Modified unittest to use new argument syntax.

pkg/unittest/expect.dart

 // Copyright (c) 2012, 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.
 
+part of unittest;
+
 /**
  * This is the main assertion function. It asserts that [actual]
- * matches the [matcher]. [matcher] is optional and defaults to isTrue,
- * so expect can be used with a single predicate argument. [reason]
- * is optional and is typically not supplied if a reasonable matcher is
- * explicitly provided, as a reason can be generated from the matcher.
- * If [reason] is included it is appended to the reason generated
- * by the matcher.
+ * matches the [matcher]. [reason] is optional and is typically not
+ * supplied, as a reason is generated from the matcher; if [reason]
+ * is included it is appended to the reason generated by the matcher.
  *
  * [matcher] can be a value in which case it will be wrapped in an
  * [equals] matcher.
  *
  * If the assertion fails, then the default behavior is to throw an
  * [ExpectException], but this behavior can be changed by calling
  * [configureExpectFailureHandler] and providing an alternative handler that
  * implements the [IFailureHandler] interface. It is also possible to
  * pass a [failureHandler] to [expect] as a final parameter for fine-
  * grained control.
  *
  * In some cases extra diagnostic info can be produced on failure (for
  * example, stack traces on mismatched exceptions). To enable these,
  * [verbose] should be specified as true;
  *
  * expect() is a 3rd generation assertion mechanism, drawing
  * inspiration from [Hamcrest] and Ladislav Thon's [dart-matchers]
  * library.
  *
  * See [Hamcrest] http://en.wikipedia.org/wiki/Hamcrest
  *     [Hamcrest] http://code.google.com/p/hamcrest/
  *     [dart-matchers] https://github.com/Ladicek/dart-matchers
  */
-void expect(actual, [matcher = isTrue, String reason = null,
-            FailureHandler failureHandler = null,
-            bool verbose = false]) {
+void expect(actual, matcher, {String reason, FailureHandler failureHandler,
+            bool verbose : false}) {
   matcher = wrapMatcher(matcher);
   bool doesMatch;
   var matchState = new MatchState();
   try {
     doesMatch = matcher.matches(actual, matchState);
   } catch (e, trace) {
     doesMatch = false;
     if (reason == null) {
       reason = '${(e is String) ? e : e.toString()} at $trace';
     }
@@ skipping 88 matching lines @@
  * formatter is returned; this allows custom expect handlers to easily
  * get a reference to the default formatter.
  */
 ErrorFormatter configureExpectFormatter([ErrorFormatter formatter = null]) {
   if (formatter == null) {
     formatter = _defaultErrorFormatter;
   }
   return _assertErrorFormatter = formatter;
 }