feat: improve structure and error handling

middleware.ts

@@ -1,16 +1,30 @@
-import { NextMiddleware } from "next/server"
+import { NextMiddleware, NextResponse } from "next/server"
 
+import { findLang } from "./constants/languages"
 import * as authRequired from "./middlewares/authRequired"
 import * as cmsContent from "./middlewares/cmsContent"
 import * as currentWebLogin from "./middlewares/currentWebLogin"
-import * as ensureLang from "./middlewares/ensureLang"
 import * as handleAuth from "./middlewares/handleAuth"
 import * as myPages from "./middlewares/myPages"
 import * as webView from "./middlewares/webView"
 
 export const middleware: NextMiddleware = async (request, event) => {
+  const lang = findLang(request.nextUrl.pathname)
+  if (!lang) {
+    // Lang is required for all our middleware.
+    // Without it we shortcircuit early.
+    // We use middleware-error route because notFound() requires a root layout
+    // which we do not want. We can move to that once all Current stuff is gone.
+    return NextResponse.rewrite(
+      new URL(`/${lang}/middleware-error/404`, request.nextUrl),
+      {
+        status: 404,
+        statusText: "Not found",
+      }
+    )
+  }
+
   const middlewares = [
-    ensureLang,
     currentWebLogin,
     authRequired,
     handleAuth,
@@ -19,13 +33,48 @@ export const middleware: NextMiddleware = async (request, event) => {
     cmsContent,
   ]
 
-  for (let i = 0; i < middlewares.length; ++i) {
-    const middleware = middlewares[i]
+  try {
+    for (let i = 0; i < middlewares.length; ++i) {
+      const middleware = middlewares[i]
 
-    if (middleware.matcher(request)) {
-      return await middleware.middleware(request, event)
+      if (middleware.matcher(request)) {
+        const result = await middleware.middleware(request, event)
+        const _continue = result?.headers.get("x-continue")
+        if (_continue) {
+          continue
+        }
+
+        // We use x-lang as either Akamai or Netlify use x-language as the users preferred language
+        result?.headers.set("x-lang", lang)
+        result?.headers.set("x-pathname", request.nextUrl.pathname)
+        result?.headers.set("x-url", request.nextUrl.href)
+        return result
+      }
     }
+  } catch (e) {
+    if (e instanceof NextResponse && e.status) {
+      return NextResponse.rewrite(
+        new URL(`/${lang}/middleware-error/${e.status}`, request.nextUrl),
+        {
+          status: e.status,
+          statusText: e.statusText,
+        }
+      )
+    }
+
+    console.error(`Error in middleware`)
+    console.error(e)
+    return NextResponse.rewrite(
+      new URL(`/${lang}/middleware-error/500`, request.nextUrl),
+      {
+        status: 500,
+        statusText: "Internal Server Error",
+      }
+    )
   }
+
+  // Follow through with normal App router rules.
+  return NextResponse.next()
 }
 
 // See "Matching Paths" below to learn more