This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE.

[Aleksandr Kalugin]

Gaufrette/src/Gaufrette/Adapter/Local.php

Line 64 in 0cf2aeb

 if (!@file_put_contents($path, $content)) { 

This function returns the number of bytes that were written to the file, or FALSE on failure.
This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE. Use the === operator for testing the return value of this function.

        $writedBytes = @file_put_contents($path, $content);
        if ($writedBytes === FALSE) {
            throw StorageFailure::unexpectedFailure('write', ['key' => $key]);
        }

        return $writedBytes;

[Nicolas MURE]

Thank you for pointing this out @gregsparrow 👍
Fixed in #561 .