/*
 * Copyright (C) 2011 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "wtf/HashMap.h"

#include "testing/gtest/include/gtest/gtest.h"
#include "wtf/PassRefPtr.h"
#include "wtf/PtrUtil.h"
#include "wtf/RefCounted.h"
#include "wtf/Vector.h"
#include <memory>

namespace WTF {

namespace {

using IntHashMap = HashMap<int, int>;

TEST(HashMapTest, IteratorComparison) {
  IntHashMap map;
  map.add(1, 2);
  EXPECT_TRUE(map.begin() != map.end());
  EXPECT_FALSE(map.begin() == map.end());

  IntHashMap::const_iterator begin = map.begin();
  EXPECT_TRUE(begin == map.begin());
  EXPECT_TRUE(map.begin() == begin);
  EXPECT_TRUE(begin != map.end());
  EXPECT_TRUE(map.end() != begin);
  EXPECT_FALSE(begin != map.begin());
  EXPECT_FALSE(map.begin() != begin);
  EXPECT_FALSE(begin == map.end());
  EXPECT_FALSE(map.end() == begin);
}

struct TestDoubleHashTraits : HashTraits<double> {
  static const unsigned minimumTableSize = 8;
};

using DoubleHashMap =
    HashMap<double, int64_t, DefaultHash<double>::Hash, TestDoubleHashTraits>;

int bucketForKey(double key) {
  return DefaultHash<double>::Hash::hash(key) &
         (TestDoubleHashTraits::minimumTableSize - 1);
}

TEST(HashMapTest, DoubleHashCollisions) {
  // The "clobber" key here is one that ends up stealing the bucket that the -0
  // key originally wants to be in. This makes the 0 and -0 keys collide and
  // the test then fails unless the FloatHash::equals() implementation can
  // distinguish them.
  const double clobberKey = 6;
  const double zeroKey = 0;
  const double negativeZeroKey = -zeroKey;

  DoubleHashMap map;

  map.add(clobberKey, 1);
  map.add(zeroKey, 2);
  map.add(negativeZeroKey, 3);

  EXPECT_EQ(bucketForKey(clobberKey), bucketForKey(negativeZeroKey));
  EXPECT_EQ(1, map.get(clobberKey));
  EXPECT_EQ(2, map.get(zeroKey));
  EXPECT_EQ(3, map.get(negativeZeroKey));
}

class DestructCounter {
 public:
  explicit DestructCounter(int i, int* destructNumber)
      : m_i(i), m_destructNumber(destructNumber) {}

  ~DestructCounter() { ++(*m_destructNumber); }
  int get() const { return m_i; }

 private:
  int m_i;
  int* m_destructNumber;
};

using OwnPtrHashMap = HashMap<int, std::unique_ptr<DestructCounter>>;

TEST(HashMapTest, OwnPtrAsValue) {
  int destructNumber = 0;
  OwnPtrHashMap map;
  map.add(1, WTF::wrapUnique(new DestructCounter(1, &destructNumber)));
  map.add(2, WTF::wrapUnique(new DestructCounter(2, &destructNumber)));

  DestructCounter* counter1 = map.get(1);
  EXPECT_EQ(1, counter1->get());
  DestructCounter* counter2 = map.get(2);
  EXPECT_EQ(2, counter2->get());
  EXPECT_EQ(0, destructNumber);

  for (OwnPtrHashMap::iterator iter = map.begin(); iter != map.end(); ++iter) {
    std::unique_ptr<DestructCounter>& ownCounter = iter->value;
    EXPECT_EQ(iter->key, ownCounter->get());
  }
  ASSERT_EQ(0, destructNumber);

  std::unique_ptr<DestructCounter> ownCounter1 = map.take(1);
  EXPECT_EQ(ownCounter1.get(), counter1);
  EXPECT_FALSE(map.contains(1));
  EXPECT_EQ(0, destructNumber);

  map.remove(2);
  EXPECT_FALSE(map.contains(2));
  EXPECT_EQ(0UL, map.size());
  EXPECT_EQ(1, destructNumber);

