add all controllers logic

tests/Feature/Api/V1/System/DatabaseHealthControllerTest.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace Tests\Feature\Api\V1\System;
+
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class DatabaseHealthControllerTest extends TestCase
+{
+    use RefreshDatabase;
+
+    public function test_db_check_returns_ok(): void
+    {
+        $response = $this->getJson('/api/v1/system/db-check');
+
+        $response->assertOk();
+        $response->assertJsonPath('data.ok', true);
+    }
+}