pw_varint/varint_test.cc

// Copyright 2019 The Pigweed Authors
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not
// use this file except in compliance with the License. You may obtain a copy of
// the License at
//
//     https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
// WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
// License for the specific language governing permissions and limitations under
// the License.

#include "pw_varint/varint.h"

#include <cinttypes>
#include <cstdint>
#include <cstring>
#include <limits>

#include "gtest/gtest.h"

namespace pw::varint {
namespace {

class Varint : public ::testing::Test {
 protected:
  Varint()
      : buffer_{std::byte{'a'},
                std::byte{'b'},
                std::byte{'c'},
                std::byte{'d'},
                std::byte{'e'},
                std::byte{'f'},
                std::byte{'g'},
                std::byte{'h'},
                std::byte{'i'},
                std::byte{'j'}} {}
  std::byte buffer_[10];
};

TEST_F(Varint, EncodeSizeUnsigned32_SmallSingleByte) {
  ASSERT_EQ(1u, Encode(UINT32_C(0), buffer_));
  EXPECT_EQ(std::byte{0}, buffer_[0]);
  ASSERT_EQ(1u, Encode(UINT32_C(1), buffer_));
  EXPECT_EQ(std::byte{1}, buffer_[0]);
  ASSERT_EQ(1u, Encode(UINT32_C(2), buffer_));
  EXPECT_EQ(std::byte{2}, buffer_[0]);
}

TEST_F(Varint, EncodeSizeUnsigned32_LargeSingleByte) {
  ASSERT_EQ(1u, Encode(UINT32_C(63), buffer_));
  EXPECT_EQ(std::byte{63}, buffer_[0]);
  ASSERT_EQ(1u, Encode(UINT32_C(64), buffer_));
  EXPECT_EQ(std::byte{64}, buffer_[0]);
  ASSERT_EQ(1u, Encode(UINT32_C(126), buffer_));
  EXPECT_EQ(std::byte{126}, buffer_[0]);
  ASSERT_EQ(1u, Encode(UINT32_C(127), buffer_));
  EXPECT_EQ(std::byte{127}, buffer_[0]);
}

TEST_F(Varint, EncodeSizeUnsigned32_MultiByte) {
  ASSERT_EQ(2u, Encode(UINT32_C(128), buffer_));
  EXPECT_EQ(std::memcmp("\x80\x01", buffer_, 2), 0);
  ASSERT_EQ(2u, Encode(UINT32_C(129), buffer_));
  EXPECT_EQ(std::memcmp("\x81\x01", buffer_, 2), 0);

  ASSERT_EQ(5u, Encode(std::numeric_limits<uint32_t>::max() - 1, buffer_));
  EXPECT_EQ(std::memcmp("\xfe\xff\xff\xff\x0f", buffer_, 5), 0);

  ASSERT_EQ(5u, Encode(std::numeric_limits<uint32_t>::max(), buffer_));
  EXPECT_EQ(std::memcmp("\xff\xff\xff\xff\x0f", buffer_, 5), 0);
}

TEST_F(Varint, EncodeSizeSigned32_SmallSingleByte) {
  ASSERT_EQ(1u, Encode(INT32_C(0), buffer_));
  EXPECT_EQ(std::byte{0}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT32_C(-1), buffer_));
  EXPECT_EQ(std::byte{1}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT32_C(1), buffer_));
  EXPECT_EQ(std::byte{2}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT32_C(-2), buffer_));
  EXPECT_EQ(std::byte{3}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT32_C(2), buffer_));
  EXPECT_EQ(std::byte{4}, buffer_[0]);
}

TEST_F(Varint, EncodeSizeSigned32_LargeSingleByte) {
  ASSERT_EQ(1u, Encode(INT32_C(-63), buffer_));
  EXPECT_EQ(std::byte{125}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT32_C(63), buffer_));
  EXPECT_EQ(std::byte{126}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT32_C(-64), buffer_));
  EXPECT_EQ(std::byte{127}, buffer_[0]);
}