  ownCounter1.reset();
  EXPECT_EQ(2, destructNumber);
}

class DummyRefCounted : public RefCounted<DummyRefCounted> {
 public:
  DummyRefCounted(bool& isDeleted) : m_isDeleted(isDeleted) {
    m_isDeleted = false;
  }
  ~DummyRefCounted() {
    DCHECK(!m_isDeleted);
    m_isDeleted = true;
  }

  void ref() {
    DCHECK(!m_isDeleted);
    WTF::RefCounted<DummyRefCounted>::ref();
    ++m_refInvokesCount;
  }

  void deref() {
    DCHECK(!m_isDeleted);
    WTF::RefCounted<DummyRefCounted>::deref();
  }

  static int m_refInvokesCount;

 private:
  bool& m_isDeleted;
};

int DummyRefCounted::m_refInvokesCount = 0;

TEST(HashMapTest, RefPtrAsKey) {
  bool isDeleted = false;
  DummyRefCounted::m_refInvokesCount = 0;
  RefPtr<DummyRefCounted> ptr = adoptRef(new DummyRefCounted(isDeleted));
  EXPECT_EQ(0, DummyRefCounted::m_refInvokesCount);
  HashMap<RefPtr<DummyRefCounted>, int> map;
  map.add(ptr, 1);
  // Referenced only once (to store a copy in the container).
  EXPECT_EQ(1, DummyRefCounted::m_refInvokesCount);
  EXPECT_EQ(1, map.get(ptr));

  DummyRefCounted* rawPtr = ptr.get();

  EXPECT_TRUE(map.contains(rawPtr));
  EXPECT_NE(map.end(), map.find(rawPtr));
  EXPECT_TRUE(map.contains(ptr));
  EXPECT_NE(map.end(), map.find(ptr));
  EXPECT_EQ(1, DummyRefCounted::m_refInvokesCount);

  ptr.clear();
  EXPECT_FALSE(isDeleted);

  map.remove(rawPtr);
  EXPECT_EQ(1, DummyRefCounted::m_refInvokesCount);
  EXPECT_TRUE(isDeleted);
  EXPECT_TRUE(map.isEmpty());
}

TEST(HashMaptest, RemoveAdd) {
  DummyRefCounted::m_refInvokesCount = 0;
  bool isDeleted = false;

  typedef HashMap<int, RefPtr<DummyRefCounted>> Map;
  Map map;

  RefPtr<DummyRefCounted> ptr = adoptRef(new DummyRefCounted(isDeleted));
  EXPECT_EQ(0, DummyRefCounted::m_refInvokesCount);

  map.add(1, ptr);
  // Referenced only once (to store a copy in the container).
  EXPECT_EQ(1, DummyRefCounted::m_refInvokesCount);
  EXPECT_EQ(ptr, map.get(1));

  ptr.clear();
  EXPECT_FALSE(isDeleted);

  map.remove(1);
  EXPECT_EQ(1, DummyRefCounted::m_refInvokesCount);
  EXPECT_TRUE(isDeleted);
  EXPECT_TRUE(map.isEmpty());

  // Add and remove until the deleted slot is reused.
  for (int i = 1; i < 100; i++) {
    bool isDeleted2 = false;
    RefPtr<DummyRefCounted> ptr2 = adoptRef(new DummyRefCounted(isDeleted2));
    map.add(i, ptr2);
    EXPECT_FALSE(isDeleted2);
    ptr2.clear();
    EXPECT_FALSE(isDeleted2);
    map.remove(i);
    EXPECT_TRUE(isDeleted2);
  }
}

class SimpleClass {
 public:
  explicit SimpleClass(int v) : m_v(v) {}
  int v() { return m_v; }

 private:
  int m_v;
};
using IntSimpleMap = HashMap<int, std::unique_ptr<SimpleClass>>;

TEST(HashMapTest, AddResult) {
  IntSimpleMap map;
  IntSimpleMap::AddResult result = map.add(1, nullptr);
  EXPECT_TRUE(result.isNewEntry);
  EXPECT_EQ(1, result.storedValue->key);
  EXPECT_EQ(0, result.storedValue->value.get());

  SimpleClass* simple1 = new SimpleClass(1);
  result.storedValue->value = WTF::wrapUnique(simple1);
  EXPECT_EQ(simple1, map.get(1));

