Introduction
Google Test is one of the available Frameworks to create unit test for C++. In this example I will use CMake to configure the project and build. Furthermore, for the dependency manager I will use the new and shiny conan.Before starting, why use a dependency manager such as conan or software to configure and build such as CMake? Because these technologies are widely use it in real projects.
All the code and configuration files used for this entry are available in this repo in GitHub.
Step 1 Install conan, configure project and gather dependencies
First of all we need to have install conan from pip2 doing:pip2 install conanNext step will be preparing the conanfile.txt to gather de dependencies:
[requires]
gtest/1.7.0@lasote/stable
[options]
gtest:shared=True
[generators]
cmakeconan install .WARN: Migration: Updating settings.yml with new gcc versions
Requirements
gtest/1.7.0@lasote/stable
Package for gtest/1.7.0@lasote/stable in /home/maitesin/.conan/data/gtest/1.7.0/lasote/stable/package/ca89189bc59ff53842d6beea76549f289b7b88bd
Generated conaninfo.txt
Generated conanbuildinfo.cmakeStep 2 configuring CMake
The configuration will be done in the CMakeLists.txt file:project(Google_test_example)
cmake_minimum_required(VERSION 2.8)
include(conanbuildinfo.cmake)
CONAN_BASIC_SETUP()
INCLUDE_DIRECTORIES(src)
ADD_EXECUTABLE(run_test src/test.cpp)
TARGET_LINK_LIBRARIES(run_test ${CONAN_LIBS})Step 3 code and unit test
The code will be held in the src folder. It will contain two files: functions.h and test.cpp.The function(s) we want to test will be in the header file function.h:
int int_addition(int a, int b) {
int c = a + b;
return c;
}#include "gtest/gtest.h"
#include "functions.h"
TEST(IntAddition, Negative) {
EXPECT_EQ(-5, int_addition(-2, -3)) << "This will be shown in case it fails";
EXPECT_EQ(-3, int_addition(5, -8));
}
TEST(IntAddition, Positive) {
EXPECT_EQ(4, int_addition(1, 3));
EXPECT_EQ(9, int_addition(4, 5));
}
int main(int argc, char **argv) {
testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}Step 4 putting all together
What is left to do is actually build the project and run the test. In order to do this we need to run:cmake .-- The C compiler identification is GNU 5.3.0
-- The CXX compiler identification is GNU 5.3.0
-- Check for working C compiler: /usr/bin/cc
-- Check for working C compiler: /usr/bin/cc -- works
-- Detecting C compiler ABI info
-- Detecting C compiler ABI info - done
-- Detecting C compile features
-- Detecting C compile features - done
-- Check for working CXX compiler: /usr/bin/c++
-- Check for working CXX compiler: /usr/bin/c++ -- works
-- Detecting CXX compiler ABI info
-- Detecting CXX compiler ABI info - done
-- Detecting CXX compile features
-- Detecting CXX compile features - done
-- Configuring done
-- Generating done
-- Build files have been written to: /home/maitesin/workspace/blog/google_test_2015_12_22makeScanning dependencies of target run_test
[ 50%] Building CXX object CMakeFiles/run_test.dir/src/test.cpp.o
[100%] Linking CXX executable bin/run_test
[100%] Built target run_test./bin/run_test[==========] Running 2 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 2 tests from IntAddition
[ RUN ] IntAddition.Negative
[ OK ] IntAddition.Negative (0 ms)
[ RUN ] IntAddition.Positive
[ OK ] IntAddition.Positive (0 ms)
[----------] 2 tests from IntAddition (0 ms total)
[----------] Global test environment tear-down
[==========] 2 tests from 1 test case ran. (0 ms total)
[ PASSED ] 2 tests.
