[Feature/Fix] Redirect users back to previous URL upon sign in (#5)

* Redirect users back to previous URL upon sign in

* formatting

* helper

* formatting

---------

Co-authored-by: Taylor Otwell <taylor@laravel.com>

Author: joecampo

src/Http/Requests/AuthKitAuthenticationRequest.php

@@ -6,8 +6,11 @@
 use Illuminate\Auth\Events\Registered;
 use Illuminate\Foundation\Http\FormRequest;
 use Illuminate\Support\Facades\Auth;
+use Illuminate\Support\Facades\URL;
+use Inertia\Inertia;
 use Laravel\WorkOS\User;
 use Laravel\WorkOS\WorkOS;
+use Symfony\Component\HttpFoundation\Response;
 use WorkOS\UserManagement;
 
 class AuthKitAuthenticationRequest extends FormRequest
@@ -99,17 +102,41 @@ protected function updateUsing(AppUser $user, User $userFromWorkOS): AppUser
         ]);
     }
 
+    /**
+     * Redirect the user to the previous URL or a default URL if no previous URL is available.
+     */
+    public function redirect(string $default = '/'): Response
+    {
+        $previousUrl = rtrim(base64_decode($this->sessionState()['previous_url'] ?? '/')) ?: null;
+
+        $to = ! is_null($previousUrl) && $previousUrl !== URL::to('/')
+            ? $previousUrl
+            : $default;
+
+        return class_exists(Inertia::class)
+            ? Inertia::location($to)
+            : redirect($to);
+    }
+
     /**
      * Ensure the request state is valid.
      */
     protected function ensureStateIsValid(): void
     {
         $state = json_decode($this->query('state'), true)['state'] ?? false;
 
-        if ($state !== $this->session()->get('state')) {
+        if ($state !== ($this->sessionState()['state'] ?? false)) {
             abort(403);
         }
 
         $this->session()->forget('state');
     }
+
+    /**
+     * Get the session state.
+     */
+    protected function sessionState(): array
+    {
+        return json_decode($this->session()->get('state'), true) ?: [];
+    }
 }

src/Http/Requests/AuthKitLoginRequest.php

@@ -3,6 +3,7 @@
 namespace Laravel\WorkOS\Http\Requests;
 
 use Illuminate\Foundation\Http\FormRequest;
+use Illuminate\Support\Facades\URL;
 use Illuminate\Support\Str;
 use Inertia\Inertia;
 use Laravel\WorkOS\WorkOS;
@@ -20,11 +21,14 @@ public function redirect(): Response
 
         $url = (new UserManagement)->getAuthorizationUrl(
             config('services.workos.redirect_url'),
-            ['state' => $state = Str::random(20)],
+            $state = [
+                'state' => Str::random(20),
+                'previous_url' => base64_encode(URL::previous()),
+            ],
             'authkit',
         );
 
-        $this->session()->put('state', $state);
+        $this->session()->put('state', json_encode($state));
 
         return class_exists(Inertia::class)
             ? Inertia::location($url)