Updated contains and isEmpty matches to use iterables.

pkg/unittest/lib/src/core_matchers.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 matcher;
 
 /**
- * Returns a matcher that matches empty strings, maps or collections.
+ * Returns a matcher that matches empty strings, maps or iterables
+ * (including collections).
  */
 const Matcher isEmpty = const _Empty();
 
 class _Empty extends BaseMatcher {
   const _Empty();
   bool matches(item, MatchState matchState) {
-    if (item is Map || item is Collection) {
+    if (item is Map || item is Iterable) {
       return item.isEmpty;
     } else if (item is String) {
       return item.length == 0;
     } else {
       return false;
     }
   }
   Description describe(Description description) =>
       description.add('empty');
 }
@@ skipping 539 matching lines @@
       }
     } catch (e) {
       return mismatchDescription.add(' has no length property');
     }
   }
 }
 
 /**
  * Returns a matcher that matches if the match argument contains
  * the expected value. For [String]s this means substring matching;
- * for [Map]s is means the map has the key, and for [Collection]s it
- * means the collection has a matching element. In the case of collections,
- * [expected] can itself be a matcher.
+ * for [Map]s it means the map has the key, and for [Iterable]s
+ * (including [Collection]s) it means the iterable has a matching
+ * element. In the case of iterables, [expected] can itself be a
+ * matcher.
  */
 Matcher contains(expected) => new _Contains(expected);
 
 class _Contains extends BaseMatcher {
 
   final _expected;
 
   const _Contains(this._expected);
 
   bool matches(item, MatchState matchState) {
     if (item is String) {
       return item.indexOf(_expected) >= 0;
-    } else if (item is Collection) {
+    } else if (item is Iterable) {
       if (_expected is Matcher) {
         return item.any((e) => _expected.matches(e, matchState));
       } else {
-        return item.any((e) => e == _expected);
+        return item.contains(_expected);
       }
     } else if (item is Map) {
       return item.containsKey(_expected);
     }
     return false;
   }
 
   Description describe(Description description) =>
       description.add('contains ').addDescriptionOf(_expected);
 }
@@ skipping 90 matching lines @@
       description.add(_featureDescription).add(' ').addDescriptionOf(_matcher);
 
   Description describeMismatch(item, Description mismatchDescription,
                                MatchState matchState, bool verbose) {
     mismatchDescription.add(_featureName).add(' ');
     _matcher.describeMismatch(matchState.state['feature'], mismatchDescription,
         matchState.state['innerState'], verbose);
     return mismatchDescription;
   }
 }