feat: handle redirectTo query parameter in middleware

apps/remix/app/routes/_unauthenticated+/signin.tsx

@@ -1,6 +1,7 @@
 import { Trans } from '@lingui/react/macro';
 import { Link, redirect } from 'react-router';
 
+import { extractCookieFromHeaders } from '@documenso/auth/server/lib/utils/cookies';
 import { getOptionalSession } from '@documenso/auth/server/lib/utils/get-session';
 import {
   IS_GOOGLE_SSO_ENABLED,
@@ -20,13 +21,18 @@ export function meta() {
 
 export async function loader({ request }: Route.LoaderArgs) {
   const { isAuthenticated } = await getOptionalSession(request);
+  const redirectToCookie = extractCookieFromHeaders('redirectTo', request.headers);
+  const redirectToAfterLogin = redirectToCookie ? decodeURIComponent(redirectToCookie) : '';
 
-  // SSR env variables.
   const isGoogleSSOEnabled = IS_GOOGLE_SSO_ENABLED;
   const isOIDCSSOEnabled = IS_OIDC_SSO_ENABLED;
   const oidcProviderLabel = OIDC_PROVIDER_LABEL;
 
   if (isAuthenticated) {
+    if (redirectToAfterLogin) {
+      throw redirect(redirectToAfterLogin);
+    }
+
     throw redirect('/documents');
   }
 
@@ -34,11 +40,13 @@ export async function loader({ request }: Route.LoaderArgs) {
     isGoogleSSOEnabled,
     isOIDCSSOEnabled,
     oidcProviderLabel,
+    redirectToAfterLogin,
   };
 }
 
 export default function SignIn({ loaderData }: Route.ComponentProps) {
-  const { isGoogleSSOEnabled, isOIDCSSOEnabled, oidcProviderLabel } = loaderData;
+  const { isGoogleSSOEnabled, isOIDCSSOEnabled, oidcProviderLabel, redirectToAfterLogin } =
+    loaderData;
 
   return (
     <div className="w-screen max-w-lg px-4">
@@ -56,6 +64,7 @@ export default function SignIn({ loaderData }: Route.ComponentProps) {
           isGoogleSSOEnabled={isGoogleSSOEnabled}
           isOIDCSSOEnabled={isOIDCSSOEnabled}
           oidcProviderLabel={oidcProviderLabel}
+          returnTo={redirectToAfterLogin ?? undefined}
         />
 
         {env('NEXT_PUBLIC_DISABLE_SIGNUP') !== 'true' && (

apps/remix/server/middleware.ts

@@ -18,13 +18,32 @@ export const appMiddleware = async (c: Context, next: Next) => {
   const { req } = c;
   const { path } = req;
 
+  // PRE-HANDLER CODE: Place code here to execute BEFORE the route handler runs.
+  const redirectTo = req.query('redirectTo');
+
+  if (redirectTo) {
+    if (redirectTo.startsWith('/') && !redirectTo.startsWith('//') && !redirectTo.includes('..')) {
+      debug.log('Setting redirectTo cookie to:', redirectTo);
+      setCookie(c, 'redirectTo', redirectTo, {
+        path: '/',
+        httpOnly: true,
+        sameSite: 'Lax',
+        maxAge: 150,
+        // secure: process.env.NODE_ENV === 'production'
+      });
+
+      debug.log('Redirecting to (from param):', redirectTo);
+      return c.redirect(redirectTo, 307);
+    } else {
+      debug.log('Invalid redirectTo parameter encountered:', redirectTo);
+    }
+  }
+
   // Paths to ignore.
   if (nonPagePathRegex.test(path)) {
     return next();
   }
 
-  // PRE-HANDLER CODE: Place code here to execute BEFORE the route handler runs.
-
   await next();
 
   // POST-HANDLER CODE: Place code here to execute AFTER the route handler completes.