Enable interface translation to English
function testEnglishTranslation() {
$admin_user = $this
->drupalCreateUser(array(
'administer languages',
'access administration pages',
));
$this
->drupalLogin($admin_user);
$this
->drupalPost('admin/config/regional/language/edit/en', array(
'locale_translate_english' => TRUE,
), t('Save language'));
$this
->assertLinkByHref('/admin/config/regional/translate/translate?langcode=en', 0, t('Enabled interface translation to English.'));
}