Don't throw for unparseable frames.

test/trace_test.dart

Index: test/trace_test.dart
diff --git a/test/trace_test.dart b/test/trace_test.dart
index 14e1e2bd1c5066c2fc4230a95df2afd25e86a46b..1cc32f7ccacf4390cf8a87f50a91c331bc9ffea4 100644
--- a/test/trace_test.dart
+++ b/test/trace_test.dart
@@ -293,8 +293,9 @@ http://pub.dartlang.org/thing.dart 1:100  zip.<fn>.zap
         '#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)
@@ -303,30 +304,30 @@ http://pub.dartlang.org/thing.dart 1:100  zip.<fn>.zap
 #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)
@@ -334,32 +335,28 @@ foo.dart 42:21  notCore
 #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('''
-''');
+    });
 
-    expect(trace.terse.toString(), equals('''
-'''));
-  });
+    test(".terse won't panic on an empty trace", () {
+      expect(Trace.parse("").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)
@@ -368,17 +365,17 @@ dart:core  bottom
 #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)
@@ -387,17 +384,17 @@ dart:async-patch/future.dart 9:11  fooBottom
 #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)
@@ -406,13 +403,28 @@ bar.dart 10:20  alsoNotFoo
 #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~
+'''));
+    });
   });
 }