Add possibility to close underlying PDO connection

src/Database.php

@@ -19,6 +19,7 @@
 use Access\Driver\Sqlite;
 use Access\Entity;
 use Access\Exception;
+use Access\Exception\ClosedConnectionException;
 use Access\Lock;
 use Access\Presenter;
 use Access\Presenter\EntityPresenter;
@@ -44,9 +45,9 @@ class Database
     /**
      * PDO connection
      *
-     * @var \PDO $connection
+     * @var \PDO|null $connection
      */
-    private \PDO $connection;
+    private ?\PDO $connection;
 
     /**
      * Driver
@@ -128,9 +129,26 @@ public static function create(
      */
     public function getConnection(): \PDO
     {
+        if ($this->connection === null) {
+            throw new ClosedConnectionException();
+        }
+
         return $this->connection;
     }
 
+    /**
+     * Close the PDO connection by setting the property to null
+     *
+     * Note that in order for the connection to be closed, all it's instances
+     * must be set to null
+     *
+     * @return void
+     */
+    public function closeConnection(): void
+    {
+        $this->connection = null;
+    }
+
     /**
      * Set a new PDO connection
      *

src/Exception/ClosedConnectionException.php

@@ -0,0 +1,13 @@
+<?php
+
+namespace Access\Exception;
+
+use Access\Exception;
+
+class ClosedConnectionException extends Exception
+{
+    public function __construct()
+    {
+        parent::__construct('Connection is closed');
+    }
+}

tests/base/BaseDatabaseTest.php

@@ -15,6 +15,7 @@
 
 use Access\Database;
 use Access\Exception;
+use Access\Exception\ClosedConnectionException;
 use Access\Query;
 use PDO;
 use PHPUnit\Framework\TestCase;
@@ -325,4 +326,18 @@ public function testWithIncludeSoftDeleted(): void
         $user = $db->findOne(User::class, 1);
         $this->assertNotNull($user);
     }
+
+    public function testCloseConnection(): void
+    {
+        $db = static::createDatabaseWithDummyData();
+
+        $connection = $db->getConnection();
+        self::assertInstanceOf(PDO::class, $connection);
+
+        $db->closeConnection();
+
+        self::expectException(ClosedConnectionException::class);
+        self::expectExceptionMessage('Connection is closed');
+        $db->getConnection();
+    }
 }