Next.js: ignore prefetch request for /logout middleware route

src/nextjs/index.test.ts

@@ -122,7 +122,7 @@ describe('middleware', () => {
     },
   ]);
 
-  describe('logout', () => {
+  describe('login', () => {
     it('should redirect to Fief authentication URL', async () => {
       const request = new NextRequest('http://localhost:3000/login');
       const response = await middleware(request);
@@ -156,6 +156,15 @@ describe('middleware', () => {
   });
 
   describe('logout', () => {
+    it('should do nothing and just return empty response on prefetch', async () => {
+      const request = new NextRequest('http://localhost:3000/logout', { headers: { 'X-Middleware-Prefetch': '1' } });
+      const response = await middleware(request);
+
+      expect(response.status).toBe(204);
+
+      expect(response.cookies.get('user_session')).toBeUndefined();
+    });
+
     it('should clear session cookie and redirect to Fief logout URL', async () => {
       const request = new NextRequest('http://localhost:3000/logout');
       const response = await middleware(request);

src/nextjs/index.ts

@@ -314,8 +314,13 @@ class FiefAuth {
       authenticate: this.fiefAuthEdge.authenticate(parameters),
     }));
     return async (request: NextRequest): Promise<NextResponse> => {
+      const isPrefetchRequest = request.headers.get('X-Middleware-Prefetch') === '1';
+
       // Handle login
       if (request.nextUrl.pathname === this.loginPath) {
+        if (isPrefetchRequest) {
+          return new NextResponse(null, { status: 204 });
+        }
         const authURL = await this.client.getAuthURL({ redirectURI: this.redirectURI, scope: ['openid'] });
         const response = NextResponse.redirect(authURL);
         const returnTo = request.nextUrl.searchParams.get('return_to');
@@ -327,6 +332,9 @@ class FiefAuth {
 
       // Handle authentication callback
       if (request.nextUrl.pathname === this.redirectPath) {
+        if (isPrefetchRequest) {
+          return new NextResponse(null, { status: 204 });
+        }
         const code = request.nextUrl.searchParams.get('code');
         const [tokens] = await this.client.authCallback(code as string, this.redirectURI);
 
@@ -349,6 +357,9 @@ class FiefAuth {
 
       // Handle logout
       if (request.nextUrl.pathname === this.logoutPath) {
+        if (isPrefetchRequest) {
+          return new NextResponse(null, { status: 204 });
+        }
         const logoutURL = await this.client.getLogoutURL({ redirectURI: this.logoutRedirectURI });
         const response = NextResponse.redirect(logoutURL);
         response.cookies.set(this.sessionCookieName, '', { maxAge: 0 });