Errors & Special Pages

Things go wrong; marko-run gives wrongness a home. Two special pages, defined only at the routes root:

+404.marko — served (with a real 404 status) when a request accepting HTML matches nothing.

+500.marko — served (status 500) when an uncaught error escapes from the request pipeline — a handler or middleware throwing before the page starts. A sharp distinction learned the hard way: once a page is streaming, the status line is long gone — errors mid-render are <try>’s territory (part three), not this page’s. Boundary inside the stream, +500 outside it.

Both are ordinary pages — the root layout wraps them, $global works. And for wrongness you choose, the context’s response helpers: context.redirect("/new-home") (relative paths resolved), context.back(fallback) (return-to-referer).

The site on the right is limping:

1. Visit /anything-wrong — the bare default 404. Create src/routes/+404.marko (tree unlocked): a friendly heading and a link home.
2. Visit /kaboom — its handler throws on purpose (peek at kaboom/+handler.js). Create +500.marko: “Something broke, it’s us not you.”
3. The old /store URL should live at /: fill in store/+handler.js with a Run.GET returning context.redirect("/") — click the stale link, land home, and check the network tab’s 30x if you’re curious.