TestLog.php

<?php

namespace Drupal\error_service_test\Logger;

use Drupal\Core\Logger\RfcLoggerTrait;
use Psr\Log\LoggerInterface;

/**
 * Throws an exception while logging an exception.
 *
 * @see \Drupal\system\Tests\System\UncaughtExceptionTest::testLoggerException()
 */
class TestLog implements LoggerInterface {
    use RfcLoggerTrait;
    
    /**
     * {@inheritdoc}
     */
    public function log($level, $message, array $context = []) {
        $trigger = [
            '%type' => 'Exception',
            '@message' => 'Deforestation',
            '%function' => 'Drupal\\error_service_test\\MonkeysInTheControlRoom->handle()',
            'severity_level' => 3,
            'channel' => 'php',
        ];
        if (array_diff_assoc($trigger, $context) === []) {
            throw new \Exception('Oh, oh, frustrated monkeys!');
        }
    }

}