[Merchant products API] Update product with mask

[jbaelo]

Environment details

• OS: Linux
• PHP version: 8.5
• Package name and version: google/shopping-merchant-products : 1.3.1

Steps to reproduce

Update product customLabel0 on supplemetary feed with FieldMask. The protobuf sends bad query params on update mask

Code example

        $attributes = new ProductAttributes()
            ->setCustomLabel0("Some value");
        $productInput = new ProductInput()
            ->setName("accounts/{{accountId}}/productInputs/{{productId}}")
            ->setProductAttributes($attributes);

        $updateMask = new FieldMask()
            ->setPaths(['product_attributes.custom_label_0']);

        $request = new UpdateProductInputRequest()
            ->setDataSource("accounts{{accountId}}/dataSources/{{dataSourceId}}")
            ->setProductInput($productInput)
            ->setUpdateMask($updateMask);

        $client->updateProductInput($request);

We get this error

{                                                                            
      "reason": "invalid",                                                     
      "domain": "merchantapi.googleapis.com",                                  
      "errorInfoMetadata": {                                                   
          "FIELD_LOCATION": "updateMask.paths[0]",                             
          "PATHS": "[product_attributes.custom_label0]",                       
          "REASON": "INVALID_FIELD_MASK_PATH"                                  
      },                                                                       
      "message": "[updateMask.paths[0]] Invalid field paths: [product_attribu  
  tes.custom_label0]",                                                         
      "code": 3,                                                               
      "status": "INVALID_ARGUMENT",                                            
      "details": [                                                             
          {                                                                    
              "@type": "type.googleapis.com\/google.rpc.ErrorInfo",            
              "reason": "invalid",                                             
              "domain": "merchantapi.googleapis.com",                          
              "metadata": {                                                    
                  "FIELD_LOCATION": "updateMask.paths[0]",                     
                  "PATHS": "[product_attributes.custom_label0]",               
                  "REASON": "INVALID_FIELD_MASK_PATH"                          
              }                                                                
          }                                                                    
      ]                                                                        
  }  

Lib should send product_attributes.custom_label_0 on query param updateMask

[bshaffer]

Yes you're right, it looks like the way that the field path is being derived is not converting the numbers to snake case properly (custom_label0 should be custom_label_0).

Can you tell me if you're using REST or gRPC? Judging by your error response, it appears that you're using REST. Please let me know if you get the same error with gRPC.

Another thing that would be a big help is if you could make the call using the APIs Explorer (click the API button in the right hand nav) and see if you get the same error message.

EDIT: looking at the code, we explictly convert the paths to camel case for FieldMask when converting to JSON, so the error here may indeed be on the server-side, specifically for REST requests.

[jbaelo]

We use REST because using gRPC with a validated decoded credentials file causes the gRPC transport to throw an error, creating an infinite loop.

However, this issue still occurs in the API Explorer when the mask is customLabel0; it does not happen when we use custom_label_0 or customLabel_0

[bshaffer]

If by gRPC infinite loop error, you're referring to grpc/grpc#39509, the error can be avoided by setting zend.max_allowed_stack_size = -1 in your php.ini

That may be the only feasible workaround, as I believe this is a server-side issue (the server should be able to accept customLabel0 as the field path)

[jbaelo]

Yes, running with grpc transport works.

Thanks @bshaffer i wil try to downgrade grpc.

[bshaffer]

@jbaelo hopefully that won't be necessary. You should be able to use the current version of grpc as long as you set zend.max_allowed_stack_size = -1.

As for this issue, I did some digging and turned on the protobuf.so extension. When I do this, I get the error "Underscore must be followed by a lowercase letter". This says to me that

1. I would expect this error to be happening in REST for all client library languages
2. The API seems to be out of compliance (since this error happens before the call is sent to the server)

This is concerning as there's no obvious fix (other than using gRPC instead of REST)

[bshaffer]

@jbaelo one more thing you can try is using a wildcard in the update mask:

        $updateMask = new FieldMask()
            ->setPaths(['product_attributes.*']);

I do not have any products set up so I cannot test this myself, but it appears to be supported

[jbaelo]

Using that mask probably will delete all non present attributes in the request

[bshaffer]

@jbaelo Please see protocolbuffers/protobuf#25786 (comment)

Unfortunately this is working as designed. I say unfortunately because 1. the FieldMask design is not ideal, and 2. the API knowingly named the fields in a non-compliant way, which is causing this issue. So gRPC is currently the only way I am aware of that you can bypass this error... either that, or by making direct JSON calls using the auth library.

[jbaelo]

Thanks @bshaffer for the support, we'll go for gRPC.