TEST_F(Varint, EncodeSizeSigned32_MultiByte) {
  ASSERT_EQ(2u, Encode(INT32_C(64), buffer_));
  EXPECT_EQ(std::memcmp("\x80\x01", buffer_, 2), 0);
  ASSERT_EQ(2u, Encode(INT32_C(-65), buffer_));
  EXPECT_EQ(std::memcmp("\x81\x01", buffer_, 2), 0);
  ASSERT_EQ(2u, Encode(INT32_C(65), buffer_));
  EXPECT_EQ(std::memcmp("\x82\x01", buffer_, 2), 0);

  ASSERT_EQ(5u, Encode(std::numeric_limits<int32_t>::min(), buffer_));
  EXPECT_EQ(std::memcmp("\xff\xff\xff\xff\x0f", buffer_, 5), 0);

  ASSERT_EQ(5u, Encode(std::numeric_limits<int32_t>::max(), buffer_));
  EXPECT_EQ(std::memcmp("\xfe\xff\xff\xff\x0f", buffer_, 5), 0);
}

TEST_F(Varint, EncodeSizeUnsigned64_SmallSingleByte) {
  ASSERT_EQ(1u, Encode(UINT64_C(0), buffer_));
  EXPECT_EQ(std::byte{0}, buffer_[0]);
  ASSERT_EQ(1u, Encode(UINT64_C(1), buffer_));
  EXPECT_EQ(std::byte{1}, buffer_[0]);
  ASSERT_EQ(1u, Encode(UINT64_C(2), buffer_));
  EXPECT_EQ(std::byte{2}, buffer_[0]);
}

TEST_F(Varint, EncodeSizeUnsigned64_LargeSingleByte) {
  ASSERT_EQ(1u, Encode(UINT64_C(63), buffer_));
  EXPECT_EQ(std::byte{63}, buffer_[0]);
  ASSERT_EQ(1u, Encode(UINT64_C(64), buffer_));
  EXPECT_EQ(std::byte{64}, buffer_[0]);
  ASSERT_EQ(1u, Encode(UINT64_C(126), buffer_));
  EXPECT_EQ(std::byte{126}, buffer_[0]);
  ASSERT_EQ(1u, Encode(UINT64_C(127), buffer_));
  EXPECT_EQ(std::byte{127}, buffer_[0]);
}

TEST_F(Varint, EncodeSizeUnsigned64_MultiByte) {
  ASSERT_EQ(2u, Encode(UINT64_C(128), buffer_));
  EXPECT_EQ(std::memcmp("\x80\x01", buffer_, 2), 0);
  ASSERT_EQ(2u, Encode(UINT64_C(129), buffer_));
  EXPECT_EQ(std::memcmp("\x81\x01", buffer_, 2), 0);

  ASSERT_EQ(5u, Encode(std::numeric_limits<uint32_t>::max() - 1, buffer_));
  EXPECT_EQ(std::memcmp("\xfe\xff\xff\xff\x0f", buffer_, 5), 0);

  ASSERT_EQ(5u, Encode(std::numeric_limits<uint32_t>::max(), buffer_));
  EXPECT_EQ(std::memcmp("\xff\xff\xff\xff\x0f", buffer_, 5), 0);

  ASSERT_EQ(10u, Encode(std::numeric_limits<uint64_t>::max() - 1, buffer_));
  EXPECT_EQ(
      std::memcmp("\xfe\xff\xff\xff\xff\xff\xff\xff\xff\x01", buffer_, 10), 0);

  ASSERT_EQ(10u, Encode(std::numeric_limits<uint64_t>::max(), buffer_));
  EXPECT_EQ(
      std::memcmp("\xff\xff\xff\xff\xff\xff\xff\xff\xff\x01", buffer_, 10), 0);
}

TEST_F(Varint, EncodeSizeSigned64_SmallSingleByte) {
  ASSERT_EQ(1u, Encode(INT64_C(0), buffer_));
  EXPECT_EQ(std::byte{0}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT64_C(-1), buffer_));
  EXPECT_EQ(std::byte{1}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT64_C(1), buffer_));
  EXPECT_EQ(std::byte{2}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT64_C(-2), buffer_));
  EXPECT_EQ(std::byte{3}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT64_C(2), buffer_));
  EXPECT_EQ(std::byte{4}, buffer_[0]);
}

