test/service_test.dart

library service_test;

import 'dart:async' show Future;

import 'package:protobuf/protobuf.dart';
import 'package:unittest/unittest.dart';

import '../out/protos/service.pb.dart' as pb;

class SearchService extends pb.SearchServiceBase {
    Future<pb.SearchResponse> search(
        ServerContext ctx, pb.SearchRequest request) async {
      var out = new pb.SearchResponse();
      if (request.query == 'hello' || request.query == 'world') {
        out.result.add('hello, world!');
      }
      return out;
    }
}

class FakeJsonServer {
  final GeneratedService searchService;
  FakeJsonServer(this.searchService);

  Future<String> messageHandler(
      String serviceName, String methodName, String requestJson) async {
    if (serviceName == 'SearchService') {
      GeneratedMessage request = searchService.createRequest(methodName);
      request.mergeFromJson(requestJson);
      var ctx = new ServerContext();
      var reply = await searchService.handleCall(ctx, methodName, request);
      return reply.writeToJson();
    } else {
      throw 'unknown service: $serviceName';
    }
  }
}

class FakeJsonClient implements RpcClient {
  final FakeJsonServer server;
  FakeJsonClient(this.server);

  Future<GeneratedMessage> invoke(
    ClientContext ctx, String serviceName, String methodName,
    GeneratedMessage request, GeneratedMessage response) async {

    String requestJson = request.writeToJson();
    String replyJson =
        await server.messageHandler(serviceName, methodName, requestJson);
    response.mergeFromJson(replyJson);
    return response;
  }
}

void main() {
  var server = new FakeJsonServer(new SearchService());
  var api = new pb.SearchServiceApi(new FakeJsonClient(server));

  test('end to end RPC using JSON', () async {
    var request = new pb.SearchRequest()
      ..query = "hello";
    var reply = await api.search(new ClientContext(), request);
    expect(reply.result, ["hello, world!"]);
  });
}