test/server/server_test.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.

import 'dart:convert';

import 'package:test/test.dart';
import 'package:json_rpc_2/error_code.dart' as error_code;
import 'package:json_rpc_2/json_rpc_2.dart' as json_rpc;

import 'utils.dart';

void main() {
  var controller;
  setUp(() => controller = new ServerController());

  test("calls a registered method with the given name", () {
    controller.server.registerMethod('foo', (params) {
      return {'params': params.value};
    });

    expect(
        controller.handleRequest({
          'jsonrpc': '2.0',
          'method': 'foo',
          'params': {'param': 'value'},
          'id': 1234
        }),
        completion(equals({
          'jsonrpc': '2.0',
          'result': {
            'params': {'param': 'value'}
          },
          'id': 1234
        })));
  });

  test("calls a method that takes no parameters", () {
    controller.server.registerMethod('foo', () => 'foo');

    expect(
        controller
            .handleRequest({'jsonrpc': '2.0', 'method': 'foo', 'id': 1234}),
        completion(equals({'jsonrpc': '2.0', 'result': 'foo', 'id': 1234})));
  });

  test("a method that takes no parameters rejects parameters", () {
    controller.server.registerMethod('foo', () => 'foo');

    expectErrorResponse(
        controller,
        {'jsonrpc': '2.0', 'method': 'foo', 'params': {}, 'id': 1234},
        error_code.INVALID_PARAMS,
        'No parameters are allowed for method "foo".');
  });

  test("an unexpected error in a method is captured", () {
    controller.server
        .registerMethod('foo', () => throw new FormatException('bad format'));

    expect(
        controller
            .handleRequest({'jsonrpc': '2.0', 'method': 'foo', 'id': 1234}),
        completion({
          'jsonrpc': '2.0',
          'id': 1234,
          'error': {
            'code': error_code.SERVER_ERROR,
            'message': 'bad format',
            'data': {
              'request': {'jsonrpc': '2.0', 'method': 'foo', 'id': 1234},
              'full': 'FormatException: bad format',
              'stack': new TypeMatcher<String>()
            }
          }
        }));
  });

  test("doesn't return a result for a notification", () {
    controller.server.registerMethod('foo', (args) => 'result');

    expect(
        controller
            .handleRequest({'jsonrpc': '2.0', 'method': 'foo', 'params': {}}),
        doesNotComplete);
  });

  test("includes the error data in the response", () {
    controller.server.registerMethod('foo', (params) {
      throw new json_rpc.RpcException(5, 'Error message.', data: 'data value');
    });

    expectErrorResponse(
        controller,
        {'jsonrpc': '2.0', 'method': 'foo', 'params': {}, 'id': 1234},
        5,
        'Error message.',
        data: 'data value');
  });

  test("a JSON parse error is rejected", () {
    return controller.handleJsonRequest('invalid json {').then((result) {
      expect(jsonDecode(result), {
        'jsonrpc': '2.0',
        'error': {
          'code': error_code.PARSE_ERROR,
          'message': startsWith("Invalid JSON: "),
          // TODO(nweiz): Always expect the source when sdk#25655 is fixed.
          'data': {
            'request': anyOf([isNull, 'invalid json {'])
          }
        },
        'id': null
      });
    });
  });

  group("fallbacks", () {
    test("calls a fallback if no method matches", () {
      controller.server
        ..registerMethod('foo', () => 'foo')
        ..registerMethod('bar', () => 'foo')
        ..registerFallback((params) => {'fallback': params.value});

      expect(
          controller.handleRequest({
            'jsonrpc': '2.0',
            'method': 'baz',
            'params': {'param': 'value'},
            'id': 1234
          }),
          completion(equals({
            'jsonrpc': '2.0',
            'result': {
              'fallback': {'param': 'value'}
            },
            'id': 1234
          })));
    });

    test("calls the first matching fallback", () {
      controller.server
        ..registerFallback((params) =>
            throw new json_rpc.RpcException.methodNotFound(params.method))
        ..registerFallback((params) => 'fallback 2')
        ..registerFallback((params) => 'fallback 3');

      expect(
          controller.handleRequest(
              {'jsonrpc': '2.0', 'method': 'fallback 2', 'id': 1234}),
          completion(
              equals({'jsonrpc': '2.0', 'result': 'fallback 2', 'id': 1234})));
    });

    test("an unexpected error in a fallback is captured", () {
      controller.server
          .registerFallback((_) => throw new FormatException('bad format'));

      expect(
          controller
              .handleRequest({'jsonrpc': '2.0', 'method': 'foo', 'id': 1234}),
          completion({
            'jsonrpc': '2.0',
            'id': 1234,
            'error': {
              'code': error_code.SERVER_ERROR,
              'message': 'bad format',
              'data': {
                'request': {'jsonrpc': '2.0', 'method': 'foo', 'id': 1234},
                'full': 'FormatException: bad format',
                'stack': new TypeMatcher<String>()
              }
            }
          }));
    });
  });

  test("disallows multiple methods with the same name", () {
    controller.server.registerMethod('foo', () => null);
    expect(() => controller.server.registerMethod('foo', () => null),
        throwsArgumentError);
  });
}