added test for not author user

tests/Feature/Plan/EditTest.php

@@ -36,12 +36,23 @@ class EditTest extends TestCase
     {
         $plan = $this->plan;
         $plan->author()->attach($this->user->id);
+        $response = $this
+            ->actingAs($this->user)
+            ->get(route('plan.edit', $plan));
+        $response->assertSuccessful();
+    }
+
+    public function test_show_form_edit_plan_fail_for_not_author(): void
+    {
+        $plan = $this->plan;
+        $user = User::factory()->create();
+        $plan->author()->attach($user->id);
 
         $response = $this
             ->actingAs($this->user)
             ->get(route('plan.edit', $plan));
 
-        $response->assertSuccessful();
+        $response->assertForbidden();
     }
 
     public function test_publish_new_plan_success(): void