Google Test is a unit testing library for the C++ programming language, based on the xUnit architecture. The library is released under the BSD 3-clause license.
Why Google Test Framework ?
Google test framework is better than other frameworks such as CppUnit, CppTest,Cunit etc.
Because of the following reasons
- You can repeat the same test a thousand times using the Google framework
- If you pass --gtest_repeat=2 --gtest_break_on_failure on the command line, the same test
- is repeated twice. If the test fails, the debugger is automatically invoked.
- You can perform death Tests (ASSERT )
- Temporarily disabling tests
- setup and teardown fixtures etc..
How to install Google test Framework?
Step 1:
apt-get install libgtest-dev
# It is required to compile the gtest library before you start the application.
Step 2: Go to your home directory
cd ~
Step 3: Compile the Google Test library (gtest)
g++ -I /usr/include/gtest -I /usr/src/gtest/ -c /usr/src/gtest/src/gtest-all.cc
Step 4: Build the (libgtest.a) static library from gtest-all.o objects (gtest)
ar -rv libgtest.a gtest-all.o
Step 5: Move the (libgtest.a) static library to /usr/lib directory, so that GCC linker can find the library.
mv libgtest.a /usr/lib/
----------------------------------------------------------------------
Sample Example to test the Employee details functionality
----------------------------------------------------------------------
-------------------------------
vim Employee_details.h
-------------------------------
#ifndef EMPLOYEE_DETAILS_H
#define EMPLOYEE_DETAILS_H
#include "string"
using std::string;
class Employee
{
string employee_name;
int employee_id;
int salary;
public:
Employee();
// Set functions
void setEmployeeName(string name);
void setEmployeeId(int employee_id);
void setEmployeeSalary(int salary);
// Get functions
string getEmployeeName();
int getEmployeeId();
int getEmployeeSalary();
};
#endif /* EMPLOYEE_DETAILS_H */
---------------------------------
vim Employee_details.cpp
---------------------------------
/***************************
* Employee Details
*
***************************/
#include "Employee_details.h"
// Default constructor
Employee :: Employee()
{
}
// set the Employee Name
void Employee :: setEmployeeName(string name)
{
this->employee_name = name;
}
// set the Employee Id
void Employee :: setEmployeeId(int id)
{
this->employee_id = id;
}
// set the Employee Salary
void Employee :: setEmployeeSalary(int sal)
{
this->salary = sal;
}
// get the Employee Name
string Employee :: getEmployeeName()
{
return this->employee_name;
}
// get the Employee Id
int Employee :: getEmployeeId()
{
return this->employee_id;
}
// get the Employee Salary
int Employee :: getEmployeeSalary()
{
return this->salary;
}
------------------------------------
vim google_test_example.cpp
-----------------------------------
#include "gtest/gtest.h"
#include "string"
// Add the Employee details header file
#include "Employee_details.h"
// Test Case #1
TEST(Employee, testEmployeeName)
{
string testName="muni";
// Create emp object
Employee *emp = new Employee();
// Set the name
if(emp)
emp->setEmployeeName(testName);
// Validate the Name
EXPECT_EQ(emp->getEmployeeName(), testName);
delete emp;
}
// Test Case #2
TEST(Employee, testEmployeeId)
{
int id=3;
// Create emp object
Employee *emp = new Employee();
// Set the name
if(emp)
emp->setEmployeeId(id);
// Validate the Name
EXPECT_EQ(emp->getEmployeeId(), id);
delete emp;
}
// Test Case #3
TEST(Employee, testEmployeeSalary)
{
int sal=100;
// Create emp object
Employee *emp = new Employee();
// Set the name
if(emp)
emp->setEmployeeSalary(sal);
// Validate the Salary
EXPECT_EQ(emp->getEmployeeSalary(), sal);
delete emp;
}
// Main Function
int main(int argc, char* *argv) {
testing::InitGoogleTest(&argc, argv);
return RUN_ALL_TESTS();
}
---------------
vi Makefile
--------------
all:
g++ -c ./*.cpp
g++ ./google_test_example.cpp Employee_details.o /usr/lib/libgtest.a -o google_test_example.bin -fPIC -O2 -g -Wall -lpthread
clean:
rm *.o
rm ./google_test_example.bin
Output of make file:
root@muni-VirtualBox:/home/muni/google_test# ls
Employee_details.cpp Employee_details.h Employee_details.o google_test_example.bin google_test_example.cpp google_test_example.o Makefile
-----------------------------------
How to run the google test?
-----------------------------------
root@muni-VirtualBox:/home/muni/google_test# ./google_test_example.bin
[==========] Running 3 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 3 tests from Employee
[ RUN ] Employee.testEmployeeName
[ OK ] Employee.testEmployeeName (1 ms)
[ RUN ] Employee.testEmployeeId
[ OK ] Employee.testEmployeeId (0 ms)
[ RUN ] Employee.testEmployeeSalary
[ OK ] Employee.testEmployeeSalary (0 ms)
[----------] 3 tests from Employee (1 ms total)
[----------] Global test environment tear-down
[==========] 3 tests from 1 test case ran. (1 ms total)
[ PASSED ] 3 tests.
# Run the above test case twice
root@muni-VirtualBox:/home/muni/google_test# ./google_test_example.bin --gtest_repeat=2 --gtest_break_on_failure
Repeating all tests (iteration 1) . . .
[==========] Running 3 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 3 tests from Employee
[ RUN ] Employee.testEmployeeName
[ OK ] Employee.testEmployeeName (0 ms)
[ RUN ] Employee.testEmployeeId
[ OK ] Employee.testEmployeeId (0 ms)
[ RUN ] Employee.testEmployeeSalary
[ OK ] Employee.testEmployeeSalary (0 ms)
[----------] 3 tests from Employee (1 ms total)
[----------] Global test environment tear-down
[==========] 3 tests from 1 test case ran. (3 ms total)
[ PASSED ] 3 tests.
Repeating all tests (iteration 2) . . .
[==========] Running 3 tests from 1 test case.
[----------] Global test environment set-up.
[----------] 3 tests from Employee
[ RUN ] Employee.testEmployeeName
[ OK ] Employee.testEmployeeName (0 ms)
[ RUN ] Employee.testEmployeeId
[ OK ] Employee.testEmployeeId (0 ms)
[ RUN ] Employee.testEmployeeSalary
[ OK ] Employee.testEmployeeSalary (0 ms)
[----------] 3 tests from Employee (1 ms total)
[----------] Global test environment tear-down
[==========] 3 tests from 1 test case ran. (3 ms total)
[ PASSED ] 3 tests.
