CountryCodeConstraintTest.php

<?php

declare (strict_types=1);
namespace Drupal\Tests\Core\Validation\Plugin\Validation\Constraint;

use Drupal\Core\DependencyInjection\ContainerBuilder;
use Drupal\Core\Locale\CountryManagerInterface;
use Drupal\Core\Validation\Plugin\Validation\Constraint\CountryCodeConstraint;
use Drupal\Tests\UnitTestCase;
use Symfony\Component\Validator\Constraints\Choice;

/**
 * @covers \Drupal\Core\Validation\Plugin\Validation\Constraint\CountryCodeConstraint
 * @group validation
 */
class CountryCodeConstraintTest extends UnitTestCase {
    public function testConstraintLoadsChoicesFromCountryManager() : void {
        $countries = [
            'US' => 'United States',
            'CA' => 'Canada',
            'MX' => 'Mexico',
        ];
        // The CountryCode constraint should call the country manager's getList()
        // method to compile a list of valid choices.
        $country_manager = $this->createMock(CountryManagerInterface::class);
        $country_manager->expects($this->atLeastOnce())
            ->method('getList')
            ->willReturn($countries);
        $container = new ContainerBuilder();
        $container->set(CountryManagerInterface::class, $country_manager);
        $constraint = CountryCodeConstraint::create($container, [], 'CountryCode', []);
        $this->assertInstanceOf(Choice::class, $constraint);
        $this->assertSame(array_keys($countries), $constraint->choices);
    }

}