Error when sending a GTIN value to the Merchant API

[steve-ico3]

Environment details

• PHP version: 8.2
• Package name and version: php-shopping-merchant-products v0.1.0 (possibly protobuf)

Steps to reproduce

1. Send a product up to merchant using InsertProductInputRequest and insertProductInput
2. Include a gtin value on the attribute e.g. 5054511953633
3. The product lists correctly in merchant, but the response throws an exception

Error comes back as Error occurred during parsing: Error occurred during parsing: String field only accepts string value

Google\Protobuf\Internal\Message line 874 gets triggered and when I output the value it's

array(1) {
  [0]=>string(13) "5054511953633"
}

When it should be a string, but that's in the API response not the data sent so it's not something I set / can fix

Code example

Won't provide the specific product details but it's when you send gtin

        $request = new InsertProductInputRequest();

        $request
            ->setParent(ProductInputsServiceClient::accountName($this->accountId))
            ->setDataSource(DataSourcesServiceClient::dataSourceName($this->accountId, $dataSourceId))
            ->setProductInput($productInput);

        $response = $this->getProductInputClient()->insertProductInput($request);

If the product sent doesn't have a GTIN value then it all works correctly

It also occurs when you just call listProducts if you have submitted a product with a GTIN value already

So I think there's a mapping issue somewhere making it think GTIN is an array when it should be a string

I could provide my merchant account and a specific example product if needed but obviously not on a public issue