added errorRedirect to middleware opts

runtime/src/server/middleware/get_page_handler.ts

@@ -11,7 +11,8 @@ import App from '@sapper/internal/App.svelte';
 
 export function get_page_handler(
 	manifest: Manifest,
-	session_getter: (req: Req, res: Res) => any
+	session_getter: (req: Req, res: Res) => any,
+	errorRedirect: any
 ) {
 	const get_build_info = dev
 		? () => JSON.parse(fs.readFileSync(path.join(build_dir, 'build.json'), 'utf-8'))
@@ -187,6 +188,21 @@ export function get_page_handler(
 			preload_error = { statusCode: 500, message: err };
 			preloaded = []; // appease TypeScript
 		}
+
+		// TODO validate location path against available routes
+		// TODO right now if location path doesn't exist, infinite redirects occur
+		try {
+			if (errorRedirect) {
+				const { errorStatusCode = 404, statusCode = 301, location = '/' } = errorRedirect;
+				const errStatusCode = (typeof errorStatusCode === 'number' || typeof errorStatusCode === 'string') ?
+					[Number(errorStatusCode)] : errorStatusCode.map(v => Number(v));
+				if (~errStatusCode.indexOf(status)) {
+					redirect = { statusCode: statusCode, location: location }
+				}
+			}
+		} catch (err) {
+			console.log(err)
+		}
 
 		try {
 			if (redirect) {

runtime/src/server/middleware/index.ts

@@ -8,9 +8,10 @@ import { lookup } from './mime';
 
 export default function middleware(opts: {
 	session?: (req: Req, res: Res) => any,
-	ignore?: any
+	ignore?: any,
+	errorRedirect?:any
 } = {}) {
-	const { session, ignore } = opts;
+	const { session, ignore, errorRedirect } = opts;
 
 	let emitted_basepath = false;
 
@@ -61,7 +62,7 @@ export default function middleware(opts: {
 
 		get_server_route_handler(manifest.server_routes),
 
-		get_page_handler(manifest, session || noop)
+		get_page_handler(manifest, session || noop, errorRedirect)
 	].filter(Boolean));
 }