Support nested messages in GET request queries

Description

service MyService {
    rpc myMethod (myMethodRequest) returns (myMethodResponse) {
        option (google.api.http) = {
            get: "/method/all"
        };
    }
}

message myMethodRequest {
    repeated Scoped scope = 1;

    message Scoped {
        oneof condition {
            ById by_id = 1;
        }
        message ById {
            uint32 id = 1;
        }
    }
}

message myMethodResponse {
    repeated uint32 ids = 1;
}

localhost:8080/method/all?scope.by_id.id=3

unexpected repeated field in scope.by_id.id

Contributor guide

Tech stack

gogrpcrest api

Domain

apibackend

Issue type

feature

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

3

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

1-2 days

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

stale

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

clear

Prerequisites

GogRPCProtocol BuffersHTTP query parameter parsing

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

35

Research direction

Investigate the query parameter parsing logic in the grpc gateway's runtime package (likely `runtime/query.go`). The issue is that nested repeated messages within a `oneof` are not handled correctly when flattening query parameters. Examine how the gateway currently parses fields like `scope.by id.id` and why it triggers an 'unexpected repeated field' error. Look at the protobuf definition: `myMethodRequest.Scoped` contains a `oneof condition` with `ById`. The gateway should support `scope.by id.id` as a valid query parameter. Check existing tests for query parameter parsing to understand expected behavior. Consider how the gateway handles repeated fields (repeated Scoped scope) and nested messages. The solution likely involves modifying the parser to correctly traverse `oneof` fields and allow nested access. Review any comments or linked discussions in the issue for additional context.