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packages/usage/test/uuid_test.dart

+// Copyright (c) 2014, 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 usage.uuid_test;
+
+import 'package:unittest/unittest.dart';
+import 'package:usage/src/uuid.dart';
+
+void defineTests() {
+  group('uuid', () {
+    // xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
+    test('simple', () {
+      Uuid uuid = new Uuid();
+      String result = uuid.generateV4();
+      expect(result.length, 36);
+      expect(result[8], '-');
+      expect(result[13], '-');
+      expect(result[18], '-');
+      expect(result[23], '-');
+    });
+
+    test('can parse', () {
+      Uuid uuid = new Uuid();
+      String result = uuid.generateV4();
+      expect(int.parse(result.substring(0, 8), radix: 16), isNotNull);
+      expect(int.parse(result.substring(9, 13), radix: 16), isNotNull);
+      expect(int.parse(result.substring(14, 18), radix: 16), isNotNull);
+      expect(int.parse(result.substring(19, 23), radix: 16), isNotNull);
+      expect(int.parse(result.substring(24, 36), radix: 16), isNotNull);
+    });
+
+    test('special bits', () {
+      Uuid uuid = new Uuid();
+      String result = uuid.generateV4();
+      expect(result[14], '4');
+      expect(result[19].toLowerCase(), isIn('89ab'));
+
+      result = uuid.generateV4();
+      expect(result[19].toLowerCase(), isIn('89ab'));
+
+      result = uuid.generateV4();
+      expect(result[19].toLowerCase(), isIn('89ab'));
+    });
+
+    test('is pretty random', () {
+      Set set = new Set();
+
+      Uuid uuid = new Uuid();
+      for (int i = 0; i < 64; i++) {
+        String val = uuid.generateV4();
+        expect(set, isNot(contains(val)));
+        set.add(val);
+      }
+
+      uuid = new Uuid();
+      for (int i = 0; i < 64; i++) {
+        String val = uuid.generateV4();
+        expect(set, isNot(contains(val)));
+        set.add(val);
+      }
+
+      uuid = new Uuid();
+      for (int i = 0; i < 64; i++) {
+        String val = uuid.generateV4();
+        expect(set, isNot(contains(val)));
+        set.add(val);
+      }
+    });
+  });
+}