Kernel tests

Tests which extend Symfony\Bundle\FrameworkBundle\Test\KernelTestCase may be confusing to set up for first-time users. However, the required configuration is minimal.

Instructions

Minimal phpunit.xml configuration (extended by Symfony):

<?xml version="1.0" encoding="UTF-8"?>

<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="vendor/phpunit/phpunit/phpunit.xsd"
bootstrap="tests/bootstrap.php"
colors="true"

>

    <php>
        <ini name="display_errors" value="1" />
        <ini name="error_reporting" value="-1" />
        <ini name="memory_limit" value="2G" />

        <server name="APP_ENV" value="test" force="true" />
        <server name="SYMFONY_PHPUNIT_VERSION" value="9.5" />
    </php>

    <testsuites>
        <testsuite name="Unit">
            <directory>tests/Unit</directory>
        </testsuite>
        <testsuite name="Functional">
            <directory>tests/Functional</directory>
            <file>"tests/Functional/bootstrap.php"</file>
        </testsuite>
    </testsuites>

    <coverage processUncoveredFiles="true">
        <include>
            <directory suffix=".php">src</directory>
        </include>
    </coverage>

</phpunit>

KERNEL_CLASS=...\Kernel must be set in one of several places:

1. In phpunit.xml as <env name="KERNEL_CLASS" value="..."/>.
2. In.env.test and imported with an environment class, such as Symfony\Component\Dotenv\Dotenv.

In this case, inside tests there must be a bootstrap.php, and a secondary bootstrap.php inside tests/Functional for functional tests.

Minimal bootstrap.php:

<?php

declare(strict_types=1);

use Symfony\Component\Dotenv\Dotenv;

(new Dotenv())->bootEnv(dirname(__DIR__) . '/.env.test');

Functional tests which require an intricate setup can have its own bootstrap script which imports the real bootstrap and initiates the Kernel and the Application mechanisms.

Minimal functional bootstrap.php:

<?php

declare(strict_types=1);

require_once dirname(__DIR__) . '/bootstrap.php';

use Symfony\Bundle\FrameworkBundle\Console\Application;
use My\Kernel;

$kernel = new Kernel(environment: 'test', debug: false);

$kernel->boot();

$application = new Application($kernel);

// Set up...

In this case you can run bin/phpunit --testsuite Unit and bin/phpunit --testsuite Functional to trigger each bootstrap script separately.

Make sure to read the errors if there’s more issues.