TEST_F(Varint, EncodeSizeSigned64_LargeSingleByte) {
  ASSERT_EQ(1u, Encode(INT64_C(-63), buffer_));
  EXPECT_EQ(std::byte{125}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT64_C(63), buffer_));
  EXPECT_EQ(std::byte{126}, buffer_[0]);
  ASSERT_EQ(1u, Encode(INT64_C(-64), buffer_));
  EXPECT_EQ(std::byte{127}, buffer_[0]);
}

TEST_F(Varint, EncodeSizeSigned64_MultiByte) {
  ASSERT_EQ(2u, Encode(INT64_C(64), buffer_));
  EXPECT_EQ(std::memcmp("\x80\x01", buffer_, 2), 0);
  ASSERT_EQ(2u, Encode(INT64_C(-65), buffer_));
  EXPECT_EQ(std::memcmp("\x81\x01", buffer_, 2), 0);
  ASSERT_EQ(2u, Encode(INT64_C(65), buffer_));
  EXPECT_EQ(std::memcmp("\x82\x01", buffer_, 2), 0);

  ASSERT_EQ(5u,
            Encode(static_cast<int64_t>(std::numeric_limits<int32_t>::min()),
                   buffer_));
  EXPECT_EQ(std::memcmp("\xff\xff\xff\xff\x0f", buffer_, 5), 0);

  ASSERT_EQ(5u,
            Encode(static_cast<int64_t>(std::numeric_limits<int32_t>::max()),
                   buffer_));
  EXPECT_EQ(std::memcmp("\xfe\xff\xff\xff\x0f", buffer_, 5), 0);

  ASSERT_EQ(10u, Encode(std::numeric_limits<int64_t>::min(), buffer_));
  EXPECT_EQ(
      std::memcmp("\xff\xff\xff\xff\xff\xff\xff\xff\xff\x01", buffer_, 10), 0);

  ASSERT_EQ(10u, Encode(std::numeric_limits<int64_t>::max(), buffer_));
  EXPECT_EQ(
      std::memcmp("\xfe\xff\xff\xff\xff\xff\xff\xff\xff\x01", buffer_, 10), 0);
}

TEST_F(Varint, EncodeDecodeSigned32) {
  // Set the increment to 1 to test every number (this is slow)
  static constexpr int kIncrement = 1'000'009;

  int32_t i = std::numeric_limits<int32_t>::min();
  while (true) {
    size_t encoded = Encode(i, buffer_);

    int64_t result;
    size_t decoded = Decode(buffer_, &result);

    EXPECT_EQ(encoded, decoded);
    ASSERT_EQ(i, result);

    if (i > std::numeric_limits<int32_t>::max() - kIncrement) {
      break;
    }

    i += kIncrement;
  }
}

TEST_F(Varint, EncodeDecodeUnsigned32) {
  // Set the increment to 1 to test every number (this is slow)
  static constexpr int kIncrement = 1'000'009;

  uint32_t i = 0;
  while (true) {
    size_t encoded = Encode(i, buffer_);

    uint64_t result;
    size_t decoded = Decode(buffer_, &result);

    EXPECT_EQ(encoded, decoded);
    ASSERT_EQ(i, result);

    if (i > std::numeric_limits<uint32_t>::max() - kIncrement) {
      break;
    }

    i += kIncrement;
  }
}

template <size_t kStringSize>
auto MakeBuffer(const char (&data)[kStringSize]) {
  constexpr size_t kSizeBytes = kStringSize - 1;
  static_assert(kSizeBytes <= 10, "Varint arrays never need be larger than 10");

  std::array<std::byte, kSizeBytes> array;
  std::memcpy(array.data(), data, kSizeBytes);
  return array;
}

TEST(VarintDecode, DecodeSigned64_SingleByte) {
  int64_t value = -1234;

