Add DBConnection tests

qa-tests/src/Database/DbConnectionTest.php

+<?php
+
+use Q2A\Database\DbConnection;
+
+class DbConnectionTest extends PHPUnit_Framework_TestCase
+{
+	/** @var DbConnection */
+	private $dbConnection;
+
+	protected function setUp()
+	{
+		$this->dbConnection = new DbConnection();
+	}
+
+	public function test__applyArraySub_success()
+	{
+		$result = $this->dbConnection->applyArraySub('SELECT * FROM table WHERE field = 1', array());
+		$this->assertSame('SELECT * FROM table WHERE field = 1', $result);
+
+		$result = $this->dbConnection->applyArraySub('SELECT * FROM table WHERE field = ?', array(1));
+		$this->assertSame('SELECT * FROM table WHERE field = ?', $result);
+
+		$result = $this->dbConnection->applyArraySub('SELECT * FROM table WHERE field IN (?)', array(array(1)));
+		$this->assertSame('SELECT * FROM table WHERE field IN (?)', $result);
+
+		$result = $this->dbConnection->applyArraySub('SELECT * FROM table WHERE field IN (?)', array(array(1, 2)));
+		$this->assertSame('SELECT * FROM table WHERE field IN (?, ?)', $result);
+
+		$result = $this->dbConnection->applyArraySub('INSERT INTO table(field) VALUES ?', array(array(array(1))));
+		$this->assertSame('INSERT INTO table(field) VALUES (?)', $result);
+
+		$result = $this->dbConnection->applyArraySub('INSERT INTO table(field) VALUES ?', array(array(array(1), array(2))));
+		$this->assertSame('INSERT INTO table(field) VALUES (?), (?)', $result);
+
+		$result = $this->dbConnection->applyArraySub('INSERT INTO table(field1, field2) VALUES ?', array(array(array(1, 2))));
+		$this->assertSame('INSERT INTO table(field1, field2) VALUES (?, ?)', $result);
+
+		$result = $this->dbConnection->applyArraySub('INSERT INTO table(field1, field2) VALUES ?', array(array(array(1, 2), array(3, 4))));
+		$this->assertSame('INSERT INTO table(field1, field2) VALUES (?, ?), (?, ?)', $result);
+	}
+
+	public function test__applyArraySub_parameter_groups_with_different_element_count_error()
+	{
+		$this->setExpectedException('Q2A\Database\Exceptions\SelectSpecException');
+		$this->dbConnection->applyArraySub('INSERT INTO table(field1, field2) VALUES ?', array(array(array(1, 2), array(3))));
+	}
+}