Function applyRewriteToState

packages/astro/src/core/rewrites/handler.ts:34–96

(
	state: FetchState,
	payload: RewritePayload,
	{ routeData, componentInstance, newUrl, pathname }: TryRewriteResult,
	{ mergeCookies = false }: { mergeCookies?: boolean } = {},
)

 * and `AstroMiddleware` (middleware `next(payload)`).
 */
export function applyRewriteToState(
	state: FetchState,
	payload: RewritePayload,
	{ routeData, componentInstance, newUrl, pathname }: TryRewriteResult,
	{ mergeCookies = false }: { mergeCookies?: boolean } = {},
): void {
	const pipeline = state.pipeline;
	const oldPathname = state.pathname;

	// Disallow SSR→prerender rewrites: the prerendered route becomes a
	// static HTML file during build and isn't available in the server
	// manifest. Allow i18n fallback routes as an exception.
	const isI18nFallback = routeData.fallbackRoutes && routeData.fallbackRoutes.length > 0;
	if (
		pipeline.manifest.serverLike &&
		!state.routeData!.prerender &&
		routeData.prerender &&
		!isI18nFallback
	) {
		throw new AstroError({
			...ForbiddenRewrite,
			message: ForbiddenRewrite.message(state.pathname, pathname, routeData.component),
			hint: ForbiddenRewrite.hint(routeData.component),
		});
	}

	state.routeData = routeData;
	state.componentInstance = componentInstance;
	if (payload instanceof Request) {
		state.request = payload;
	} else {
		state.request = copyRequest(
			newUrl,
			state.request,
			routeData.prerender,
			pipeline.logger,
			state.routeData!.route,
		);
	}
	state.url = createNormalizedUrl(state.request.url);
	if (mergeCookies) {
		const newCookies = new AstroCookies(state.request);
		if (state.cookies) {
			newCookies.merge(state.cookies);
		}
		state.cookies = newCookies;
	}
	state.params = getParams(routeData, pathname);
	state.pathname = pathname;
	state.isRewriting = true;
	state.status = 200;

	setOriginPathname(
		state.request,
		oldPathname,
		pipeline.manifest.trailingSlash,
		pipeline.manifest.buildFormat,
	);