Introduction

GoogleTest is a framework based on the xUnit architecture. This framework is to write test for C++ code and valid for the most common platforms.

Installation

To build and install the google test library, first, we must install python and cmake in our development environment. These are straight forward installations using DMG’s.

Download CMake
Download Python version 2.7

Now we can move onto installing GTest. Download GTest 1.7.0 from the Google GTest repository. Once downloaded configure GTest using.

Download and Extract using: 
% gtest_version=1.7.0
% wget https://googletest.googlecode.com/files/gtest-$gtest_version.zip --no-check-certificate
% unzip gtest-$gtest_version.zip

For build the library type:
% cd gtest-$gtest_version
% mkdir mybuild
% cd mybuild
% cmake -G"Unix Makefiles" ..
% make

Install the compiled library:
% cp -r ../include/gtest /usr/local/include
% cp lib*.a /usr/local/lib

Verify Functionality

We’ll write up a simple function sum and test the different asserts GTest provides us. The basic functions of GTest can be found in the table:

Fatal assertion	Nonfatal assertion	Verifies
ASSERT_EQ(expected, actual);	EXPECT_EQ(expected, actual);	expected == actual
ASSERT_NE(val1, val2);	EXPECT_NE(val1, val2);	val1 != val2
ASSERT_LT(val1, val2);	EXPECT_LT(val1, val2);	val1 < val2
ASSERT_LE(val1, val2);	EXPECT_LE(val1, val2);	val1 <= val2
ASSERT_GT(val1, val2);	EXPECT_GT(val1, val2);	val1 > val2
ASSERT_GE(val1, val2);	EXPECT_GE(val1, val2);	val1 >= val2
		Source GTest Primer

Write up a test file called test.cpp

#include <cassert>  // assert
#include <iostream> // cout, endl

#include <gtest/gtest.h>

int sum(int a, int b){
  return a+b;
}

TEST(MyUnitTests, test_1) {
    ASSERT_EQ(sum(1,1), 2);}

TEST(MyUnitTests, test_2) {
    ASSERT_EQ(sum(2,2), 4);}

TEST(MyUnitTests, test_3) {
    ASSERT_EQ(sum(10,-1), 9);}



GTEST_API_ int main(int argc, char **argv) {
  std::cout << "Running main() from testmain.cc\n";
 
  testing::InitGoogleTest(&argc, argv);
  return RUN_ALL_TESTS();
}

% g++ -pedantic -std=c++11 -Wall test.cpp -o UnitTest -lgtest -lgtest_main
Running main() from testmain.cc
[==========] Running 3 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 3 tests from MyUnitTests
[ RUN      ] MyUnitTests.test_1
[       OK ] MyUnitTests.test_1 (0 ms)
[ RUN      ] MyUnitTests.test_2
[       OK ] MyUnitTests.test_2 (0 ms)
[ RUN      ] MyUnitTests.test_3
[       OK ] MyUnitTests.test_3 (0 ms)
[----------] 3 tests from MyUnitTests (0 ms total)

[----------] Global test environment tear-down
[==========] 3 tests from 1 test case ran. (0 ms total)
[  PASSED  ] 3 tests.