Don't throw for unparseable frames.

test/trace_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 trace_test;
 
 import 'package:path/path.dart' as path;
 import 'package:stack_trace/stack_trace.dart';
 import 'package:test/test.dart';
 
@@ skipping 275 matching lines @@
       new Frame(Uri.parse('http://dartlang.org/foo.dart'), null, null, 'bar'),
       new Frame(Uri.parse('dart:async'), 15, null, 'baz'),
     ]);
 
     expect(trace.vmTrace.toString(), equals(
         '#1      Foo.<anonymous closure> ($uri:10:20)\n'
         '#2      bar (http://dartlang.org/foo.dart:0:0)\n'
         '#3      baz (dart:async:15:0)\n'));
   });
 
-  test('.terse folds core frames together bottom-up', () {
-    var trace = new Trace.parse('''
+  group("folding", () {
+    test('.terse folds core frames together bottom-up', () {
+      var trace = new Trace.parse('''
 #1 top (dart:async/future.dart:0:2)
 #2 bottom (dart:core/uri.dart:1:100)
 #0 notCore (foo.dart:42:21)
 #3 top (dart:io:5:10)
 #4 bottom (dart:async-patch/future.dart:9:11)
 #5 alsoNotCore (bar.dart:10:20)
 ''');
 
-    expect(trace.terse.toString(), equals('''
+      expect(trace.terse.toString(), equals('''
 dart:core       bottom
 foo.dart 42:21  notCore
 dart:async      bottom
 bar.dart 10:20  alsoNotCore
 '''));
-  });
+    });
 
-  test('.terse folds empty async frames', () {
-    var trace = new Trace.parse('''
+    test('.terse folds empty async frames', () {
+      var trace = new Trace.parse('''
 #0 top (dart:async/future.dart:0:2)
 #1 empty.<<anonymous closure>_async_body> (bar.dart)
 #2 bottom (dart:async-patch/future.dart:9:11)
 #3 notCore (foo.dart:42:21)
 ''');
 
-    expect(trace.terse.toString(), equals('''
+      expect(trace.terse.toString(), equals('''
 dart:async      bottom
 foo.dart 42:21  notCore
 '''));
-  });
+    });
 
-  test('.terse removes the bottom-most async frame', () {
-    var trace = new Trace.parse('''
+    test('.terse removes the bottom-most async frame', () {
+      var trace = new Trace.parse('''
 #0 notCore (foo.dart:42:21)
 #1 top (dart:async/future.dart:0:2)
 #2 bottom (dart:core/uri.dart:1:100)
 #3 top (dart:io:5:10)
 #4 bottom (dart:async-patch/future.dart:9:11)
 ''');
 
-    expect(trace.terse.toString(), equals('''
+      expect(trace.terse.toString(), equals('''
 foo.dart 42:21  notCore
 '''));
-  });
+    });
 
-  test(".terse won't make a trace empty", () {
-    var trace = new Trace.parse('''
+    test(".terse won't make a trace empty", () {
+      var trace = new Trace.parse('''
 #1 top (dart:async/future.dart:0:2)
 #2 bottom (dart:core/uri.dart:1:100)
 ''');
 
-    expect(trace.terse.toString(), equals('''
+      expect(trace.terse.toString(), equals('''
 dart:core  bottom
 '''));
-  });
+    });
 
-  test(".terse won't panic on an empty trace", () {
-    var trace = new Trace.parse('''
-''');
+    test(".terse won't panic on an empty trace", () {
+      expect(Trace.parse("").terse.toString(), equals(""));
+    });
 
-    expect(trace.terse.toString(), equals('''
-'''));
-  });
-
-  test('.foldFrames folds frames together bottom-up', () {
-    var trace = new Trace.parse('''
+    test('.foldFrames folds frames together bottom-up', () {
+      var trace = new Trace.parse('''
 #0 notFoo (foo.dart:42:21)
 #1 fooTop (bar.dart:0:2)
 #2 fooBottom (foo.dart:1:100)
 #3 alsoNotFoo (bar.dart:10:20)
 #4 fooTop (dart:io/socket.dart:5:10)
 #5 fooBottom (dart:async-patch/future.dart:9:11)
 ''');
 
-    var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'));
-    expect(folded.toString(), equals('''
+      var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'));
+      expect(folded.toString(), equals('''
 foo.dart 42:21                     notFoo
 foo.dart 1:100                     fooBottom
 bar.dart 10:20                     alsoNotFoo
 dart:async-patch/future.dart 9:11  fooBottom
 '''));
-  });
+    });
 
-  test('.foldFrames with terse: true folds core frames as well', () {
-    var trace = new Trace.parse('''
+    test('.foldFrames with terse: true folds core frames as well', () {
+      var trace = new Trace.parse('''
 #0 notFoo (foo.dart:42:21)
 #1 fooTop (bar.dart:0:2)
 #2 coreBottom (dart:async/future.dart:0:2)
 #3 alsoNotFoo (bar.dart:10:20)
 #4 fooTop (foo.dart:9:11)
 #5 coreBottom (dart:async-patch/future.dart:9:11)
 ''');
 
-    var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'),
-        terse: true);
-    expect(folded.toString(), equals('''
+      var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'),
+          terse: true);
+      expect(folded.toString(), equals('''
 foo.dart 42:21  notFoo
 dart:async      coreBottom
 bar.dart 10:20  alsoNotFoo
 '''));
-  });
+    });
 
-  test('.foldFrames with terse: true shortens folded frames', () {
-    var trace = new Trace.parse('''
+    test('.foldFrames with terse: true shortens folded frames', () {
+      var trace = new Trace.parse('''
 #0 notFoo (foo.dart:42:21)
 #1 fooTop (bar.dart:0:2)
 #2 fooBottom (package:foo/bar.dart:0:2)
 #3 alsoNotFoo (bar.dart:10:20)
 #4 fooTop (foo.dart:9:11)
 #5 fooBottom (foo/bar.dart:9:11)
 ''');
 
-    var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'),
-        terse: true);
-    expect(folded.toString(), equals('''
+      var folded = trace.foldFrames((frame) => frame.member.startsWith('foo'),
+          terse: true);
+      expect(folded.toString(), equals('''
 foo.dart 42:21  notFoo
 package:foo     fooBottom
 bar.dart 10:20  alsoNotFoo
 foo             fooBottom
 '''));
+    });
+
+    test('.foldFrames will never fold unparsed frames', () {
+      var trace = new Trace.parse(r'''
+.g"cs$#:b";a#>sw{*{ul$"$xqwr`p
+%+j-?uppx<([j@#nu{{>*+$%x-={`{
+!e($b{nj)zs?cgr%!;bmw.+$j+pfj~
+''');
+
+      expect(trace.foldFrames((frame) => true).toString(), equals(r'''
+.g"cs$#:b";a#>sw{*{ul$"$xqwr`p
+%+j-?uppx<([j@#nu{{>*+$%x-={`{
+!e($b{nj)zs?cgr%!;bmw.+$j+pfj~
+'''));
+    });
   });
 }