utils/byte_readers_test.cc

// Copyright 2026 Google LLC
//
// 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 "utils/byte_readers.h"

#include <cstdint>

#include "absl/status/status.h"
#include "absl/status/status_matchers.h"
#include "absl/strings/string_view.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

namespace credentio {

namespace {

using ::absl_testing::IsOk;
using ::absl_testing::IsOkAndHolds;
using ::absl_testing::StatusIs;

TEST(ByteReadersTest, ReadTooSmall) {
  EXPECT_THAT(ReadUint<uint16_t>("\x12"),
              StatusIs(absl::StatusCode::kInvalidArgument));
}

TEST(ByteReadersTest, ReadUint) {
  EXPECT_THAT(ReadUint<uint16_t>("\x12\x34"), IsOkAndHolds(0x1234));
}

TEST(ByteReadersTest, ReadUintWithRemainder) {
  EXPECT_THAT(ReadUint<uint16_t>("\x12\x34\x56\x78"), IsOkAndHolds(0x1234));
}

TEST(ByteReadersTest, ConsumeNull) {
  EXPECT_THAT(ConsumeUint<uint16_t>(nullptr),
              StatusIs(absl::StatusCode::kInvalidArgument));
}

TEST(ByteReadersTest, ConsumeTooSmall) {
  absl::string_view input = "\x12";
  EXPECT_THAT(ConsumeUint<uint16_t>(&input),
              StatusIs(absl::StatusCode::kInvalidArgument));
  EXPECT_EQ(input, "\x12");
}

TEST(ByteReadersTest, ConsumeUint) {
  absl::string_view input = "\x12\x34";
  EXPECT_THAT(ConsumeUint<uint16_t>(&input), IsOkAndHolds(0x1234));
  EXPECT_EQ(input, "");
}

TEST(ByteReadersTest, ConsumeUintWithRemainder) {
  absl::string_view input = "\x12\x34\x56\x78";
  EXPECT_THAT(ConsumeUint<uint16_t>(&input), IsOkAndHolds(0x1234));
  EXPECT_EQ(input, "\x56\x78");
}

TEST(ByteReadersTest, SkipBytesNull) {
  EXPECT_THAT(SkipBytes<uint16_t>(nullptr),
              StatusIs(absl::StatusCode::kInvalidArgument));
}

TEST(ByteReadersTest, SkipBytes) {
  absl::string_view input = "\x12\x34";
  EXPECT_THAT(SkipBytes<uint8_t>(&input), IsOk());
  EXPECT_EQ(input, "\x34");
}

TEST(ByteReadersTest, SkipBytesAll) {
  absl::string_view input = "\x12\x34";
  EXPECT_THAT(SkipBytes<uint16_t>(&input), IsOk());
  EXPECT_EQ(input, "");
}

TEST(ByteReadersTest, SkipBytesNotEnough) {
  absl::string_view input = "\x12\x34";
  EXPECT_THAT(SkipBytes<uint32_t>(&input),
              StatusIs(absl::StatusCode::kInvalidArgument));
  EXPECT_EQ(input, "\x12\x34");
}

}  // namespace
}  // namespace credentio