Software testing is a process of analyzing a software item to detect the differences between observed and expected behavior

Levels of Testing

• unit testing: tests if individual modules of the source code are working properly
  • done by developers
• regression testing: tests if previously tested software still works properly after a change
  • done by dev or testers
• integration testing: tests the interface between two or more unit tested modules
  • done by testers
• system testing: tests the fully integrated system using end to end scenarios
  • done by testers
• acceptance testing: tests user requirements on a release candidate of the systems
  • done by users

Isolating the Item-Under-Test(IUT)

Isolating the Item-Under-Test (IUT) is an essential strategy in software testing, particularly in the stages of unit and integration testing. This isolation helps in reducing uncertainties and dependencies, allowing testers to focus on the functionality and performance of the specific item being tested. Two key tools used in this process are the Test Stub and the Test Driver:

• Test Stub: used to simulate the behavior of called items not yet integrated with the IUT
• Test Driver: used to test the IUT when the callers are not available yet

They are both instrumental in a controlled and efficient testing process. They allow for the early detection of defects and enable testing in a modular fashion.

Test Driven Development

Test-Driven Development (TDD) is a software development methodology that emphasizes writing automated tests before writing the actual code. This approach inverts traditional development processes by prioritizing testing at the outset.

• Focus developer to write testable code
• can be applied at any level, but most common for unit testing
• outcome is compared to the expected result (gold standard or test oracle)

Control Flow Test Coverage