rpc_dart_generator

Code generator for caller/responder wrappers in rpc_dart.

• Generates Names (service + method constants, Names.instance(suffix) for multiple instances).
• Generates a final caller and an abstract responder (you implement handlers; setup() registers them).
• Codecs: by default inserts RpcCodec<T>.withDecoder(T.fromJson); if transferMode is zeroCopy no codecs/serialization checks are added.
• Cooperative with other source_gen builders: uses SharedPartBuilder/combining_builder to merge into the same *.g.dart instead of writing it directly.

Annotations

• @RpcService(name, transferMode?) — declares service name and default transfer mode (auto/codec/zeroCopy).
• @RpcMethod(name, kind, requestCodec?, responseCodec?, transferMode?) — method id, RPC kind, optional codecs and per-method transfer mode.

Per-method transferMode overrides the service. In zeroCopy codecs are omitted and IRpcSerializable check is skipped. In auto/codec, if codecs are not provided, RpcCodec<T>.withDecoder(T.fromJson) is added (requires static fromJson).

Example (zero-copy, multiple instances)

See example/lib/calculator_contract.dart and example/bin/main.dart:

responderEndpoint.registerServiceContract(
  CalculatorContractResponder(
    serviceNameOverride: CalculatorContractNames.instance('alpha'),
  ),
);
responderEndpoint.registerServiceContract(
  CalculatorContractResponder(
    serviceNameOverride: CalculatorContractNames.instance('beta'),
  ),
);

final caller = CalculatorContractCaller(
  RpcCallerEndpoint(transport: callerTransport),
  serviceNameOverride: CalculatorContractNames.instance('beta'),
);
final res = await caller.sum(SumRequest(values: [1, 2, 3]));

Example (auto codec)

example/lib/calculator_with_codec.dart:

@RpcService(name: 'CalculatorCodec')
abstract class ICalculatorCodecContract {
  @RpcMethod(name: 'sum')
  Future<SumResponse> sum(SumRequest request, {RpcContext? context});
}

example/bin/main_codec.dart registers under Names.instance('json') and calls it.

Generate

fvm dart pub get
fvm dart run build_runner build

The builder emits .rpc_dart.g.part fragments to the build cache; source_gen|combining_builder produces the final *.g.dart, allowing rpc_dart output to live alongside other generators (e.g. json_serializable) without collisions.

Transfer modes

• auto/codec: if codecs are absent → default RpcCodec<T>.withDecoder(T.fromJson); if provided → use them.
• zeroCopy: no codecs generated, no IRpcSerializable check (any Object), intended for zero-copy transports.

Codec/transfer matrix

Validation

• Signatures must match kind: unary → Future<T> func(T req, {RpcContext? context}); streams → corresponding Stream/Future.
• RpcContext is the only allowed named parameter.
• In auto/codec, types must be serializable (IRpcSerializable or primitive), otherwise generation fails.