Add extra information to FormatException.

pkg/json_rpc_2/test/server/parameters_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.
 
 library json_rpc_2.test.server.parameters_test;
 
 import 'package:unittest/unittest.dart';
 import 'package:json_rpc_2/json_rpc_2.dart' as json_rpc;
 
 import 'utils.dart';
@@ skipping 211 matching lines @@
 
     test("[].asDateTime fails for non-date/time parameters", () {
       expect(() => parameters['int'].asDateTime,
           throwsInvalidParams('Parameter "int" for method "foo" must be a '
               'string, but was 1.'));
     });
 
     test("[].asDateTime fails for invalid date/times", () {
       expect(() => parameters['string'].asDateTime,
           throwsInvalidParams('Parameter "string" for method "foo" must be a '
-              'valid date/time, but was "zap".'));
+              'valid date/time, but was "zap".\n'
+              'Invalid date format'));
     });
 
     test("[].asUri returns URI parameters", () {
       expect(parameters['uri'].asUri, equals(Uri.parse('http://dartlang.org')));
     });
 
     test("[].asUriOr returns URI parameters", () {
       expect(parameters['uri'].asUriOr(Uri.parse('http://google.com')),
           equals(Uri.parse('http://dartlang.org')));
     });
@@ skipping 12 matching lines @@
     test("[].asUri fails for non-URI parameters", () {
       expect(() => parameters['int'].asUri,
           throwsInvalidParams('Parameter "int" for method "foo" must be a '
               'string, but was 1.'));
     });
 
     test("[].asUri fails for invalid URIs", () {
       expect(() => parameters['invalid-uri'].asUri,
           throwsInvalidParams('Parameter "invalid-uri" for method "foo" must '
               'be a valid URI, but was "http://[::1".\n'
-              'Missing end `]` to match `[` in host at position 7.\n'
-              'http://[::1\n'
-              '       ^'));
+              'Missing end `]` to match `[` in host'));
     });
 
     group("with a nested parameter map", () {
       var nested;
       setUp(() => nested = parameters['map']);
 
       test("[int] fails with a type error", () {
         expect(() => nested[0],
             throwsInvalidParams('Parameter "map" for method "foo" must be an '
                 'Array, but was {"num":4.2,"bool":false}.'));
@@ skipping 90 matching lines @@
   test("with a complex parameter path", () {
     var parameters = new json_rpc.Parameters("foo", {
       'bar baz': [0, 1, 2, {'bang.zap': {'\n': 'qux'}}]
     });
 
     expect(() => parameters['bar baz'][3]['bang.zap']['\n']['bip'],
         throwsInvalidParams('Parameter "bar baz"[3]."bang.zap"."\\n" for '
             'method "foo" must be an Object, but was "qux".'));
   });
 }