symfony/finder · error · InvalidArgumentException

Don't understand " " as a number test.

Error message

Don't understand "%s" as a number test.

What it means

NumberComparator's constructor validates the test against '#^\s*(==|!=|[<>]=?)?\s*([0-9\.]+)\s*([kmg]i?)?\s*$#i'; if the string is null or doesn't match (wrong characters, unsupported operators, text mixed in), it throws InvalidArgumentException with this message, echoing 'null' when null was passed.

Solutions

1. Format the test as [operator] number [k|m|g][i], e.g. '> 10M', '>= 1Gi', '== 500k'
2. Reject/normalize null before calling, and validate with the same regex
3. Remove commas, currency signs, and unsupported unit suffixes like 'b' or 'KB'

Example fix

// before
$finder->size('>= 10 MB'); // no match
// after
$finder->size('>= 10M'); // or '>= 10Mi' for binary megabytes

if (!is_string($size) || !preg_match('#^\s*(==|!=|[<>]=?)?\s*([0-9\.]+)\s*([kmg]i?)?\s*$#i', $size)) { throw new \InvalidArgumentException("Bad size test: $size"); }

function isValidSizeTest(mixed $v): bool { return is_string($v) && (bool) preg_match('#^\s*(==|!=|[<>]=?)?\s*([0-9\.]+)\s*([kmg]i?)?\s*$#i', $v); }

try { $finder->size($size); } catch (\InvalidArgumentException $e) { /* handle bad size test */ }

When it happens

Trigger: Finder::size(null), ->size('about 100'), ->size('==100MB') (unsupported 'b' suffix/multi-char units), ->size('>1,000') (comma), ->size('<>10'), or any string with characters outside digits, dot, optional k/m/g/i suffix.

Common situations: Users writing human sizes like '10 MB' instead of '10M' or '10Mi', passing null from unresolved config, using '===' or '=>' operators, thousands separators.

Understand the failure class

Background: "Invalid ... format", "must be in format X", "does not look like a ..." — invalid argument format errors across CLI tools and libraries — this error's family across 17 libraries.

Related errors

• Invalid number " ".
• Invalid operator " ".
• Don't understand " " as a date test.
• " " is not a valid date.
• Invalid PHP callback.

AI-assisted analysis of symfony/finder@4d6c057bfd (2026-09-13). Data as JSON: /api/errors/bd562ed6193d07d5. Report an issue: GitHub.

Appendix: source

Thrown at Comparator/NumberComparator.php:45

 *
 * @author    Fabien Potencier <fabien@symfony.com> PHP port
 * @author    Richard Clamp <richardc@unixbeard.net> Perl version
 * @copyright 2004-2005 Fabien Potencier <fabien@symfony.com>
 * @copyright 2002 Richard Clamp <richardc@unixbeard.net>
 *
 * @see http://physics.nist.gov/cuu/Units/binary.html
 */
class NumberComparator extends Comparator
{
    /**
     * @param string|null $test A comparison string or null
     *
     * @throws \InvalidArgumentException If the test is not understood
     */
    public function __construct(?string $test)
    {
        if (null === $test || !preg_match('#^\s*(==|!=|[<>]=?)?\s*([0-9\.]+)\s*([kmg]i?)?\s*$#i', $test, $matches)) {
            throw new \InvalidArgumentException(\sprintf('Don\'t understand "%s" as a number test.', $test ?? 'null'));
        }

        $target = $matches[2];
        if (!is_numeric($target)) {
            throw new \InvalidArgumentException(\sprintf('Invalid number "%s".', $target));
        }
        if (isset($matches[3])) {
            // magnitude
            switch (strtolower($matches[3])) {
                case 'k':
                    $target *= 1000;
                    break;
                case 'ki':
                    $target *= 1024;
                    break;
                case 'm':
                    $target *= 1000000;
                    break;

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