Tests file_usage()->add().
function testAddUsage() {
$file = $this
->createFile();
file_usage()
->add($file, 'testing', 'foo', 1);
// Add the file twice to ensure that the count is incremented rather than
// creating additional records.
file_usage()
->add($file, 'testing', 'bar', 2);
file_usage()
->add($file, 'testing', 'bar', 2);
$usage = db_select('file_usage', 'f')
->fields('f')
->condition('f.fid', $file->fid)
->execute()
->fetchAllAssoc('id');
$this
->assertEqual(count($usage), 2, t('Created two records'));
$this
->assertEqual($usage[1]->module, 'testing', t('Correct module'));
$this
->assertEqual($usage[2]->module, 'testing', t('Correct module'));
$this
->assertEqual($usage[1]->type, 'foo', t('Correct type'));
$this
->assertEqual($usage[2]->type, 'bar', t('Correct type'));
$this
->assertEqual($usage[1]->count, 1, t('Correct count'));
$this
->assertEqual($usage[2]->count, 2, t('Correct count'));
}