Test the file_save_data() function when a filename is provided.
function testWithFilename() {
$contents = $this
->randomName(8);
// Using filename with non-latin characters.
$filename = 'Текстовый файл.txt';
$result = file_save_data($contents, 'public://' . $filename);
$this
->assertTrue($result, t('Unnamed file saved correctly.'));
$this
->assertEqual('public', file_uri_scheme($result->uri), t("File was placed in Drupal's files directory."));
$this
->assertEqual($filename, drupal_basename($result->uri), t('File was named correctly.'));
$this
->assertEqual($contents, file_get_contents($result->uri), t('Contents of the file are correct.'));
$this
->assertEqual($result->filemime, 'text/plain', t('A MIME type was set.'));
$this
->assertEqual($result->status, FILE_STATUS_PERMANENT, t("The file's status was set to permanent."));
// Check that the correct hooks were called.
$this
->assertFileHooksCalled(array(
'insert',
));
// Verify that what was returned is what's in the database.
$this
->assertFileUnchanged($result, file_load($result->fid, TRUE));
}