[6.x] Allow control over who can be impersonated in UserPolicy

src/Actions/Impersonate.php

@@ -24,7 +24,11 @@ public function visibleTo($item)
             return false;
         }
 
-        return $item instanceof UserContract && $item->id() != User::current()->id();
+        if (! ($item instanceof UserContract && $item->id() != User::current()->id())) {
+            return false;
+        }
+
+        return User::current()->can('impersonate', $item);
     }
 
     public function visibleToBulk($items)
@@ -34,7 +38,7 @@ public function visibleToBulk($items)
 
     public function authorize($authed, $user)
     {
-        return $authed->can('impersonate users');
+        return $authed->can('impersonate', $user);
     }
 
     public function run($users, $values)

src/Policies/UserPolicy.php

@@ -67,4 +67,11 @@ public function sendPasswordReset($authed, $user)
     {
         return $this->edit($authed, $user);
     }
+
+    public function impersonate($authed, $user)
+    {
+        $authed = User::fromUser($authed);
+
+        return $authed->hasPermission('impersonate users');
+    }
 }

tests/Actions/ImpersonateTest.php

@@ -2,17 +2,22 @@
 
 namespace Tests\Actions;
 
+use Illuminate\Support\Facades\Gate;
 use PHPUnit\Framework\Attributes\Group;
 use PHPUnit\Framework\Attributes\Test;
+use Statamic\Actions\Impersonate as Action;
 use Statamic\Facades\User;
+use Statamic\Policies\UserPolicy;
 use Tests\ElevatesSessions;
+use Tests\FakesRoles;
 use Tests\PreventSavingStacheItemsToDisk;
 use Tests\TestCase;
 
 #[Group('elevated-session')]
 class ImpersonateTest extends TestCase
 {
     use ElevatesSessions;
+    use FakesRoles;
     use PreventSavingStacheItemsToDisk;
 
     private function impersonate($user)
@@ -41,4 +46,87 @@ public function it_authenticates_as_another_user_and_clears_elevated_session()
         $this->assertEquals($impersonated->id(), auth()->id());
         $this->assertFalse(request()->hasElevatedSession());
     }
+
+    #[Test]
+    public function it_is_visible_to_a_valid_target_user()
+    {
+        $impersonator = tap(User::make()->email('admin@example.com')->makeSuper())->save();
+        $impersonated = tap(User::make()->email('user@example.com'))->save();
+
+        $this->actingAs($impersonator);
+
+        $this->assertTrue((new Action)->visibleTo($impersonated));
+    }
+
+    #[Test]
+    public function it_is_not_visible_when_policy_denies_impersonation()
+    {
+        $this->setTestRoles(['impersonator' => ['impersonate users']]);
+
+        $impersonator = tap(User::make()->email('admin@example.com')->assignRole('impersonator'))->save();
+        $impersonated = tap(User::make()->email('user@example.com'))->save();
+
+        Gate::policy(get_class($impersonated), DenyImpersonationPolicy::class);
+
+        $this->actingAs($impersonator);
+
+        $this->assertFalse((new Action)->visibleTo($impersonated));
+    }
+
+    #[Test]
+    public function it_is_authorized_with_the_default_policy()
+    {
+        $this->setTestRoles(['impersonator' => ['impersonate users']]);
+
+        $impersonator = tap(User::make()->email('admin@example.com')->assignRole('impersonator'))->save();
+        $impersonated = tap(User::make()->email('user@example.com'))->save();
+
+        $this->assertTrue((new Action)->authorize($impersonator, $impersonated));
+    }
+
+    #[Test]
+    public function it_is_not_authorized_when_policy_denies_impersonation()
+    {
+        $this->setTestRoles(['impersonator' => ['impersonate users']]);
+
+        $impersonator = tap(User::make()->email('admin@example.com')->assignRole('impersonator'))->save();
+        $impersonated = tap(User::make()->email('user@example.com'))->save();
+
+        Gate::policy(get_class($impersonated), DenyImpersonationPolicy::class);
+
+        $this->assertFalse((new Action)->authorize($impersonator, $impersonated));
+    }
+
+    #[Test]
+    public function it_is_not_authorized_without_permission()
+    {
+        $this->setTestRoles(['editor' => ['edit users']]);
+
+        $impersonator = tap(User::make()->email('admin@example.com')->assignRole('editor'))->save();
+        $impersonated = tap(User::make()->email('user@example.com'))->save();
+
+        $this->assertFalse((new Action)->authorize($impersonator, $impersonated));
+    }
+
+    #[Test]
+    public function super_users_bypass_the_policy_check()
+    {
+        $impersonator = tap(User::make()->email('admin@example.com')->makeSuper())->save();
+        $impersonated = tap(User::make()->email('user@example.com'))->save();
+
+        Gate::policy(get_class($impersonated), DenyImpersonationPolicy::class);
+
+        $this->actingAs($impersonator);
+
+        $this->assertTrue((new Action)->visibleTo($impersonated));
+        $this->assertTrue((new Action)->authorize($impersonator, $impersonated));
+    }
+}
+
+class DenyImpersonationPolicy extends UserPolicy
+{
+    public function impersonate($authed, $user)
+    {
+        return false;
+    }
 }