feat: add trailingSlash middleware

apps/scandic-redirect/netlify/functions/redirect.mts

@@ -22,8 +22,9 @@ export default async (req: Request) => {
               data.shift();
             }
             data.push(chunk.toString());
-
-            const re = new RegExp(`"${body.pathname}":"([^"]+)"`);
+            // Since we strip trailing slash (in the trailingSlash middleware) before entering this middleware,
+            // we need check matching paths both including and excluding trailing slash.
+            const re = new RegExp(`"${body.pathname}\/?":"([^"]+)"`);
 
             const match = data.join("").match(re);
             if (match?.[1]) {
@@ -46,10 +47,14 @@ export default async (req: Request) => {
       );
 
       if (redirectUrl) {
-        if (redirectUrl === body.pathname) {
+        // Make sure to exclude trailing slash in the redirectUrl to avoid an extra middleware roundtrip
+        const redirectUrlWithoutTrailingSlash = redirectUrl.endsWith("/")
+          ? redirectUrl.slice(0, -1)
+          : redirectUrl;
+        if (redirectUrlWithoutTrailingSlash === body.pathname) {
           return new Response("Not Found", { status: 404 });
         }
-        return new Response(redirectUrl);
+        return new Response(redirectUrlWithoutTrailingSlash);
       }
     }
     return new Response("Not Found", { status: 404 });

apps/scandic-web/middleware.ts

@@ -15,6 +15,7 @@ import * as handleAuth from "@/middlewares/handleAuth"
 import * as myPages from "@/middlewares/myPages"
 import * as redirect from "@/middlewares/redirect"
 import * as sasXScandic from "@/middlewares/sasXScandic"
+import * as trailingSlash from "@/middlewares/trailingSlash"
 import { getDefaultRequestHeaders } from "@/middlewares/utils"
 import * as webView from "@/middlewares/webView"
 import { findLang } from "@/utils/languages"
@@ -49,6 +50,7 @@ export const middleware: NextMiddleware = async (request, event) => {
 
   // Note that the order of middlewares is important since that is the order they are matched by.
   const middlewares = [
+    trailingSlash,
     currentWebLogin,
     currentWebLoginEmail,
     currentWebLogout,

apps/scandic-web/middlewares/trailingSlash.ts

@@ -0,0 +1,24 @@
+import { type NextMiddleware, NextResponse } from "next/server"
+
+import { getPublicNextURL } from "@/server/utils"
+
+import { getDefaultRequestHeaders } from "./utils"
+
+import type { MiddlewareMatcher } from "@/types/middleware"
+
+export const middleware: NextMiddleware = async (request) => {
+  const headers = getDefaultRequestHeaders(request)
+
+  const newUrl = new URL(
+    request.nextUrl.pathname.slice(0, -1),
+    getPublicNextURL(request)
+  )
+
+  return NextResponse.redirect(newUrl, {
+    headers,
+  })
+}
+
+export const matcher: MiddlewareMatcher = (request) => {
+  return request.nextUrl.pathname.endsWith("/")
+}