Change package scheduled_test to throw TestFailures rather than strings.

pkg/scheduled_test/lib/src/descriptor/pattern_descriptor.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 descriptor.pattern;
 
 import 'dart:async';
 import 'dart:io';
 
 import 'package:path/path.dart' as path;
@@ skipping 37 matching lines @@
   Future validateNow([String parent]) {
     if (parent == null) parent = defaultRoot;
     // TODO(nweiz): make sure this works with symlinks.
     var matchingEntries = new Directory(parent).listSync()
         .map((entry) => entry is File ? entry.fullPathSync() : entry.path)
         .where((entry) => fullMatch(path.basename(entry), pattern))
         .toList();
     matchingEntries.sort();
 
     if (matchingEntries.isEmpty) {
-      throw "No entry found in '$parent' matching ${_patternDescription}.";
+      fail("No entry found in '$parent' matching ${_patternDescription}.");
     }
 
     return Future.wait(matchingEntries.map((entry) {
       var descriptor = _fn(path.basename(entry));
       return descriptor.validateNow(parent).then((_) {
         return new Pair(null, descriptor.describe());
       }).catchError((error) {
         return new Pair(error.toString(), descriptor.describe());
       });
     })).then((results) {
       var matches = results.where((result) => result.first == null).toList();
       // If exactly one entry matching [pattern] validated, we're happy.
       if (matches.length == 1) return;
 
       // If more than one entry matching [pattern] validated, that's bad.
       if (matches.length > 1) {
         var resultString = matches.map((result) {
           return prefixLines(result.last, firstPrefix: '* ', prefix: '  ');
         }).join('\n');
 
-        throw "Multiple valid entries found in '$parent' matching "
-                "$_patternDescription:\n"
-            "$resultString";
+        fail("Multiple valid entries found in '$parent' matching "
+             "$_patternDescription:\n"
+             "$resultString");
       }
 
       // If no entries matching [pattern] validated, that's also bad.
       var resultString = results.map((result) {
         return prefixLines(
             "Caught error\n"
             "${prefixLines(result.first)}\n"
             "while validating\n"
             "${prefixLines(result.last)}",
             firstPrefix: '* ', prefix: '  ');
       }).join('\n');
 
-      throw "No valid entries found in '$parent' matching "
-              "$_patternDescription:\n"
-          "$resultString";
+      fail("No valid entries found in '$parent' matching "
+           "$_patternDescription:\n"
+           "$resultString");
     });
   }
 
   String describe() => "entry matching $_patternDescription";
 
   String get _patternDescription {
     if (pattern is String) return "'$pattern'";
     if (pattern is! RegExp) return '$pattern';
 
     var regExp = pattern as RegExp;
     var flags = new StringBuffer();
     if (!regExp.isCaseSensitive) flags.write('i');
     if (regExp.isMultiLine) flags.write('m');
     return '/${regExp.pattern}/$flags';
   }
 
   Future create([String parent]) => new Future.error(
       new UnsupportedError("Pattern descriptors don't support create()."));
 }