Demonstrating Comparison Usage with std::sort using Google Test

CMakeLists.txt

cmake_minimum_required(VERSION 3.25)
set(CMAKE_CXX_STANDARD 11)
project(c_cpp_snippet)

set(CMAKE_BUILD_TYPE Debug)
set(CMAKE_C_FLAGS_DEBUG "${CMAKE_C_FLAGS_DEBUG} -g")
set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -g")
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

# Find ccache
find_program(CCACHE_PROGRAM ccache)
if(CCACHE_PROGRAM)
    set_property(GLOBAL PROPERTY RULE_LAUNCH_COMPILE "${CCACHE_PROGRAM}")
    set_property(GLOBAL PROPERTY RULE_LAUNCH_LINK "${CCACHE_PROGRAM}")
endif()

## Configure testing
include(FetchContent)
set(FETCHCONTENT_QUIET TRUE)

# Download and configure googletest
FetchContent_Declare(
    gtest
    GIT_REPOSITORY https://github.com/google/googletest.git
    GIT_TAG v1.13.0
    GIT_SHALLOW ON
)
FetchContent_GetProperties(gtest)
if(NOT gtest_POPULATED)
  FetchContent_Populate(gtest)
  add_subdirectory(${gtest_SOURCE_DIR} ${CMAKE_BINARY_DIR}/_deps/gtest-build)
endif()

include_directories(${gtest_SOURCE_DIR}/googletest/include)

## Configure executables

add_executable(test main.cpp)

target_link_libraries(test PRIVATE gtest_main)

main.cpp

#include <gtest/gtest.h>

#include <algorithm>
#include <iostream>
#include <string>
#include <vector>
// ****************************************************************************
// This tests showcase the usage of comparisons with std::sort
// ****************************************************************************
typedef std::pair<std::string, int> Entry;

void print_table(const std::vector<Entry>& table, std::string legend) {
  std::cout << std::string(80, '=') << std::endl;

  std::cout << legend << std::endl;
  for (auto& host : table)
    std::cout << host.first << " " << host.second << std::endl;
  std::cout << std::string(80, '=') << std::endl;
}

void fill_table(std::vector<Entry>& table) {
  table.push_back(std::make_pair("sa.bbc.com", 2));
  table.push_back(std::make_pair("stats.g.doubleclick.net", 2));
  table.push_back(std::make_pair("sa.bbc.co.uk", 3));
  table.push_back(std::make_pair("px.dynamicyield.com", 2));
  table.push_back(std::make_pair("www.calcalist.co.il", 2));
  table.push_back(std::make_pair("www.ynet.co.il", 9));
  table.push_back(std::make_pair("edigitalsurvey.com", 1));
  table.push_back(std::make_pair("static.chartbeat.com", 2));
  table.push_back(std::make_pair("server.exposebox.com", 14));
  table.push_back(std::make_pair("node1.bbcimg.co.uk", 3));
  table.push_back(std::make_pair("news.bbcimg.co.uk", 2));
  table.push_back(std::make_pair("a.visualrevenue.com", 1));
  table.push_back(std::make_pair("r.bbci.co.uk", 1));
  table.push_back(std::make_pair("static.bbci.co.uk", 30));
  table.push_back(std::make_pair("b.scorecardresearch.com", 1));
  table.push_back(std::make_pair("clients1.google.com", 2));
  table.push_back(std::make_pair("open.live.bbc.co.uk", 1));
  table.push_back(std::make_pair("xnet.ynet.co.il", 2));
  table.push_back(std::make_pair("p.visualrevenue.com", 1));
  table.push_back(std::make_pair("emp.bbci.co.uk", 2));
  table.push_back(std::make_pair("sf.exposebox.com", 9));
  table.push_back(std::make_pair("dy.ynet.co.il", 1));
  table.push_back(std::make_pair("s2.googleusercontent.com", 8));
  table.push_back(std::make_pair("s3-eu-west-1.amazonaws.com", 1));
  table.push_back(std::make_pair("t1.visualrevenue.com", 1));
  table.push_back(std::make_pair("exposebox.blob.core.windows.net", 1));
  table.push_back(std::make_pair("bbc.com", 1));
  table.push_back(std::make_pair("go.ynet.co.il", 1));
  table.push_back(std::make_pair("ichef.bbci.co.uk", 29));
  table.push_back(std::make_pair("googleads.g.doubleclick.net", 1));
  table.push_back(std::make_pair("www.bbc.com", 1));
  table.push_back(std::make_pair("www.google-analytics.com", 1));
  table.push_back(std::make_pair("www.google.co.il", 2));
  table.push_back(std::make_pair("ocsp.startssl.com", 1));
  table.push_back(std::make_pair("www.bbc.co.uk", 2));
  table.push_back(std::make_pair("survey.112.2o7.net", 1));
  table.push_back(std::make_pair("www.google.com", 2));
  table.push_back(std::make_pair("st.dynamicyield.com", 1));
  table.push_back(std::make_pair("cdn.clicktale.net", 1));
  table.push_back(std::make_pair("ping.chartbeat.net", 2));
  table.push_back(std::make_pair("www.googleadservices.com", 1));
  table.push_back(std::make_pair("static.bbc.co.uk", 1));
}

