diff --git a/tdd-project/tests/Unit/PdoDatabaseConnectionTest.php b/tdd-project/tests/Unit/PdoDatabaseConnectionTest.php
index 60b5283..fe9f43f 100644
--- a/tdd-project/tests/Unit/PdoDatabaseConnectionTest.php
+++ b/tdd-project/tests/Unit/PdoDatabaseConnectionTest.php
@@ -4,60 +4,121 @@
 
 use App\Contracts\DatabaseConnectionInterface;
 use App\Database\PDODatabaseConnection;
-use App\Exceptions\ConfigFileNotValidException;
-use App\Exceptions\PdoDatabaseException;
+use App\Exceptions\{ConfigFileNotFoundException, ConfigFileNotValidException, PdoDatabaseException};
 use App\Helpers\Config;
 use PDO;
 use PHPUnit\Framework\TestCase;
 
 class PdoDatabaseConnectionTest extends TestCase
 {
-    public function testPDOConnectionImplementsDatabaseConnectionInterface()
+    /**
+     *
+     *
+     * @return void
+     *
+     * @throws ConfigFileNotFoundException
+     * @throws ConfigFileNotValidException
+     */
+    public function testPDOConnectionImplementsDatabaseConnectionInterface(): void
     {
-        $connection = new PDODatabaseConnection($this->config());
-        $this->assertInstanceOf(DatabaseConnectionInterface::class, $connection);
+        $this->assertInstanceOf(DatabaseConnectionInterface::class, $this->connection());
     }
 
-    private function config()
+    /**
+     *
+     *
+     * @param array  $config
+     * @param string $operation
+     *
+     * @return PDODatabaseConnection
+     *
+     * @throws ConfigFileNotValidException|ConfigFileNotFoundException
+     */
+    private function connection(array $config = [], string $operation = ''): PDODatabaseConnection
     {
-        return Config::get('database', 'pdo_testing');
+        return new PDODatabaseConnection($this->config($config, $operation));
+    }
+
+    /**
+     *
+     *
+     * @param array  $data
+     * @param string $operation
+     *
+     * @return array|mixed|null
+     *
+     * @throws ConfigFileNotFoundException
+     */
+    private function config(array $data = [], string $operation = '')
+    {
+        $config = Config::get('database', 'pdo_testing');
+
+        switch ($operation) {
+            case 'merge':
+                return array_merge($config, $data);
+            case 'unset':
+                foreach ($data as $key) {
+                    unset($config[$key]);
+                }
+                return $config;
+        }
+
+        return $config;
     }
 
     /**
+     *
+     *
      * @depends testPdoDatabaseConnectionConnectMethodReturnValid
+     *
+     * @param $pdo
+     *
      * @return void
-     * @throws PdoDatabaseException
      */
-    public function testContentMethodShouldBeInstanceOfPdo($pdo)
+    public function testContentMethodShouldBeInstanceOfPdo($pdo): void
     {
         $this->assertInstanceOf(PDO::class, $pdo->getConnection());
     }
 
+    /**
+     *
+     *
+     * @return PDODatabaseConnection
+     *
+     * @throws ConfigFileNotValidException
+     * @throws PdoDatabaseException|ConfigFileNotFoundException
+     */
     public function testPdoDatabaseConnectionConnectMethodReturnValid(): PDODatabaseConnection
     {
-        $pdo = new PDODatabaseConnection($this->config());
-        $this->assertInstanceOf(PDODatabaseConnection::class, $pdo->connect());
-        return $pdo->connect();
+        $this->assertInstanceOf(PDODatabaseConnection::class, $this->connection()->connect());
+        return $this->connection()->connect();
     }
 
-    public function testPdoDatabaseReturnValidException()
+    /**
+     *
+     *
+     * @return void
+     *
+     * @throws ConfigFileNotValidException
+     * @throws PdoDatabaseException|ConfigFileNotFoundException
+     */
+    public function testPdoDatabaseReturnValidException(): void
     {
         $this->expectException(PdoDatabaseException::class);
-        $config = $this->config();
-        $config['database'] = md5(rand(9, 9999));
-        $pdo = new PDODatabaseConnection($config);
-        $pdo->connect();
+        $this->connection(['database' => 'Zrn3g22E3Tp'], 'merge')->connect();
     }
 
-    public function testConfigDatabaseConnectionIsValidKeys()
+    /**
+     *
+     *
+     * @return void
+     *
+     * @throws ConfigFileNotValidException
+     * @throws PdoDatabaseException|ConfigFileNotFoundException
+     */
+    public function testConfigDatabaseConnectionIsValidKeys(): void
     {
         $this->expectException(ConfigFileNotValidException::class);
-
-        $config = $this->config();
-        unset($config['db_username']);
-        unset($config['db_password']);
-
-        $pdo = new PDODatabaseConnection($config);
-        $pdo->connect();
+        $this->connection(['db_username', 'db_password'], 'unset')->connect();
     }
 }