  EXPECT_EQ(Decode(MakeBuffer("\x00"), &value), 1u);
  EXPECT_EQ(value, 0);

  EXPECT_EQ(Decode(MakeBuffer("\x01"), &value), 1u);
  EXPECT_EQ(value, -1);

  EXPECT_EQ(Decode(MakeBuffer("\x02"), &value), 1u);
  EXPECT_EQ(value, 1);

  EXPECT_EQ(Decode(MakeBuffer("\x03"), &value), 1u);
  EXPECT_EQ(value, -2);

  EXPECT_EQ(Decode(MakeBuffer("\x04"), &value), 1u);
  EXPECT_EQ(value, 2);

  EXPECT_EQ(Decode(MakeBuffer("\x04"), &value), 1u);
  EXPECT_EQ(value, 2);
}

TEST(VarintDecode, DecodeSigned64_MultiByte) {
  int64_t value = -1234;

  EXPECT_EQ(Decode(MakeBuffer("\x80\x01"), &value), 2u);
  EXPECT_EQ(value, 64);

  EXPECT_EQ(Decode(MakeBuffer("\x81\x01"), &value), 2u);
  EXPECT_EQ(value, -65);

  EXPECT_EQ(Decode(MakeBuffer("\x82\x01"), &value), 2u);
  EXPECT_EQ(value, 65);

  EXPECT_EQ(Decode(MakeBuffer("\xff\xff\xff\xff\x0f"), &value), 5u);
  EXPECT_EQ(value, std::numeric_limits<int32_t>::min());

  EXPECT_EQ(Decode(MakeBuffer("\xfe\xff\xff\xff\x0f"), &value), 5u);
  EXPECT_EQ(value, std::numeric_limits<int32_t>::max());

  EXPECT_EQ(
      Decode(MakeBuffer("\xff\xff\xff\xff\xff\xff\xff\xff\xff\x01"), &value),
      10u);
  EXPECT_EQ(value, std::numeric_limits<int64_t>::min());

  EXPECT_EQ(
      Decode(MakeBuffer("\xfe\xff\xff\xff\xff\xff\xff\xff\xff\x01"), &value),
      10u);
  EXPECT_EQ(value, std::numeric_limits<int64_t>::max());
}

TEST(Varint, ZigZagEncode_Int8) {
  EXPECT_EQ(ZigZagEncode(int8_t(0)), uint8_t(0));
  EXPECT_EQ(ZigZagEncode(int8_t(-1)), uint8_t(1));
  EXPECT_EQ(ZigZagEncode(int8_t(1)), uint8_t(2));
  EXPECT_EQ(ZigZagEncode(int8_t(-2)), uint8_t(3));
  EXPECT_EQ(ZigZagEncode(int8_t(2)), uint8_t(4));
  EXPECT_EQ(ZigZagEncode(int8_t(-33)), uint8_t(65));
  EXPECT_EQ(ZigZagEncode(int8_t(33)), uint8_t(66));
  EXPECT_EQ(ZigZagEncode(std::numeric_limits<int8_t>::min()),
            std::numeric_limits<uint8_t>::max());
  EXPECT_EQ(ZigZagEncode(std::numeric_limits<int8_t>::max()),
            std::numeric_limits<uint8_t>::max() - 1u);
}

TEST(Varint, ZigZagEncode_Int16) {
  EXPECT_EQ(ZigZagEncode(int16_t(0)), uint16_t(0));
  EXPECT_EQ(ZigZagEncode(int16_t(-1)), uint16_t(1));
  EXPECT_EQ(ZigZagEncode(int16_t(1)), uint16_t(2));
  EXPECT_EQ(ZigZagEncode(int16_t(-2)), uint16_t(3));
  EXPECT_EQ(ZigZagEncode(int16_t(2)), uint16_t(4));
  EXPECT_EQ(ZigZagEncode(int16_t(-3333)), uint16_t(6665));
  EXPECT_EQ(ZigZagEncode(int16_t(3333)), uint16_t(6666));
  EXPECT_EQ(ZigZagEncode(std::numeric_limits<int16_t>::min()),
            std::numeric_limits<uint16_t>::max());
  EXPECT_EQ(ZigZagEncode(std::numeric_limits<int16_t>::max()),
            std::numeric_limits<uint16_t>::max() - 1u);
}

