file_atomic_replace_test.cc

// Copyright 2019 The Cobalt Authors. All Rights Reserved.
//
// 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
//
//     http://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 <fcntl.h>
#include <sys/stat.h>

#include "starboard/common/file.h"
#include "starboard/file.h"
#include "starboard/nplb/file_helpers.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace starboard {
namespace nplb {
namespace {

static const char kTestContents[] =
    "The quick brown fox jumps over the lazy dog.";
static const int kTestContentsLength = sizeof(kTestContents);

bool CompareFileContentsToString(const char* filename,
                                 const char* str,
                                 int size) {
  char result[kTestContentsLength] = {'\0'};

  int file = open(filename, O_RDONLY, S_IRUSR | S_IWUSR);

  EXPECT_TRUE(starboard::IsValid(file));

  // We always try to read kTestContentsLength since the data will at most be
  // this long. There are test cases where the number of bytes read will be
  // less.
  EXPECT_EQ(size, starboard::ReadAll(file, result, kTestContentsLength));
  EXPECT_TRUE(!close(file));

  return strncmp(str, result, kTestContentsLength) == 0;
}

bool FileExists(const char* path) {
  struct stat info;
  return stat(path, &info) == 0;
}

TEST(SbFileAtomicReplaceTest, ReplacesValidFile) {
  ScopedRandomFile random_file(ScopedRandomFile::kDefaultLength,
                               ScopedRandomFile::kCreate);
  const std::string& filename = random_file.filename();

  EXPECT_TRUE(FileExists(filename.c_str()));
  EXPECT_TRUE(SbFileAtomicReplace(filename.c_str(), kTestContents,
                                  kTestContentsLength));
  EXPECT_TRUE(CompareFileContentsToString(filename.c_str(), kTestContents,
                                          kTestContentsLength));
}

TEST(SbFileAtomicReplaceTest, ReplacesNonExistentFile) {
  ScopedRandomFile random_file(ScopedRandomFile::kDontCreate);
  const std::string& filename = random_file.filename();

  EXPECT_FALSE(FileExists(filename.c_str()));
  EXPECT_TRUE(SbFileAtomicReplace(filename.c_str(), kTestContents,
                                  kTestContentsLength));
  EXPECT_TRUE(CompareFileContentsToString(filename.c_str(), kTestContents,
                                          kTestContentsLength));
}

TEST(SbFileAtomicReplaceTest, ReplacesWithNoData) {
  ScopedRandomFile random_file(ScopedRandomFile::kCreate);
  const std::string& filename = random_file.filename();

  EXPECT_TRUE(FileExists(filename.c_str()));
  EXPECT_TRUE(SbFileAtomicReplace(filename.c_str(), nullptr, 0));
  EXPECT_TRUE(CompareFileContentsToString(filename.c_str(), "\0", 0));
}

TEST(SbFileAtomicReplaceTest, FailsWithNoDataButLength) {
  ScopedRandomFile random_file(ScopedRandomFile::kCreate);
  const std::string& filename = random_file.filename();

  EXPECT_TRUE(FileExists(filename.c_str()));
  EXPECT_FALSE(SbFileAtomicReplace(filename.c_str(), nullptr, 1));
}

TEST(SbFileAtomicReplaceTest, FailsWithInvalidLength) {
  ScopedRandomFile random_file(ScopedRandomFile::kCreate);
  const std::string& filename = random_file.filename();

  EXPECT_TRUE(FileExists(filename.c_str()));
  EXPECT_FALSE(SbFileAtomicReplace(filename.c_str(), kTestContents, -1));
}

}  // namespace
}  // namespace nplb
}  // namespace starboard