folly/folly/lang/test/CStringTest.cpp

/*
 * Copyright (c) Meta Platforms, Inc. and affiliates.
 *
 * 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 <folly/lang/CString.h>

#include <folly/portability/GTest.h>

class CStringTest : public testing::Test {};

TEST_F(CStringTest, memrchr) {
  const char* const cdata = "foobar";
  char mdata[] = "foobar";

  EXPECT_EQ(cdata + 3, folly::memrchr(cdata, 'b', 6));
  EXPECT_EQ(mdata + 3, folly::memrchr(mdata, 'b', 6));

  EXPECT_EQ(nullptr, folly::memrchr(cdata, 'x', 6));
  EXPECT_EQ(nullptr, folly::memrchr(mdata, 'x', 6));

  EXPECT_EQ(cdata + 3, folly::detail::memrchr_fallback(cdata, 'b', 6));
  EXPECT_EQ(mdata + 3, folly::detail::memrchr_fallback(mdata, 'b', 6));

  EXPECT_EQ(nullptr, folly::detail::memrchr_fallback(cdata, 'x', 6));
  EXPECT_EQ(nullptr, folly::detail::memrchr_fallback(mdata, 'x', 6));
}

TEST_F(CStringTest, strlcpy) {
  char buf[6];

  EXPECT_EQ(3, folly::strlcpy(buf, "abc", 6));
  EXPECT_EQ('\0', buf[3]);
  EXPECT_EQ("abc", std::string(buf));

  EXPECT_EQ(7, folly::strlcpy(buf, "abcdefg", 3));
  EXPECT_EQ('\0', buf[2]);
  EXPECT_EQ("ab", std::string(buf));

  const char* big_string = "abcdefghijklmnop";

  EXPECT_EQ(strlen(big_string), folly::strlcpy(buf, big_string, sizeof(buf)));
  EXPECT_EQ('\0', buf[5]);
  EXPECT_EQ("abcde", std::string(buf));

  buf[0] = 'z';
  EXPECT_EQ(strlen(big_string), folly::strlcpy(buf, big_string, 0));
  EXPECT_EQ('z', buf[0]); // unchanged, size = 0
}