  IntSimpleMap::AddResult result2 = map.add(1, WTF::makeUnique<SimpleClass>(2));
  EXPECT_FALSE(result2.isNewEntry);
  EXPECT_EQ(1, result.storedValue->key);
  EXPECT_EQ(1, result.storedValue->value->v());
  EXPECT_EQ(1, map.get(1)->v());
}

TEST(HashMapTest, AddResultVectorValue) {
  using IntVectorMap = HashMap<int, Vector<int>>;
  IntVectorMap map;
  IntVectorMap::AddResult result = map.add(1, Vector<int>());
  EXPECT_TRUE(result.isNewEntry);
  EXPECT_EQ(1, result.storedValue->key);
  EXPECT_EQ(0u, result.storedValue->value.size());

  result.storedValue->value.push_back(11);
  EXPECT_EQ(1u, map.find(1)->value.size());
  EXPECT_EQ(11, map.find(1)->value.front());

  IntVectorMap::AddResult result2 = map.add(1, Vector<int>());
  EXPECT_FALSE(result2.isNewEntry);
  EXPECT_EQ(1, result.storedValue->key);
  EXPECT_EQ(1u, result.storedValue->value.size());
  EXPECT_EQ(11, result.storedValue->value.front());
  EXPECT_EQ(11, map.find(1)->value.front());
}

class InstanceCounter {
 public:
  InstanceCounter() { ++counter; }
  InstanceCounter(const InstanceCounter& another) { ++counter; }
  ~InstanceCounter() { --counter; }
  static int counter;
};
int InstanceCounter::counter = 0;

TEST(HashMapTest, ValueTypeDestructed) {
  InstanceCounter::counter = 0;
  HashMap<int, InstanceCounter> map;
  map.set(1, InstanceCounter());
  map.clear();
  EXPECT_EQ(0, InstanceCounter::counter);
}

class MoveOnly {
 public:
  // kEmpty and kDeleted have special meanings when MoveOnly is used as the key
  // of a hash table.
  enum { kEmpty = 0, kDeleted = -1, kMovedOut = -2 };

  explicit MoveOnly(int value = kEmpty) : m_value(value) {}
  MoveOnly(MoveOnly&& other) : m_value(other.m_value) {
    other.m_value = kMovedOut;
  }
  MoveOnly& operator=(MoveOnly&& other) {
    m_value = other.m_value;
    other.m_value = kMovedOut;
    return *this;
  }

  int value() const { return m_value; }

 private:
  MoveOnly(const MoveOnly&) = delete;
  MoveOnly& operator=(const MoveOnly&) = delete;

  int m_value;
};

struct MoveOnlyHashTraits : public GenericHashTraits<MoveOnly> {
  // This is actually true, but we pretend that it's false to disable the
  // optimization.
  static const bool emptyValueIsZero = false;

  static const bool hasIsEmptyValueFunction = true;
  static bool isEmptyValue(const MoveOnly& value) {
    return value.value() == MoveOnly::kEmpty;
  }
  static void constructDeletedValue(MoveOnly& slot, bool) {
    slot = MoveOnly(MoveOnly::kDeleted);
  }
  static bool isDeletedValue(const MoveOnly& value) {
    return value.value() == MoveOnly::kDeleted;
  }
};

struct MoveOnlyHash {
  static unsigned hash(const MoveOnly& value) {
    return DefaultHash<int>::Hash::hash(value.value());
  }
  static bool equal(const MoveOnly& left, const MoveOnly& right) {
    return DefaultHash<int>::Hash::equal(left.value(), right.value());
  }
  static const bool safeToCompareToEmptyOrDeleted = true;
};

}  // anonymous namespace

template <>
struct HashTraits<MoveOnly> : public MoveOnlyHashTraits {};

template <>
struct DefaultHash<MoveOnly> {
  using Hash = MoveOnlyHash;
};

namespace {

TEST(HashMapTest, MoveOnlyValueType) {
  using TheMap = HashMap<int, MoveOnly>;
  TheMap map;
  {
    TheMap::AddResult addResult = map.add(1, MoveOnly(10));
    EXPECT_TRUE(addResult.isNewEntry);
    EXPECT_EQ(1, addResult.storedValue->key);
    EXPECT_EQ(10, addResult.storedValue->value.value());
  }
  auto iter = map.find(1);
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(1, iter->key);
  EXPECT_EQ(10, iter->value.value());

  iter = map.find(2);
  EXPECT_TRUE(iter == map.end());

