Unit testing involves testing individual units or components of an application to ensure they operate as expected. The UnitTest++ and HippoMocks frameworks allow writing and running unit tests in C++. UnitTest++ provides macros and functions to define tests and make assertions while HippoMocks allows mocking dependencies to isolate units during testing.

1. Introduction to
Unit Testing
Author : Pooya Sagharchi Ha
January 27, 2015

2. Agenda
● What is Unit Testing ?
● Why should we Unit Test?
● Isolate units for testing
● UnitTest++ framework
● HippoMocks framework

3. Unit Testing
● The smallest testable parts of an application, are called
units
● Unit Test is a method in which a programmer tests
individual units
● execute a program using artificial data

4. Unit Testing
input
Main Class Testing Class
output
True or False

5. Isolate Unit Testing
● it goal is to isolate each part of the program and show that the individual parts
are correct
Class 1
Class 2
Class 3
Class 4
Class 3
Testing Class
input
output
True or

6. Why Unit Testing?
● helps to find the problems early in the software
development
● Can be used to validate that the code functionality still
works after code change

7. UnitTest++
● lightweight
● Simplicity
● Portability ( platform Linux, Mac and windows )
● Speed

8. Getting started:
1. Create a header file on UnitTests folder
2. Include UnitTest++.h and TestReporterStdout.h
3. Write your test in TEST body
4. Compile it
UnitTest++

9. UnitTest++
For example :
#include "UnitTest++.h"
#include "TestReportsStdout.h"
TEST(ChechSumTest)
{
int sum =0;
for(int i=0; i < 5; ++i)
sum += i;
CHECK_EQUAL(10, sum);
}

10. UnitTest++
● Test macro
Define : simply put the following code in a .cpp file of your choice.
Syntax :
TEST(YourTestName)
{
}

11. UnitTest++
● Suit macro
Define : A suite serves as a namespace for test names, so that the same test name can be used in two
different contexts.
Syntax :
SU ITE(YourSuiteName)
{
TEST(YourTestName)
{
}
TEST(YourOtherTestName)
{
}
}

12. UnitTest++
● Check macro
Define : It will fail if the boolean expression evaluates to false and conversely.
Syntax :
TEST(YourTestName)
{
Check(value);
}

13. UnitTest++
● Check Equal macro
Define : It will compare expected argument and actual argument.
Syntax :
TEST(YourTestName)
{
Check_EQUAL(expected, actual);
}

14. UnitTest++
● Check Close macro
Define : It is used for floating-point comparison.
Syntax :
TEST(YourTestName)
{
Check_CLOSE(expected, actual, tolerance);
}

15. UnitTest++
● Array macro
There is a set of check macros for array comparison as well.
Syntax :
TEST(YourTestName)
{
Check_Array_EQUAL(expected, actual, count);
Check_Array_CLOSE(expected, actual, tolerance);
Check_Array2D_EQUAL(expected, actual, row, columns, tolerance);
}

16. UnitTest++
● Exception check macros
Define : which asserts that its enclosed expression throws the specified type.
Syntax :
TEST(YourTestName)
{
Check_THROW(expression, ExpectedExpectionType);
}

17. HippoMocks
Getting started:
1. Create a header file on UnitTests folder
2. Include UnitTest++.h and TestReporterStdout.h and
hippmocks.h
3. Write your test in TEST body
4. Compile it

18. HippoMocks
● MockRepository class
Define : Create a MockRepository on the stack.
Syntax :
TEST(YourTestName)
{
MockRepository mocks;
}

19. HippoMocks
● Interface Mock
Define : Used to create an instance of a class that implements a given interface.
Syntax :
TEST(YourTestName)
{
MockRepository mocks;
ClassName *classnameMock = mocks.Mock<ClassName>();
}

20. HippoMocks
● Expected Call
Define : Indicates that the given method on the mock will be called. If the method is not called
before the Repository destructs, a runtime error is generated.
Syntax :
TEST(YourTestName)
{
MockRepository mocks;
ClassName *classnameMock = mocks.Mock<ClassName>();
mock.ExpectCall(obj, func);
}

21. HippoMocks
● Expected Call
Define : AutoExpect can be called prior to calls to ExpectCall but the order of your program
increase.
Syntax :
TEST(YourTestName)
{
MockRepository mocks;
ClassName *classnameMock = mocks.Mock<ClassName>();
mocks.autoExpect = false or true;
}

22. HippoMocks
● On Call
Define : Similar to ExpectCall, except that it's okay if the method doesn't get called.
Syntax :
TEST(YourTestName)
{
MockRepository mocks;
ClassName *classnameMock = mocks.Mock<ClassName>();
mock.OnCall(obj, func);
}

23. HippoMocks
● Never Call
Define : Similar to ExpectCall, except that it sets up expectation that the
method will never be called.
Syntax :
TEST(YourTestName)
{
MockRepository mocks;
ClassName *classnameMock = mocks.Mock<ClassName>();
mock.NeverCall(obj, func);
}

24. HippoMocks
● TCall class
Define : This class is not instantiated directly. It's returned by
MockRepository::ExpectCall The TCall class can be used to further refine the
expectations of the method call.

25. HippoMocks
● With
Define : When used, indicates what parameters expected to be passed in.
Syntax :
TEST(YourTestName)
{
MockRepository mocks;
ClassName *classnameMock = mocks.Mock<ClassName>();
mock.ExpectCall(obj, func).With(value);
}

26. HippoMocks
● Return
Define : When used, indicates what value the method will return.
Syntax :
TEST(YourTestName)
{
MockRepository mocks;
ClassName *classnameMock = mocks.Mock<ClassName>();
mock.ExpectCall(obj, func).Return(obj);
}

27. HippoMocks
● Throw
Define : When used, indicates that the method must throw an exception.
Syntax :
TEST(YourTestName)
{
MockRepository mocks;
ClassName *classnameMock = mocks.Mock<ClassName>();
mock.ExpectCall(obj, func).Throw(exception);
}

28. HippoMocks
● Do
Define : When used, indicates what the method will do by passing in a function pointer.
Syntax :
TEST(YourTestName)
{
MockRepository mocks;
ClassName *classnameMock = mocks.Mock<ClassName>();
mock.ExpectCall(obj, func).Do(function);
}