TEST(Varint, ZigZagEncode_Int32) {
  EXPECT_EQ(ZigZagEncode(int32_t(0)), uint32_t(0));
  EXPECT_EQ(ZigZagEncode(int32_t(-1)), uint32_t(1));
  EXPECT_EQ(ZigZagEncode(int32_t(1)), uint32_t(2));
  EXPECT_EQ(ZigZagEncode(int32_t(-2)), uint32_t(3));
  EXPECT_EQ(ZigZagEncode(int32_t(2)), uint32_t(4));
  EXPECT_EQ(ZigZagEncode(int32_t(-128)), uint32_t(255));
  EXPECT_EQ(ZigZagEncode(int32_t(128)), uint32_t(256));
  EXPECT_EQ(ZigZagEncode(int32_t(-333333)), uint32_t(666665));
  EXPECT_EQ(ZigZagEncode(int32_t(333333)), uint32_t(666666));
  EXPECT_EQ(ZigZagEncode(std::numeric_limits<int32_t>::min()),
            std::numeric_limits<uint32_t>::max());
  EXPECT_EQ(ZigZagEncode(std::numeric_limits<int32_t>::max()),
            std::numeric_limits<uint32_t>::max() - 1u);
}

TEST(Varint, ZigZagEncode_Int64) {
  EXPECT_EQ(ZigZagEncode(int64_t(0)), uint64_t(0));
  EXPECT_EQ(ZigZagEncode(int64_t(-1)), uint64_t(1));
  EXPECT_EQ(ZigZagEncode(int64_t(1)), uint64_t(2));
  EXPECT_EQ(ZigZagEncode(int64_t(-2)), uint64_t(3));
  EXPECT_EQ(ZigZagEncode(int64_t(2)), uint64_t(4));
  EXPECT_EQ(ZigZagEncode(int64_t(-3333333333)), uint64_t(6666666665));
  EXPECT_EQ(ZigZagEncode(int64_t(3333333333)), uint64_t(6666666666));
  EXPECT_EQ(ZigZagEncode(std::numeric_limits<int64_t>::min()),
            std::numeric_limits<uint64_t>::max());
  EXPECT_EQ(ZigZagEncode(std::numeric_limits<int64_t>::max()),
            std::numeric_limits<uint64_t>::max() - 1u);
}

TEST(Varint, ZigZagDecode_Int8) {
  EXPECT_EQ(ZigZagDecode(uint8_t(0)), int8_t(0));
  EXPECT_EQ(ZigZagDecode(uint8_t(1)), int8_t(-1));
  EXPECT_EQ(ZigZagDecode(uint8_t(2)), int8_t(1));
  EXPECT_EQ(ZigZagDecode(uint8_t(3)), int8_t(-2));
  EXPECT_EQ(ZigZagDecode(uint8_t(4)), int8_t(2));
  EXPECT_EQ(ZigZagDecode(uint8_t(65)), int8_t(-33));
  EXPECT_EQ(ZigZagDecode(uint8_t(66)), int8_t(33));
  EXPECT_EQ(ZigZagDecode(std::numeric_limits<uint8_t>::max()),
            std::numeric_limits<int8_t>::min());
  EXPECT_EQ(ZigZagDecode(std::numeric_limits<uint8_t>::max() - 1u),
            std::numeric_limits<int8_t>::max());
}