TEST(std_sort, my_change) {
  std::vector<Entry> table;
  fill_table(table);

  print_table(table, "==== Before sort");

  auto hostnameComparer = [](const Entry& leftHost, const Entry& rightHost) {
    return leftHost.second > rightHost.second ||
           (leftHost.second == rightHost.second &&
            leftHost.first > rightHost.first);
  };

  std::sort(table.begin(), table.end(), hostnameComparer);
  print_table(table, "==== My change after sort...");

  SUCCEED();
}

TEST(std_sort, his_change) {
  std::vector<Entry> table;
  fill_table(table);

  print_table(table, "==== Before sort");

  auto hostnameComparer = [](const Entry& leftHost, const Entry& rightHost) {
    return leftHost.second < rightHost.second ||
           (leftHost.second == rightHost.second &&
            leftHost.first < rightHost.first);
  };

  std::sort(table.begin(), table.end(), hostnameComparer);
  print_table(table, "==== His change after sort...");

  SUCCEED();
}

int main(int argc, char** argv) {
  ::testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}

original_table.txt

----------------------------------------------------
| Hostname                                 | Count |
----------------------------------------------------
| static.bbci.co.uk                        | 30    |
| ichef.bbci.co.uk                         | 29    |
| server.exposebox.com                     | 14    |
| www.ynet.co.il                           | 9     |
| sf.exposebox.com                         | 9     |
| s2.googleusercontent.com                 | 8     |
| sa.bbc.co.uk                             | 3     |
| node1.bbcimg.co.uk                       | 3     |
| xnet.ynet.co.il                          | 2     |
| www.google.com                           | 2     |
| www.google.co.il                         | 2     |
| www.calcalist.co.il                      | 2     |
| www.bbc.co.uk                            | 2     |
| stats.g.doubleclick.net                  | 2     |
| static.chartbeat.com                     | 2     |
| sa.bbc.com                               | 2     |
| px.dynamicyield.com                      | 2     |
| ping.chartbeat.net                       | 2     |
| news.bbcimg.co.uk                        | 2     |
| emp.bbci.co.uk                           | 2     |
| clients1.google.com                      | 2     |
| www.googleadservices.com                 | 1     |
| www.google-analytics.com                 | 1     |
| www.bbc.com                              | 1     |
| t1.visualrevenue.com                     | 1     |
| survey.112.2o7.net                       | 1     |
| static.bbc.co.uk                         | 1     |
| st.dynamicyield.com                      | 1     |
| s3-eu-west-1.amazonaws.com               | 1     |
| r.bbci.co.uk                             | 1     |
| p.visualrevenue.com                      | 1     |
| open.live.bbc.co.uk                      | 1     |
| ocsp.startssl.com                        | 1     |
| googleads.g.doubleclick.net              | 1     |
| go.ynet.co.il                            | 1     |
| exposebox.blob.core.windows.net          | 1     |
| edigitalsurvey.com                       | 1     |
| dy.ynet.co.il                            | 1     |
| cdn.clicktale.net                        | 1     |
| bbc.com                                  | 1     |
| b.scorecardresearch.com                  | 1     |
| a.visualrevenue.com                      | 1     |
----------------------------------------------------