Firestore : Protobuf error when transactionID is null

[lemonlab]

When using the C implementation of protobuf, we can not use transactions in firestore, because protobuf is expecting a string for the transaction ID, and it may be null.

Exception :
User Error: Given value cannot be converted to string.

See : https://github.com/GoogleCloudPlatform/google-cloud-php/blob/master/src/Firestore/FirestoreClient.php#L438

    public function setRetryTransaction($var)
    {
        GPBUtil::checkString($var, False);
        $this->retry_transaction = $var;

        return $this;
    }

Steps to reproduce :

1 - Makes sure to use the C implementation of protobuf
pecl install protobuf
2 - Create a Firebase transaction

use Google\Cloud\Firestore\FirestoreClient;
use Google\Cloud\Firestore\Transaction;

$firestore = new FirestoreClient();
$document = $firestore->document('users/john');
$firestore->runTransaction(function (Transaction $transaction) use ($document) {
    // Manage Transaction.
});

An exception is raise even if the transaction contains no operation inside.

Stack trace

User Error: Given value cannot be converted to string.

  at vendor/google/proto-client/src/Google/Cloud/Firestore/V1beta1/TransactionOptions_ReadWrite.php:51
  at Google\Cloud\Firestore\V1beta1\TransactionOptions_ReadWrite->setRetryTransaction(null)
     (vendor/google/cloud-firestore/Connection/Grpc.php:111)
  at Google\Cloud\Firestore\Connection\Grpc->beginTransaction(array('database' => 'projects/project-XXXX/databases/(default)'))
     (vendor/google/cloud-firestore/FirestoreClient.php:454)
  at Google\Cloud\Firestore\FirestoreClient->Google\Cloud\Firestore\{closure}(object(Closure), array('maxRetries' => 5, 'begin' => array(), 'commit' => array(), 'rollback' => array()))
  at call_user_func_array(object(Closure), array(object(Closure), array('maxRetries' => 5, 'begin' => array(), 'commit' => array(), 'rollback' => array())))
     (vendor/google/cloud-core/Retry.php:78)
  at Google\Cloud\Core\Retry->execute(object(Closure), array(object(Closure), array('maxRetries' => 5, 'begin' => array(), 'commit' => array(), 'rollback' => array())))
     (vendor/google/cloud-firestore/FirestoreClient.php:485)
  at Google\Cloud\Firestore\FirestoreClient->runTransaction(object(Closure))

[jdpedrie]

Can you run php -v and pecl list and report the results?

[lemonlab]

php -v

PHP 7.1.13 (cli) (built: Jan  3 2018 17:31:04) ( NTS )
Copyright (c) 1997-2017 The PHP Group
Zend Engine v3.1.0, Copyright (c) 1998-2017 Zend Technologies
    with Zend OPcache v7.1.13, Copyright (c) 1999-2017, by Zend Technologies

pecl list

Installed packages, channel pecl.php.net:
=========================================
Package  Version State
grpc     1.9.0   stable
imagick  3.4.3   stable
protobuf 3.5.1.1 stable

[jdpedrie]

I'm having trouble triggering the error you've described. Can you try this and let me know if it fixes the issue? In src/Firestore/Connection/Grpc.php, replace beginTransaction() with the following:

    public function beginTransaction(array $args)
    {
        $rw = new TransactionOptions_ReadWrite;
        if ($retry = $this->pluck('retryTransaction', $args, false)) {
            $rw->setRetryTransaction($retry);
        }

        $args['options'] = new TransactionOptions;
        $args['options']->setReadWrite($rw);

        return $this->send([$this->firestore, 'beginTransaction'], [
            $this->pluck('database', $args),
            $this->addResourcePrefixHeader($args)
        ]);
    }

(Be sure you make this change in a clean copy of the library, WITHOUT the changes proposed in your pull request.)

[jdpedrie]

@lemonlab any luck with the code I shared?

[lemonlab]

Works perfectly, thank you !

[jdpedrie]

Great! I'll get a bugfix in. Thanks for the report.