  // Try to add more to trigger rehashing.
  for (int i = 2; i < 32; ++i) {
    TheMap::AddResult addResult = map.add(i, MoveOnly(i * 10));
    EXPECT_TRUE(addResult.isNewEntry);
    EXPECT_EQ(i, addResult.storedValue->key);
    EXPECT_EQ(i * 10, addResult.storedValue->value.value());
  }

  iter = map.find(1);
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(1, iter->key);
  EXPECT_EQ(10, iter->value.value());

  iter = map.find(7);
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(7, iter->key);
  EXPECT_EQ(70, iter->value.value());

  {
    TheMap::AddResult addResult = map.set(9, MoveOnly(999));
    EXPECT_FALSE(addResult.isNewEntry);
    EXPECT_EQ(9, addResult.storedValue->key);
    EXPECT_EQ(999, addResult.storedValue->value.value());
  }

  map.remove(11);
  iter = map.find(11);
  EXPECT_TRUE(iter == map.end());

  MoveOnly oneThirty(map.take(13));
  EXPECT_EQ(130, oneThirty.value());
  iter = map.find(13);
  EXPECT_TRUE(iter == map.end());

  map.clear();
}

TEST(HashMapTest, MoveOnlyKeyType) {
  // The content of this test is similar to the test above, except that the
  // types of key and value are swapped.
  using TheMap = HashMap<MoveOnly, int>;
  TheMap map;
  {
    TheMap::AddResult addResult = map.add(MoveOnly(1), 10);
    EXPECT_TRUE(addResult.isNewEntry);
    EXPECT_EQ(1, addResult.storedValue->key.value());
    EXPECT_EQ(10, addResult.storedValue->value);
  }
  auto iter = map.find(MoveOnly(1));
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(1, iter->key.value());
  EXPECT_EQ(10, iter->value);

  iter = map.find(MoveOnly(2));
  EXPECT_TRUE(iter == map.end());

  for (int i = 2; i < 32; ++i) {
    TheMap::AddResult addResult = map.add(MoveOnly(i), i * 10);
    EXPECT_TRUE(addResult.isNewEntry);
    EXPECT_EQ(i, addResult.storedValue->key.value());
    EXPECT_EQ(i * 10, addResult.storedValue->value);
  }

  iter = map.find(MoveOnly(1));
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(1, iter->key.value());
  EXPECT_EQ(10, iter->value);

  iter = map.find(MoveOnly(7));
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(7, iter->key.value());
  EXPECT_EQ(70, iter->value);

  {
    TheMap::AddResult addResult = map.set(MoveOnly(9), 999);
    EXPECT_FALSE(addResult.isNewEntry);
    EXPECT_EQ(9, addResult.storedValue->key.value());
    EXPECT_EQ(999, addResult.storedValue->value);
  }

  map.remove(MoveOnly(11));
  iter = map.find(MoveOnly(11));
  EXPECT_TRUE(iter == map.end());

  int oneThirty = map.take(MoveOnly(13));
  EXPECT_EQ(130, oneThirty);
  iter = map.find(MoveOnly(13));
  EXPECT_TRUE(iter == map.end());

  map.clear();
}

class CountCopy final {
 public:
  CountCopy() : m_counter(nullptr) {}
  explicit CountCopy(int& counter) : m_counter(&counter) {}
  CountCopy(const CountCopy& other) : m_counter(other.m_counter) {
    if (m_counter)
      ++*m_counter;
  }
  CountCopy& operator=(const CountCopy& other) {
    m_counter = other.m_counter;
    if (m_counter)
      ++*m_counter;
    return *this;
  }

 private:
  int* m_counter;
};

TEST(HashMapTest, MoveShouldNotMakeCopy) {
  HashMap<int, CountCopy> map;
  int counter = 0;
  map.add(1, CountCopy(counter));

  HashMap<int, CountCopy> other(map);
  counter = 0;
  map = std::move(other);
  EXPECT_EQ(0, counter);

  counter = 0;
  HashMap<int, CountCopy> yetAnother(std::move(map));
  EXPECT_EQ(0, counter);
}

