AsyncAws S3: Replace special characters by XML entity codes

[stevenrombauts]

When calling deleteDirectory(), we want to make sure that special characters (', ", &, < and >) are replaced by their XML entity code. If not, the following code will result in the error below:

$client = new AsyncAws\S3\S3Client([
    'accessKeyId' => '...',
    'accessKeySecret' => '...',
    'region' => 'eu-west-1',
]);

$adapter = new League\Flysystem\AsyncAwsS3\AsyncAwsS3Adapter($client, 'urlencode-test');
$filesystem = new League\Flysystem\Filesystem($adapter);

$filesystem->write('dir-to-delete/\'"&<>.json', '{"foo": "bar"}');
$filesystem->deleteDirectory('dir-to-delete');

This will result in:

Warning: DOMDocument::createElement(): unterminated entity reference         <>.json in flysystem/vendor/async-aws/s3/src/ValueObject/ObjectIdentifier.php on line 124

Fatal error: Uncaught AsyncAws\Core\Exception\Http\ClientException: HTTP 400 returned for "https://urlencode-test.s3.eu-west-3.amazonaws.com/?delete=".

Code:    UserKeyMustBeSpecified
Message: User key must be specified.

Also see AWS docs here: https://docs.aws.amazon.com/AmazonS3/latest/userguide/object-keys.html#object-key-xml-related-constraints

[frankdejonge]

@stevenrombauts can you add a test case that verifies the error so we prevent regressions? The rest looks good 👍

[stevenrombauts]

@frankdejonge Do you mean to verify the exception that can be thrown by this new code, or do you mean something else?

[frankdejonge]

@stevenrombauts yes, verify that the guard works. Essentially a test that fails when the check is removed.

[stevenrombauts]

@frankdejonge Thanks, got it. I've added that test now, let me know if that works!