components/enhanced_bookmarks/item_position_unittest.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "components/enhanced_bookmarks/item_position.h"
   6
   7 #include "testing/gtest/include/gtest/gtest.h"
   8
   9 using enhanced_bookmarks::ItemPosition;
  10
  11 namespace {
  12
  13 class ItemPositionTest : public testing::Test {};
  14
  15 TEST_F(ItemPositionTest, TestCreateBefore) {
  16   ItemPosition current = ItemPosition::CreateInitialPosition();
  17   for (int i = 0; i < 10000; i++) {
  18     ItemPosition next = ItemPosition::CreateBefore(current);
  19     EXPECT_LT(next.ToString(), current.ToString());
  20     current = next;
  21   }
  22   // Make sure string lengths stay reasonable.
  23   EXPECT_LT(current.ToString().size(), 20u);
  24 }
  25
  26 TEST_F(ItemPositionTest, TestCreateAfter) {
  27   ItemPosition current = ItemPosition::CreateInitialPosition();
  28   for (int i = 0; i < 10000; i++) {
  29     ItemPosition next = ItemPosition::CreateAfter(current);
  30     EXPECT_GT(next.ToString(), current.ToString());
  31     current = next;
  32   }
  33   // Make sure string lengths stay reasonable.
  34   EXPECT_LT(current.ToString().size(), 20u);
  35 }
  36
  37 TEST_F(ItemPositionTest, TestCreateBetweenLeftBias) {
  38   ItemPosition before = ItemPosition::CreateInitialPosition();
  39   ItemPosition after = ItemPosition::CreateAfter(before);
  40   for (int i = 0; i < 10000; i++) {
  41     ItemPosition next = ItemPosition::CreateBetween(before, after);
  42     EXPECT_GT(next.ToString(), before.ToString());
  43     EXPECT_LT(next.ToString(), after.ToString());
  44     after = next;
  45   }
  46   // Make sure string lengths stay reasonable.
  47   EXPECT_LT(after.ToString().size(), 20u);
  48 }
  49
  50 TEST_F(ItemPositionTest, TestCreateBetweenRightBias) {
  51   ItemPosition before = ItemPosition::CreateInitialPosition();
  52   ItemPosition after = ItemPosition::CreateAfter(before);
  53   for (int i = 0; i < 10000; i++) {
  54     ItemPosition next = ItemPosition::CreateBetween(before, after);
  55     EXPECT_GT(next.ToString(), before.ToString());
  56     EXPECT_LT(next.ToString(), after.ToString());
  57     before = next;
  58   }
  59   // Make sure string lengths stay reasonable.
  60   EXPECT_LT(before.ToString().size(), 20u);
  61 }
  62
  63 TEST_F(ItemPositionTest, TestCreateBetweenAlternating) {
  64   ItemPosition before = ItemPosition::CreateInitialPosition();
  65   ItemPosition after = ItemPosition::CreateAfter(before);
  66   for (int i = 0; i < 1000; i++) {
  67     ItemPosition next = ItemPosition::CreateBetween(before, after);
  68     EXPECT_GT(next.ToString(), before.ToString());
  69     EXPECT_LT(next.ToString(), after.ToString());
  70     if ((i & 1) == 1)
  71       before = next;
  72     else
  73       after = next;
  74   }
  75   // There's no way to keep the string length down for all possible insertion
  76   // scenarios, and this one should be fairly rare in practice. Still verify
  77   // that at least the growth is restricted to about n*log_2(kPositionBase).
  78   EXPECT_LT(before.ToString().size(), 200u);
  79 }
  80
  81 }  // namespace