TEST(HashMapTest, UniquePtrAsKey) {
  using Pointer = std::unique_ptr<int>;
  using Map = HashMap<Pointer, int>;
  Map map;
  int* onePointer = new int(1);
  {
    Map::AddResult addResult = map.add(Pointer(onePointer), 1);
    EXPECT_TRUE(addResult.isNewEntry);
    EXPECT_EQ(onePointer, addResult.storedValue->key.get());
    EXPECT_EQ(1, *addResult.storedValue->key);
    EXPECT_EQ(1, addResult.storedValue->value);
  }
  auto iter = map.find(onePointer);
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(onePointer, iter->key.get());
  EXPECT_EQ(1, iter->value);

  Pointer nonexistent(new int(42));
  iter = map.find(nonexistent.get());
  EXPECT_TRUE(iter == map.end());

  // Insert more to cause a rehash.
  for (int i = 2; i < 32; ++i) {
    Map::AddResult addResult = map.add(Pointer(new int(i)), i);
    EXPECT_TRUE(addResult.isNewEntry);
    EXPECT_EQ(i, *addResult.storedValue->key);
    EXPECT_EQ(i, addResult.storedValue->value);
  }

  iter = map.find(onePointer);
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(onePointer, iter->key.get());
  EXPECT_EQ(1, iter->value);

  EXPECT_EQ(1, map.take(onePointer));
  // From now on, |onePointer| is a dangling pointer.

  iter = map.find(onePointer);
  EXPECT_TRUE(iter == map.end());
}

TEST(HashMapTest, UniquePtrAsValue) {
  using Pointer = std::unique_ptr<int>;
  using Map = HashMap<int, Pointer>;
  Map map;
  {
    Map::AddResult addResult = map.add(1, Pointer(new int(1)));
    EXPECT_TRUE(addResult.isNewEntry);
    EXPECT_EQ(1, addResult.storedValue->key);
    EXPECT_EQ(1, *addResult.storedValue->value);
  }
  auto iter = map.find(1);
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(1, iter->key);
  EXPECT_EQ(1, *iter->value);

  int* onePointer = map.get(1);
  EXPECT_TRUE(onePointer);
  EXPECT_EQ(1, *onePointer);

  iter = map.find(42);
  EXPECT_TRUE(iter == map.end());

  for (int i = 2; i < 32; ++i) {
    Map::AddResult addResult = map.add(i, Pointer(new int(i)));
    EXPECT_TRUE(addResult.isNewEntry);
    EXPECT_EQ(i, addResult.storedValue->key);
    EXPECT_EQ(i, *addResult.storedValue->value);
  }

  iter = map.find(1);
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(1, iter->key);
  EXPECT_EQ(1, *iter->value);

  Pointer one(map.take(1));
  ASSERT_TRUE(one);
  EXPECT_EQ(1, *one);

  Pointer empty(map.take(42));
  EXPECT_TRUE(!empty);

  iter = map.find(1);
  EXPECT_TRUE(iter == map.end());

  {
    Map::AddResult addResult = map.add(1, std::move(one));
    EXPECT_TRUE(addResult.isNewEntry);
    EXPECT_EQ(1, addResult.storedValue->key);
    EXPECT_EQ(1, *addResult.storedValue->value);
  }
}

TEST(HashMapTest, MoveOnlyPairKeyType) {
  using Pair = std::pair<MoveOnly, int>;
  using TheMap = HashMap<Pair, int>;
  TheMap map;
  {
    TheMap::AddResult addResult = map.add(Pair(MoveOnly(1), -1), 10);
    EXPECT_TRUE(addResult.isNewEntry);
    EXPECT_EQ(1, addResult.storedValue->key.first.value());
    EXPECT_EQ(-1, addResult.storedValue->key.second);
    EXPECT_EQ(10, addResult.storedValue->value);
  }
  auto iter = map.find(Pair(MoveOnly(1), -1));
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(1, iter->key.first.value());
  EXPECT_EQ(-1, iter->key.second);
  EXPECT_EQ(10, iter->value);

  iter = map.find(Pair(MoveOnly(1), 0));
  EXPECT_TRUE(iter == map.end());

