<?php

/**

* DB connection constants

*

* Note: Don't hard code these values IRL. Use environmental variables

*/

const DB_HOST = 'database';

const DB_USER = 'root';

const DB_PASS = '';

/**

* Function to be tested

*

* Should connect to a database, retrieve the database version number.

*/

function getMysqlVersion(): string

{

$link = mysqli_connect(DB_HOST, DB_USER, DB_PASS);

if (mysqli_connect_errno()) {

throw new Exception("Connection failed: %s\n" . mysqli_connect_error());

}

$version = mysqli_get_server_version($link);

mysqli_close($link);

return $version;

}

/**

* PHPUnit test code

*

* This ensures that the database connection is made and the expected

* version integer is returned.

*/

use PHPUnit\Framework\TestCase;

class GetMysqlVersionTest extends TestCase

{

function testItConnectsAndReturnsCorrectVersion()

{

$result = getMysqlVersion();

$this->assertStringStartsWith('507', $result);

}

}