astro/dist/core/routing/redirect-page.js

Astro is a modern site builder with web best practices, performance, and DX front-of-mind.

import { getEnvironment } from "../environment/index.js";
import { FetchState } from "../fetch/fetch-state.js";
import { handleMiddleware } from "../middleware/astro-middleware.js";
import { handlePages } from "../pages/handler.js";
import { isRoute3xx } from "./internal/route-errors.js";
import { getRouteTable } from "./route-table.js";
/** The delay Astro's built-in redirect page uses for `status`. */
export function redirectDelayFor(status) {
	return status === 302 ? 2 : 0;
}
/**
* Renders the project's `src/pages/3xx.astro` as the body of a redirect,
* returning its HTML.
*
* Returns `undefined` when the project has no `3xx.astro`, or when rendering it
* fails — the caller falls back to Astro's built-in redirect page so a broken
* custom page degrades to a working redirect instead of failing the build.
*
* Middleware is skipped: it already ran for the request that produced the
* redirect, and re-running it around a template render would let a middleware
* that redirects recurse.
*/
export async function renderRedirectPage(manifest, request, props) {
	const route = getRouteTable(manifest).routes.find((candidate) => isRoute3xx(candidate.route));
	if (!route) {
		return undefined;
	}
	const state = new FetchState(manifest, request);
	try {
		state.skipMiddleware = true;
		state.routeData = route;
		state.pathname = route.route;
		// The page renders as an ordinary 200; the caller re-applies the redirect
		// status to the response it builds around this HTML.
		state.status = 200;
		state.componentInstance = await getEnvironment(manifest).getComponentByRoute(manifest, route);
		state.initialProps = { ...props };
		const response = await handleMiddleware(state, handlePages);
		return await response.text();
	} catch (err) {
		state.logger.error("redirects", `Failed to render \`src/pages/3xx.astro\` for the redirect from \`${props.from}\` to \`${props.to}\`. Falling back to the built-in redirect page.\n${err instanceof Error ? err.stack ?? err.message : String(err)}`);
		return undefined;
	} finally {
		// Swallow a rejecting finalizer rather than let it replace the `undefined`
		// returned above: the caller reads that as "fall back to the built-in
		// redirect page", and a failure to clean up should not turn a broken
		// custom page into a failed build.
		try {
			const finalize = state.finalizeAll();
			if (finalize) await finalize;
		} catch (err) {
			state.logger.error("redirects", `Failed to finalize the \`src/pages/3xx.astro\` render for the redirect from \`${props.from}\` to \`${props.to}\`.\n${err instanceof Error ? err.stack ?? err.message : String(err)}`);
		}
	}
}