  for (int i = 2; i < 32; ++i) {
    TheMap::AddResult addResult = map.add(Pair(MoveOnly(i), -i), i * 10);
    EXPECT_TRUE(addResult.isNewEntry);
    EXPECT_EQ(i, addResult.storedValue->key.first.value());
    EXPECT_EQ(-i, addResult.storedValue->key.second);
    EXPECT_EQ(i * 10, addResult.storedValue->value);
  }

  iter = map.find(Pair(MoveOnly(1), -1));
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(1, iter->key.first.value());
  EXPECT_EQ(-1, iter->key.second);
  EXPECT_EQ(10, iter->value);

  iter = map.find(Pair(MoveOnly(7), -7));
  ASSERT_TRUE(iter != map.end());
  EXPECT_EQ(7, iter->key.first.value());
  EXPECT_EQ(-7, iter->key.second);
  EXPECT_EQ(70, iter->value);

  {
    TheMap::AddResult addResult = map.set(Pair(MoveOnly(9), -9), 999);
    EXPECT_FALSE(addResult.isNewEntry);
    EXPECT_EQ(9, addResult.storedValue->key.first.value());
    EXPECT_EQ(-9, addResult.storedValue->key.second);
    EXPECT_EQ(999, addResult.storedValue->value);
  }

  map.remove(Pair(MoveOnly(11), -11));
  iter = map.find(Pair(MoveOnly(11), -11));
  EXPECT_TRUE(iter == map.end());

  int oneThirty = map.take(Pair(MoveOnly(13), -13));
  EXPECT_EQ(130, oneThirty);
  iter = map.find(Pair(MoveOnly(13), -13));
  EXPECT_TRUE(iter == map.end());

  map.clear();
}

bool isOneTwoThree(const HashMap<int, int>& map) {
  return map.size() == 3 && map.contains(1) && map.contains(2) &&
         map.contains(3) && map.get(1) == 11 && map.get(2) == 22 &&
         map.get(3) == 33;
};

HashMap<int, int> returnOneTwoThree() {
  return {{1, 11}, {2, 22}, {3, 33}};
};

TEST(HashMapTest, InitializerList) {
  HashMap<int, int> empty({});
  EXPECT_TRUE(empty.isEmpty());

  HashMap<int, int> one({{1, 11}});
  EXPECT_EQ(one.size(), 1u);
  EXPECT_TRUE(one.contains(1));
  EXPECT_EQ(one.get(1), 11);

  HashMap<int, int> oneTwoThree({{1, 11}, {2, 22}, {3, 33}});
  EXPECT_EQ(oneTwoThree.size(), 3u);
  EXPECT_TRUE(oneTwoThree.contains(1));
  EXPECT_TRUE(oneTwoThree.contains(2));
  EXPECT_TRUE(oneTwoThree.contains(3));
  EXPECT_EQ(oneTwoThree.get(1), 11);
  EXPECT_EQ(oneTwoThree.get(2), 22);
  EXPECT_EQ(oneTwoThree.get(3), 33);

  // Put some jank so we can check if the assignments can clear them later.
  empty.add(9999, 99999);
  one.add(9999, 99999);
  oneTwoThree.add(9999, 99999);

  empty = {};
  EXPECT_TRUE(empty.isEmpty());

  one = {{1, 11}};
  EXPECT_EQ(one.size(), 1u);
  EXPECT_TRUE(one.contains(1));
  EXPECT_EQ(one.get(1), 11);

  oneTwoThree = {{1, 11}, {2, 22}, {3, 33}};
  EXPECT_EQ(oneTwoThree.size(), 3u);
  EXPECT_TRUE(oneTwoThree.contains(1));
  EXPECT_TRUE(oneTwoThree.contains(2));
  EXPECT_TRUE(oneTwoThree.contains(3));
  EXPECT_EQ(oneTwoThree.get(1), 11);
  EXPECT_EQ(oneTwoThree.get(2), 22);
  EXPECT_EQ(oneTwoThree.get(3), 33);

  // Other ways of construction: as a function parameter and in a return
  // statement.
  EXPECT_TRUE(isOneTwoThree({{1, 11}, {2, 22}, {3, 33}}));
  EXPECT_TRUE(isOneTwoThree(returnOneTwoThree()));
}

}  // anonymous namespace

}  // namespace WTF