fix(edge-runtime): match path with URI-encoded chars (#2873)

serhalp · mrstork · web-flow · commit 7fe6b3b63432 · 2025-05-05T23:00:16.000Z
Following the behaviour in vercel/next.js#78325, if a path matches a configured middleware matcher when URI-decoded, consider it a match. This doesn't seem ideal, but it aligns our behaviour with that of Next.js, and ensures that static asset matching behaviour aligns with edge middleware matching behaviour. Co-authored-by: Mateusz Bocian <mrstork@users.noreply.github.com>
diff --git a/edge-runtime/lib/routing.ts b/edge-runtime/lib/routing.ts
@@ -424,14 +424,24 @@ export interface MiddlewareMatcher {
   missing?: RouteHas[]
 }
 
+const decodeMaybeEncodedPath = (path: string): string => {
+  try {
+    return decodeURIComponent(path)
+  } catch {
+    return path
+  }
+}
+
 export function getMiddlewareRouteMatcher(matchers: MiddlewareMatcher[]): MiddlewareRouteMatch {
   return (
-    pathname: string | null | undefined,
+    unsafePathname: string | null | undefined,
     req: Pick<Request, 'headers' | 'url'>,
     query: Params,
   ) => {
+    const pathname = decodeMaybeEncodedPath(unsafePathname ?? '')
+
     for (const matcher of matchers) {
-      const routeMatch = new RegExp(matcher.regexp).exec(pathname!)
+      const routeMatch = new RegExp(matcher.regexp).exec(pathname)
       if (!routeMatch) {
         continue
       }
diff --git a/tests/e2e/edge-middleware.test.ts b/tests/e2e/edge-middleware.test.ts
@@ -233,6 +233,15 @@ test("requests with x-middleware-subrequest don't skip middleware (GHSA-f82v-jwr
   expect(response.headers.get('x-test-used-next-version')).toBe('15.2.2')
 })
 
+test('requests with different encoding than matcher match anyway', async ({
+  middlewareStaticAssetMatcher,
+}) => {
+  const response = await fetch(`${middlewareStaticAssetMatcher.url}/hello%2Fworld.txt`)
+
+  // middleware was not skipped
+  expect(await response.text()).toBe('hello from middleware')
+})
+
 test.describe('RSC cache poisoning', () => {
   test('Middleware rewrite', async ({ page, middleware }) => {
     const prefetchResponsePromise = new Promise<Response>((resolve) => {
diff --git a/tests/fixtures/middleware-og/package.json b/tests/fixtures/middleware-og/package.json
@@ -8,8 +8,6 @@
     "build": "next build"
   },
   "dependencies": {
-    "@aws-amplify/adapter-nextjs": "^1.0.18",
-    "aws-amplify": "^6.0.18",
     "next": "latest",
     "react": "18.2.0",
     "react-dom": "18.2.0"
diff --git a/tests/fixtures/middleware-static-asset-matcher/app/layout.js b/tests/fixtures/middleware-static-asset-matcher/app/layout.js
@@ -0,0 +1,12 @@
+export const metadata = {
+  title: 'Simple Next App',
+  description: 'Description for Simple Next App',
+}
+
+export default function RootLayout({ children }) {
+  return (
+    <html lang="en">
+      <body>{children}</body>
+    </html>
+  )
+}
diff --git a/tests/fixtures/middleware-static-asset-matcher/app/page.js b/tests/fixtures/middleware-static-asset-matcher/app/page.js
@@ -0,0 +1,7 @@
+export default function Home() {
+  return (
+    <main>
+      <h1>Home</h1>
+    </main>
+  )
+}
diff --git a/tests/fixtures/middleware-static-asset-matcher/middleware.ts b/tests/fixtures/middleware-static-asset-matcher/middleware.ts
@@ -0,0 +1,7 @@
+export default function middleware() {
+  return new Response('hello from middleware')
+}
+
+export const config = {
+  matcher: '/hello/world.txt',
+}
diff --git a/tests/fixtures/middleware-static-asset-matcher/next.config.js b/tests/fixtures/middleware-static-asset-matcher/next.config.js
@@ -0,0 +1,9 @@
+/** @type {import('next').NextConfig} */
+const nextConfig = {
+  output: 'standalone',
+  eslint: {
+    ignoreDuringBuilds: true,
+  },
+}
+
+module.exports = nextConfig
diff --git a/tests/fixtures/middleware-static-asset-matcher/package.json b/tests/fixtures/middleware-static-asset-matcher/package.json
@@ -0,0 +1,15 @@
+{
+  "name": "middleware",
+  "version": "0.1.0",
+  "private": true,
+  "scripts": {
+    "postinstall": "next build",
+    "dev": "next dev",
+    "build": "next build"
+  },
+  "dependencies": {
+    "next": "latest",
+    "react": "18.2.0",
+    "react-dom": "18.2.0"
+  }
+}
diff --git a/tests/fixtures/middleware-static-asset-matcher/public/hello/world.txt b/tests/fixtures/middleware-static-asset-matcher/public/hello/world.txt
@@ -0,0 +1 @@
+hello from a static asset
diff --git a/tests/utils/create-e2e-fixture.ts b/tests/utils/create-e2e-fixture.ts
@@ -333,10 +333,11 @@ export const fixtureFactories = {
   pnpm: () => createE2EFixture('pnpm', { packageManger: 'pnpm' }),
   bun: () => createE2EFixture('simple', { packageManger: 'bun' }),
   middleware: () => createE2EFixture('middleware'),
-  middlewareSubrequestVuln: () => createE2EFixture('middleware-subrequest-vuln'),
   middlewareI18nExcludedPaths: () => createE2EFixture('middleware-i18n-excluded-paths'),
   middlewareOg: () => createE2EFixture('middleware-og'),
   middlewarePages: () => createE2EFixture('middleware-pages'),
+  middlewareStaticAssetMatcher: () => createE2EFixture('middleware-static-asset-matcher'),
+  middlewareSubrequestVuln: () => createE2EFixture('middleware-subrequest-vuln'),
   pageRouter: () => createE2EFixture('page-router'),
   pageRouterBasePathI18n: () => createE2EFixture('page-router-base-path-i18n'),
   turborepo: () =>
