<?php

/**

* DB connection constants

*/

const DB_HOST = 'database';

const DB_USER = 'root';

const DB_PASS = '';

const DB_DATABASE = 'test';

const DB_TABLE = 'test_table';

function getLink(): mysqli

{

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

if (mysqli_connect_errno()) {

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

}

return $link;

}

/**

* Function to be tested

*

* Creates a table with JSON fields, a feature only available in MySQL 5.7+.

*/

function createTableWithJsonFields(): bool

{

$link = getLink();

mysqli_select_db($link, DB_DATABASE);

$createTableQuery = 'CREATE TABLE IF NOT EXISTS '.DB_TABLE.' (id INT, json_field JSON);';

if (!$result = mysqli_query($link, $createTableQuery)) {

throw new Exception("Table could not be created.");

}

mysqli_close($link);

return $result;

}

/**

* Gets the schema for our newly created table.

*/

function getSchema(): array

{

$link = getLink();

$createTableQuery = 'DESCRIBE '.DB_DATABASE.'.'.DB_TABLE.';';

if (!$result = mysqli_query($link, $createTableQuery)) {

throw new Exception("Table could not be created.");

}

mysqli_close($link);

return $result->fetch_all();

}

/**

* PHPUnit test code

*

* This ensures that the database connection is made and the table is created.

*/

use PHPUnit\Framework\TestCase;

class CreateJsonFieldTest extends TestCase

{

function testItConnectsAndCreatesTableWithJsonField()

{

$result = createTableWithJsonFields();

$newTable = getSchema();

$this->assertTrue($result);

$this->assertEquals('int(11)', $newTable[0][1]);

$this->assertEquals('json', $newTable[1][1]);

}

}