was no ambient declaration for it and tsc rejected the DEV check outright. The standard one-line Vite reference fixes it, adds no dependency, and would have been needed by the next change regardless.
Verified: build clean, lint 0 errors and 31 warnings, unchanged from the branch baseline. No unit tests, because the frontend has no unit suite — that gap belongs to #72, and these components are covered end to end by the next change.
Refs #62
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
bermudalambandClaude Opus 5