Protobuf.js: snake_case properties are silently dropped.

[RP-3]

protobuf.js version: 6.8.0

Encoding a valid, plain object with snake_case properties causes those properties to be dropped when encoding. If camelCase is used, everything works as expected.

Minimal snippet of JS below:

protobuf.load(`${__dirname}/test2.proto`)
.then(function(root) {

    const LocationUpdateEvent = root.lookupType('LocationServiceLocationUpdateV1');

    const examplePayload = {
        user_id: 'a user ID',
        requestId: 'a request ID'
    };

    var errMsg = LocationUpdateEvent.verify(examplePayload);
    if (errMsg){
        console.error(errMsg);
        throw Error(errMsg);
    }

    const lue = LocationUpdateEvent.create(examplePayload);
    console.log('lue', lue, '\n');
    // logs `lue LocationServiceLocationUpdateV1 { user_id: 'a user ID', requestId: 'a request ID' }`

    const buf = LocationUpdateEvent.encode(lue).finish();
    console.log('buf', buf, '\n');
    // logs `buf <Buffer 12 0c 61 20 72 65 71 75 65 73 74 20 49 44>`

    const returnedLue = LocationUpdateEvent.decode(buf);
    console.log('returnedLue', returnedLue, '\n');
    // logs `returnedLue LocationServiceLocationUpdateV1 { requestId: 'a request ID' }`
    // notice, `user_id` is missing!
    console.log('keys', Object.keys(returnedLue), '\n');
    // logs `keys [ 'requestId' ]`, just a sanity check

    const backInJson = LocationUpdateEvent.toObject(returnedLue);
    console.log('backInJson', backInJson, '\n');
    // logs `backInJson { requestId: 'a request ID' }`. One property got lost.
});

Definition from test2.proto:

syntax = "proto3";

message LocationServiceLocationUpdateV1 {

    string user_id = 1;
    string requestId = 2;
}

[elomar]

I just ran into this. noticed afterwards that the examples mention that awesome_field becomes awesomeField. any reason in particular for this mapping? would it make sense to error instead of dropping data silently?

[dcodeIO]

The default is camel case because that's the more JavaScripty-notation and because Google's official library is doing the same.

There is also an option to retain snake case when using Root#load:

var root = new Root();
root.load("someFile,proto", { keepCase: true }).then(() => {
  ...
});

There's an equal option for pbjs as well.

Not a fan of adding (most of the time redundant) assertions for the respective incorrect opposite there.

[elomar]

thanks for the clarification

[RP-3]

This makes sense. I missed the line in the docs that shows awesome_field // becomes awesome_field. Thanks very much :)