introduction to test driven development and mocking

1. Introduction to
Test Driven Development
And
Mocking
@saeed_shargi

2. The Problem

3. Time taken to fix bugs
1000
750
500
250
0
Design Implementation QA Post-Release

4. Solution
 Testing
 Test Driven Development

5. Testing
Design Implementation Test

6. TDD
Design Test Implementation

7. TDD
Design Test Implementation Test

8. TDD
Design
Test Test
Implementation

9. TDD
Design
Test Test
Implementation

10. What is TDD?
 Write a test before writing a code.
 Specification not validation
 Think through requirements or design
before write code.
 Programming technique
 Ron Jefferies -> write clean code

11. What is TDD?

12. What is TDD?

13. What is TDD?
TDD = Refactoring + TFD

14. Two Level of TDD
1) Acceptance TDD (ATDD)
2) Developer TDD

15. ATDD and TDD Together

16. Development Style
1) KISS
Writing only the code
necessary to pass test
2) YAGNI

17. Benefits
1) Suit unit test provides that components
working.
2) Clear code
3) Forces critical analysis and design
4) Better design , loosely coupled , easily
maintainable
5) Reduced debugging time

18. Tools
 Cpputest
 csUnit (.Net)
 Cunit
 Dunit (Delphi)
 DBUnit
 JUnit
 NUnit
 PHPUnit
 xUnit.net

19. Mocking
 Simple classes dose not have
dependencies.
 In Action classes maybe have external
dependencies like connect to database
, connect to web services.
 Good Test should be isolated.
 Integration test.
 Test should be fast.

20. Mocking
 Two way to isolated :
1) Use Interface
2) Mocking framework

21. Example of using Interface
 Interfaces to isolated database and
web services :
public interface IEmailSource
{
IEnumerable<string> GetEmailAddresses();
}
public interface IEmailDataStore
{
void SaveEmailAddresses(IEnumerable<string> emailAddresses);
}

22. Example of using Interface
 Mock classes :
public class MockEmailSource : IEmailSource
{
public IEnumerable<string> EmailAddressesToReturn { get; set; }
public IEnumerable<string> GetEmailAddresses()
{
return EmailAddressesToReturn;
}
}
public class MockEmailDataStore : IEmailDataStore
{
public IEnumerable<string> SavedEmailAddresses { get; set; }
public void SaveEmailAddresses(IEnumerable<string> emailAddresses)
{
SavedEmailAddresses = emailAddresses;
}
}

23. Mocking Frameworks
 Nmock
 Moq
 Rhino Mocks
 TypeMock
 EasyMock.Net