TEST(Varint, ZigZagDecode_Int16) {
  EXPECT_EQ(ZigZagDecode(uint16_t(0)), int16_t(0));
  EXPECT_EQ(ZigZagDecode(uint16_t(1)), int16_t(-1));
  EXPECT_EQ(ZigZagDecode(uint16_t(2)), int16_t(1));
  EXPECT_EQ(ZigZagDecode(uint16_t(3)), int16_t(-2));
  EXPECT_EQ(ZigZagDecode(uint16_t(4)), int16_t(2));
  EXPECT_EQ(ZigZagDecode(uint16_t(6665)), int16_t(-3333));
  EXPECT_EQ(ZigZagDecode(uint16_t(6666)), int16_t(3333));
  EXPECT_EQ(ZigZagDecode(std::numeric_limits<uint16_t>::max()),
            std::numeric_limits<int16_t>::min());
  EXPECT_EQ(ZigZagDecode(std::numeric_limits<uint16_t>::max() - 1u),
            std::numeric_limits<int16_t>::max());
}

TEST(Varint, ZigZagDecode_Int32) {
  EXPECT_EQ(ZigZagDecode(uint32_t(0)), int32_t(0));
  EXPECT_EQ(ZigZagDecode(uint32_t(1)), int32_t(-1));
  EXPECT_EQ(ZigZagDecode(uint32_t(2)), int32_t(1));
  EXPECT_EQ(ZigZagDecode(uint32_t(3)), int32_t(-2));
  EXPECT_EQ(ZigZagDecode(uint32_t(4)), int32_t(2));
  EXPECT_EQ(ZigZagDecode(uint32_t(255)), int32_t(-128));
  EXPECT_EQ(ZigZagDecode(uint32_t(256)), int32_t(128));
  EXPECT_EQ(ZigZagDecode(uint32_t(666665)), int32_t(-333333));
  EXPECT_EQ(ZigZagDecode(uint32_t(666666)), int32_t(333333));
  EXPECT_EQ(ZigZagDecode(std::numeric_limits<uint32_t>::max()),
            std::numeric_limits<int32_t>::min());
  EXPECT_EQ(ZigZagDecode(std::numeric_limits<uint32_t>::max() - 1u),
            std::numeric_limits<int32_t>::max());
}

TEST(Varint, ZigZagDecode_Int64) {
  EXPECT_EQ(ZigZagDecode(uint64_t(0)), int64_t(0));
  EXPECT_EQ(ZigZagDecode(uint64_t(1)), int64_t(-1));
  EXPECT_EQ(ZigZagDecode(uint64_t(2)), int64_t(1));
  EXPECT_EQ(ZigZagDecode(uint64_t(3)), int64_t(-2));
  EXPECT_EQ(ZigZagDecode(uint64_t(4)), int64_t(2));
  EXPECT_EQ(ZigZagDecode(uint64_t(6666666665)), int64_t(-3333333333));
  EXPECT_EQ(ZigZagDecode(uint64_t(6666666666)), int64_t(3333333333));
  EXPECT_EQ(ZigZagDecode(std::numeric_limits<uint64_t>::max()),
            std::numeric_limits<int64_t>::min());
  EXPECT_EQ(ZigZagDecode(std::numeric_limits<uint64_t>::max() - 1llu),
            std::numeric_limits<int64_t>::max());
}

TEST(Varint, ZigZagEncodeDecode) {
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(0)), 0);
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(1)), 1);
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(-1)), -1);
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(8675309)), 8675309);
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(std::numeric_limits<int8_t>::min())),
            std::numeric_limits<int8_t>::min());
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(std::numeric_limits<int8_t>::max())),
            std::numeric_limits<int8_t>::max());
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(std::numeric_limits<int16_t>::min())),
            std::numeric_limits<int16_t>::min());
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(std::numeric_limits<int16_t>::max())),
            std::numeric_limits<int16_t>::max());
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(std::numeric_limits<int32_t>::min())),
            std::numeric_limits<int32_t>::min());
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(std::numeric_limits<int32_t>::max())),
            std::numeric_limits<int32_t>::max());
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(std::numeric_limits<int64_t>::min())),
            std::numeric_limits<int64_t>::min());
  EXPECT_EQ(ZigZagDecode(ZigZagEncode(std::numeric_limits<int64_t>::max())),
            std::numeric_limits<int64_t>::max());
}

}  // namespace
}  // namespace pw::varint