MailFormatHelperTest.php

<?php

namespace Drupal\Tests\Core\Mail;

use Drupal\Core\Mail\MailFormatHelper;
use Drupal\Tests\UnitTestCase;

/**
 * @coversDefaultClass \Drupal\Core\Mail\MailFormatHelper
 * @group Mail
 */
class MailFormatHelperTest extends UnitTestCase {
    
    /**
     * @covers ::wrapMail
     */
    public function testWrapMail() {
        $delimiter = "End of header\n";
        $long_file_name = $this->randomMachineName(64) . '.docx';
        $headers_in_body = 'Content-Type: application/vnd.openxmlformats-officedocument.wordprocessingml.document; name="' . $long_file_name . "\"\n";
        $headers_in_body .= "Content-Transfer-Encoding: base64\n";
        $headers_in_body .= 'Content-Disposition: attachment; filename="' . $long_file_name . "\"\n";
        $headers_in_body .= 'Content-Description: ' . $this->randomMachineName(64);
        $body = $this->randomMachineName(76) . ' ' . $this->randomMachineName(6);
        $wrapped_text = MailFormatHelper::wrapMail($headers_in_body . $delimiter . $body);
        [
            $processed_headers,
            $processed_body,
        ] = explode($delimiter, $wrapped_text);
        // Check that the body headers were not wrapped even though some exceeded
        // 77 characters.
        $this->assertEquals($headers_in_body, $processed_headers, 'Headers in the body are not wrapped.');
        // Check that the body text is wrapped.
        $this->assertEquals(wordwrap($body, 77, " \n"), $processed_body, 'Body text is wrapped.');
    }

}