Create a package that implements a JSON-RPC 2.0 server.

pkg/json_rpc_2/test/server/utils.dart

+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+library json_rpc_2.test.server.util;
+
+import 'package:unittest/unittest.dart';
+import 'package:json_rpc_2/json_rpc_2.dart' as json_rpc;
+
+void expectErrorResponse(json_rpc.Server server, request, int errorCode,
+    String message) {
+  var id;
+  if (request is Map) id = request['id'];
+
+  expect(server.handleRequest(request), completion(equals({
+    'jsonrpc': '2.0',
+    'id': id,
+    'error': {
+      'code': errorCode,
+      'message': message,
+      'data': {'request': request}
+    }
+  })));
+}
+
+Matcher throwsInvalidParams(String message) {
+  return throwsA(predicate((error) {
+    expect(error, new isInstanceOf<json_rpc.RpcException>());
+    expect(error.message, equals(message));
+    return true;
+  }));
+}