Tests the formatters.
public function testFormatter() {
$entity = entity_create('entity_test', array());
$entity->{$this->fieldName}->value = 1;
$build = field_view_field($entity, $this->fieldName, array());
$this
->assertEqual($build['#formatter'], 'list_default', 'Ensure to fall back to the default formatter.');
$this
->assertEqual($build[0]['#markup'], 'One');
$build = field_view_field($entity, $this->fieldName, array(
'type' => 'list_key',
));
$this
->assertEqual($build['#formatter'], 'list_key', 'The chosen formatter is used.');
$this
->assertEqual($build[0]['#markup'], 1);
}