Compare sets order-independently in pkg/matcher.

pkg/matcher/test/core_matchers_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.
 
 library matcher.core_matchers_test;
 
 import 'package:matcher/matcher.dart';
 import 'package:unittest/unittest.dart' show test, group;
 
 import 'test_utils.dart';
@@ skipping 29 matching lines @@
     shouldFail(b, same(a), "Expected: same instance as {} Actual: {}");
   });
 
   test('equals', () {
     var a = new Map();
     var b = new Map();
     shouldPass(a, equals(a));
     shouldPass(a, equals(b));
   });
 
+  test('equals with a set', () {
+    var numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10];
+    var set1 = numbers.toSet();
+    numbers.shuffle();
+    var set2 = numbers.toSet();
+
+    shouldPass(set2, equals(set1));
+    shouldPass(numbers, equals(set1));
+    shouldFail([1, 2, 3, 4, 5, 6, 7, 8, 9], equals(set1),
+        "Expected: ?:[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]\n"
+        "  Actual: [1, 2, 3, 4, 5, 6, 7, 8, 9]\n"
+        "   Which: does not contain 10");
+    shouldFail([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11], equals(set1),
+        "Expected: ?:[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]\n"
+        "  Actual: [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]\n"
+        "   Which: larger than expected");
+  });
+
   test('anything', () {
     var a = new Map();
     shouldPass(0, anything);
     shouldPass(null, anything);
     shouldPass(a, anything);
     shouldFail(a, isNot(anything), "Expected: not anything Actual: {}");
   });
 
   test('throws', () {
     shouldFail(doesNotThrow, throws,
@@ skipping 142 matching lines @@
   });
 }
 
 class _Bicycle {
   static final foo = bar();
 
   static bar() {
     return foo + 1;
   }
 }