[FIXED] What is the default order of file elements in Symfony finder?

Issue

The following code returns different results in two environments (which however were supposed to be as close to one another as possible: the same PHP version, etc.)

The /var/www/html/project/vendor/package/path/to/some/folder directory contains exactly the same set of files in both environments. The files themselves were put there by composer.

use Symfony\Component\Finder\Finder;

// Don't mind this. The real app uses an autoloading mechanism.
require __DIR__ . '/../vendor/symfony/finder/Finder.php';
require __DIR__ . '/../vendor/symfony/finder/SplFileInfo.php';
require __DIR__ . '/../vendor/symfony/finder/Iterator/FilterIterator.php';
require __DIR__ . '/../vendor/symfony/finder/Iterator/RecursiveDirectoryIterator.php';
require __DIR__ . '/../vendor/symfony/finder/Iterator/ExcludeDirectoryFilterIterator.php';
require __DIR__ . '/../vendor/symfony/finder/Iterator/MultiplePcreFilterIterator.php';
require __DIR__ . '/../vendor/symfony/finder/Iterator/PathFilterIterator.php';
require __DIR__ . '/../vendor/symfony/finder/Iterator/FilenameFilterIterator.php';
require __DIR__ . '/../vendor/symfony/finder/Iterator/FileTypeFilterIterator.php';

$path = '/var/www/html/project/vendor/package/path/to/some/folder';
$path = Finder::create()->files()->followLinks()->name('/\.(php|inc|hh)$/')->in($path);

$iterator = $path->getIterator();
$iterator->rewind();
$current = $iterator->current();
echo $current->getRelativePathname();

It isn't random. The results are consistent in a single environment. But a different path name is diplayed in either environment. I was able to trace it down to PHP's native: FilterIterator::rewind, but I'm not sure if rewinding is the problem here.

Solution

There is no defined "default" order for the Finder component.

Finder's iterator (Symfony\Component\Finder\Iterator\RecursiveDirectoryIterator) extends on the core \RecursiveDirectoryIterator, which does not define a default order (nor a way to "set" the order). The ordering is thus not guaranteed defined or guaranteed. It is highly system-dependant and file-system dependant, and should not be be relied upon.

If you need a dependable, consistent sort order, just use the appropriate sort*() methods on the Finder instance. This will cause the result to be wrapped on a SortableIterator when you call getIterator(), and get you results ordered in a predictable manner.

Answered By - yivi