Request to add functionality for default value setting of 'proto-loader'

[0Ams]

Is your feature request related to a problem? Please describe.

syntax = "proto3";
package dummy;

service Test {
  rpc ping(PingParam) returns (PingReturn) {}
}
message PingParam {
  string __param = 1 [default = 'ping'];
}
message PingReturn {
  string __result = 1;
}

  const protoLoaderOptions: protoLoader.Options = {
    keepCase: true
    // longs: String,
    // enums: String,
    // defaults: true 
    // oneofs: true
  };
  const protoDescriptor = grpc.loadPackageDefinition(protoLoader.loadSync(path, protoLoaderOptions));

When used as above, protoLoader.Options only adds the default value when defaults: true.
I want the default value to enter only when there is a setting such as [default = 'XX'] within the proto file
If you set defaults: true, all fields will have default values.

Describe the solution you'd like

• It is recommended that the default value is set only if [default = ''] is set within the proto file.

Describe alternatives you've considered

• If the default value is set to [default = ''], shouldn't we choose to set only those fields

Additional context

• Nothing

PS. If have the same method as the function, please advise me. I thought there was no way to solve this. That's why we create an issue.

[murgatroid99]

In the proto3 syntax, all primitive fields always have a default value, determined by their type. The "default" field option just lets you change that default to a different value.

[0Ams]

@murgatroid99 If the default value is not defined in "proto3", but the default option is false in the loader, does it mean that the default value is entered?

I don't want all fields to have default values, and I want them to be set only for the fields I set. 😭

[murgatroid99]

The "defaults" option in the loader just determines whether it sets the default value for fields that don't have values when representing the message as an object. It doesn't change how default values are interpreted in the proto file.

There is an upcoming feature that may help you here: the "optional" field modifier was added to the proto3 syntax. When this library supports it, you will be able to set fields as "optional", which means that they will be omitted instead of having the default value set when they were omitted in the message.

[0Ams]

In the case of 'optional', it is restricted to use when creating stubs using grpc-tool.

I'm developing in multiple environments where I need to create a stub using grpc-tool and also use a grpc-loader, is there anything else I can solve both problems together?🥺

[murgatroid99]

In the case of 'option', it is restricted to use when creating stubs using grpc-tool.

I don't know what this means.

[0Ams]

In the case of 'optional', it is restricted to use when creating stubs using grpc-tool.

This meant that using stubs with grpc-tools caused an error and could not be used. Of course, this could be a problem with grpc-tools.

However, if you can use the default option flexibly in the proto-loader, it is convenient to use.

[murgatroid99]

The latest version of grpc-tools added support for optional fields. What version of grpc-tools do you have, and what error did you get?

[0Ams]

I can't remember it well because it's been a long time. But, it seems I was using 1.10.0 or 1.11.0.