ball_protobuf 0.3.0

Editions-capable, pure-Dart Protocol Buffers runtime: binary + proto3-JSON codecs, well-known types, gRPC framing, and the full protobuf Editions feature-resolution model. Portable across every Ball target.

ball_protobuf

An Editions-capable, pure-Dart Protocol Buffers runtime.

ball_protobuf is a descriptor-driven protobuf implementation written in Ball-portable Dart: binary wire codecs, binary and proto3-JSON marshal/unmarshal, well-known types, gRPC framing, and the complete protobuf Editions feature model + protoc's canonical feature-resolution algorithm (plus proto2/proto3 legacy inference).

Because it is authored in Ball-portable Dart, the same engine is compiled by the Ball toolchain to every target language — so editions-aware protobuf behaves identically on Dart, TypeScript, and C++ (see the portability matrix).

Editions features honoured

When a field descriptor carries a resolved 'features' map, the codecs honour:

• field_presence — EXPLICIT / IMPLICIT / LEGACY_REQUIRED
• enum_type — OPEN / CLOSED (out-of-range CLOSED values routed to unknowns)
• repeated_field_encoding — PACKED / EXPANDED
• message_encoding — LENGTH_PREFIXED / DELIMITED (groups, wire types 3/4)
• utf8_validation — VERIFY / NONE
• json_format — ALLOW / LEGACY_BEST_EFFORT

A descriptor without a 'features' key behaves as proto3 defaults (zero behavioural change), so existing callers are unaffected.

Conformance

The codecs are validated against the official protobuf conformance_test_runner for the Editions message TestAllTypesEdition2023 (all registered tests pass). See the conformance harness docs for how to build the runner and run it locally; CI runs it on every change.

Usage

import 'package:ball_protobuf/ball_protobuf.dart';

final bytes = marshal({'x': 7}, [
  {'name': 'x', 'number': 1, 'type': 'TYPE_INT32'},
]);
final decoded = unmarshal(bytes, [
  {'name': 'x', 'number': 1, 'type': 'TYPE_INT32'},
]);

// Resolve editions feature sets:
final features = baseFeaturesForEdition(edition2023);

Status

Part of the Ball language project; versioned in lockstep with the other Ball Dart packages. See the Editions spec for the feature tables and the Editions plan for design.