Add isNotEmpty to core_matchers.

pkg/matcher/test/matchers_unminified_test.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.
 
 // This file is for matcher tests that rely on the names of various Dart types.
 // These tests will fail when run in minified dart2js, since the names will be
 // mangled. A version of this file that works in minified dart2js is in
 // matchers_minified_test.dart.
 
 library matcher.unminified_test;
@@ skipping 90 matching lines @@
 
   group('Iterable Matchers', () {
     test('isEmpty', () {
       var d = new SimpleIterable(0);
       var e = new SimpleIterable(1);
       shouldPass(d, isEmpty);
       shouldFail(e, isEmpty, "Expected: empty "
           "Actual: SimpleIterable:[1]");
     });
 
+    test('isNotEmpty', () {
+      var d = new SimpleIterable(0);
+      var e = new SimpleIterable(1);
+      shouldPass(e, isNotEmpty);
+      shouldFail(d, isNotEmpty, "Expected: non-empty "
+          "Actual: SimpleIterable:[]");
+    });
+
+
     test('contains', () {
       var d = new SimpleIterable(3);
       shouldPass(d, contains(2));
       shouldFail(d, contains(5),
           "Expected: contains <5> "
           "Actual: SimpleIterable:[3, 2, 1]");
     });
   });
 
   group('Feature Matchers', () {
     test("Feature Matcher", () {
       var w = new Widget();
       w.price = 10;
       shouldPass(w, new HasPrice(10));
       shouldPass(w, new HasPrice(greaterThan(0)));
       shouldFail(w, new HasPrice(greaterThan(10)),
           "Expected: Widget with a price that is a value greater than <10> "
           "Actual: <Instance of 'Widget'> "
           "Which: has price with value <10> which is not "
           "a value greater than <10>");
     });
   });
 }