Add tests for the Item.isBelong method.

tests/Feature/ItemTest.php

@@ -2,6 +2,7 @@
 
 namespace Tests\Feature;
 
+use App\Models\Company;
 use Illuminate\Foundation\Testing\RefreshDatabase;
 use Illuminate\Foundation\Testing\WithFaker;
 use Tests\TestCase;
@@ -10,6 +11,34 @@ use App\Models\Item;
 
 class ItemTest extends TestCase
 {
+    /* Item methods */
+
+    public function test_item_belong_right_company(): void
+    {
+        $right_company_name = 'testCompany';
+        $company = Company::where('name', $right_company_name)->first();
+
+        $item_name = 'Pizza Polo';
+        $item = Item::where('name', $item_name)->first();
+
+        $is_belong = $item->isBelong($company);
+
+        $this->assertTrue($is_belong);
+    }
+
+    public function test_item_belong_wrong_company(): void
+    {
+        $wrong_company_name = 'testCompany2';
+        $company = Company::where('name', $wrong_company_name)->first();
+
+        $item_name = 'Pizza Polo';
+        $item = Item::where('name', $item_name)->first();
+
+        $is_belong = $item->isBelong($company);
+
+        $this->assertFalse($is_belong);
+    }
+
     /* Item validation */
 
     public function test_item_with_empty_name(): void