Fix stack trace chain tests on Windows.

pkg/stack_trace/test/chain_test.dart

 // Copyright (c) 2013, 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 chain_test;
 
 import 'dart:async';
 
+import 'package:path/path.dart' as p;
 import 'package:stack_trace/stack_trace.dart';
 import 'package:unittest/unittest.dart';
 
 import 'utils.dart';
 
 void main() {
   group('capture() with onError catches exceptions', () {
     test('thrown in a microtask', () {
       return captureFuture(() => inMicrotask(() => throw 'error'))
           .then((chain) {
@@ skipping 310 matching lines @@
         equals(new Trace.from(trace).toString()));
   });
 
   test('Chain.parse() parses a real Chain', () {
     return captureFuture(() => inMicrotask(() => throw 'error')).then((chain) {
       expect(new Chain.parse(chain.toString()).toString(),
           equals(chain.toString()));
     });
   });
 
+  var userSlashCode = p.join('user', 'code.dart');
   group('Chain.terse', () {
     test('makes each trace terse', () {
       var chain = new Chain([
         new Trace.parse(
             'dart:core 10:11       Foo.bar\n'
             'dart:core 10:11       Bar.baz\n'
             'user/code.dart 10:11  Bang.qux\n'
             'dart:core 10:11       Zip.zap\n'
             'dart:core 10:11       Zop.zoop'),
         new Trace.parse(
             'user/code.dart 10:11                        Bang.qux\n'
             'dart:core 10:11                             Foo.bar\n'
             'package:stack_trace/stack_trace.dart 10:11  Bar.baz\n'
             'dart:core 10:11                             Zip.zap\n'
             'user/code.dart 10:11                        Zop.zoop')
       ]);
 
       expect(chain.terse.toString(), equals(
           'dart:core             Bar.baz\n'
-          'user/code.dart 10:11  Bang.qux\n'
+          '$userSlashCode 10:11  Bang.qux\n'

[Bob Nystrom, 2013/12/02 22:37:22]

The fact that this is the exact same number of characters is delightful.

           'dart:core             Zop.zoop\n'
           '===== asynchronous gap ===========================\n'
-          'user/code.dart 10:11  Bang.qux\n'
+          '$userSlashCode 10:11  Bang.qux\n'
           'dart:core             Zip.zap\n'
-          'user/code.dart 10:11  Zop.zoop\n'));
+          '$userSlashCode 10:11  Zop.zoop\n'));
     });
 
     test('eliminates internal-only traces', () {
       var chain = new Chain([
         new Trace.parse(
             'user/code.dart 10:11  Foo.bar\n'
             'dart:core 10:11       Bar.baz'),
         new Trace.parse(
             'dart:core 10:11                             Foo.bar\n'
             'package:stack_trace/stack_trace.dart 10:11  Bar.baz\n'
             'dart:core 10:11                             Zip.zap'),
         new Trace.parse(
             'user/code.dart 10:11  Foo.bar\n'
             'dart:core 10:11       Bar.baz')
       ]);
 
       expect(chain.terse.toString(), equals(
-          'user/code.dart 10:11  Foo.bar\n'
+          '$userSlashCode 10:11  Foo.bar\n'
           'dart:core             Bar.baz\n'
           '===== asynchronous gap ===========================\n'
-          'user/code.dart 10:11  Foo.bar\n'
+          '$userSlashCode 10:11  Foo.bar\n'
           'dart:core             Bar.baz\n'));
     });
   });
 
   test('Chain.toTrace eliminates asynchronous gaps', () {
     var trace = new Chain([
       new Trace.parse(
           'user/code.dart 10:11  Foo.bar\n'
           'dart:core 10:11       Bar.baz'),
       new Trace.parse(
           'user/code.dart 10:11  Foo.bar\n'
           'dart:core 10:11       Bar.baz')
     ]).toTrace();
 
     expect(trace.toString(), equals(
-        'user/code.dart 10:11  Foo.bar\n'
+        '$userSlashCode 10:11  Foo.bar\n'
         'dart:core 10:11       Bar.baz\n'
-        'user/code.dart 10:11  Foo.bar\n'
+        '$userSlashCode 10:11  Foo.bar\n'
         'dart:core 10:11       Bar.baz\n'));
   });
 
   group('Chain.track(Future)', () {
     test('associates the current chain with a manually-reported exception with '
         'a stack trace', () {
       var trace = new Trace.current();
       return captureFuture(() {
         inMicrotask(() => trackedErrorFuture(trace));
       }).then((chain) {
@@ skipping 196 matching lines @@
 ///
 /// [callback] is expected to throw the string `"error"`.
 Future<Chain> captureFuture(callback()) {
   var completer = new Completer<Chain>();
   Chain.capture(callback, onError: (error, chain) {
     expect(error, equals('error'));
     completer.complete(chain);
   });
   return completer.future;
 }