// Copyright 2025 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/base/net_platform_api_util.h"

#include <string_view>

#include "base/check_op.h"
#include "base/containers/span.h"
#include "base/strings/string_view_util.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace net {

TEST(NetPlatformApiUtilTest, CopyStringAndNulToSpan) {
  constexpr std::string_view kTestCases[] = {
      "",
      "1",
      "1234",
  };

  for (const auto& test_case : kTestCases) {
    char dest[5] = {'a', 'a', 'a', 'a', 'a'};
    CopyStringAndNulToSpan(test_case, dest);

    // A string_view that includes all of `dest`, including the terminating nul
    // and any characters after that.
    auto dest_string = base::as_string_view(base::span(dest));

    EXPECT_EQ(dest_string.substr(0u, test_case.size()), test_case);
    EXPECT_EQ(dest_string[test_case.size()], '\0');
    for (auto unmodified_char : dest_string.substr(test_case.size() + 1)) {
      EXPECT_EQ(unmodified_char, 'a');
    }
  }
}

TEST(NetPlatformApiUtilTest, SpanWithNulToStringView) {
  // Test span representation of an empty string, with and without a terminating
  // null.
  const char kTest1[] = "";
  EXPECT_EQ(kTest1, SpanMaybeWithNulToStringView(
                        base::span_with_nul_from_cstring(kTest1)));
  EXPECT_EQ(kTest1,
            SpanMaybeWithNulToStringView(base::span_from_cstring(kTest1)));

  // Test span representation of a string, with and without a terminating null.
  const char kTest2[] = "1234";
  EXPECT_EQ(kTest2, SpanMaybeWithNulToStringView(
                        base::span_with_nul_from_cstring(kTest2)));
  EXPECT_EQ(kTest2,
            SpanMaybeWithNulToStringView(base::span_from_cstring(kTest2)));

  const char kTest3[] = "1234\0";
  // Document what we expect from `span_with_nul_from_cstring` here.
  CHECK_EQ(sizeof(kTest3), base::span_with_nul_from_cstring(kTest3).size());
  EXPECT_EQ("1234", SpanMaybeWithNulToStringView(
                        base::span_with_nul_from_cstring(kTest3)));

  const char kTest4[] =
      "1234"
      "\0"
      "5678";
  EXPECT_EQ("1234", SpanMaybeWithNulToStringView(
                        base::span_with_nul_from_cstring(kTest4)));

  const char kTest5[] =
      "1234"
      "\0"
      "5"
      "\0\0"
      "678";
  EXPECT_EQ("1234", SpanMaybeWithNulToStringView(
                        base::span_with_nul_from_cstring(kTest5)));
}

}  // namespace net