TESTING

Question 1

What is Testing?

Answer 1

• Google says “Software testing is an investigation conducted to provide stakeholders with information about the quality of the product or service under test.”

Question 2

What testing cant do?

Hints: (Prove bug-free, Try all conditions)

Answer 2

• Prove the software is entirely bug-free
  o Certain bugs may only arise in certain situations.
  o Possible test data could be too large.
• Try all conditions the software might encounter
  o Sometimes difficult to trial in intended working environment.
  o Users might try to find new uses for the software which were not originally considered.
  o User errors could be difficult to predict.

Question 3

What are some things that can go wrong?

Answer 3

• Magnetic/electrical interference
• Memory corruption by other programs
• Network problems/data corruption
• Hardware faults
  o Modern hardware is incredibly reliable
  o However, safety-critical systems still compensate for the fact it may occur

Question 4

What is Test Driven Development?

Answer 4

• TDD is an alternative approach to programming.
• It comes from the agile software development methodologies.
• It is very different to the traditional, waterfall, approach where testing occurs after code is completed.

There are three phases

• Write a test (which will fail as there is no code to test) – the red phase.
• Write code to pass this test – the green phase.
• Refactor (rename, adjust, etc.)

The idea is that you write the tests before writing the code
- Think of the test as the formal specification.

Question 5

What TDD can’t do?

Answer 5

• TDD is no quick fix for a poor specification.
• TDD can help you write code which meets the existing specification.
• However, it cannot find what is missing from the specification, hence there is still the need for system testing and acceptance testing by the customer

Question 6

What is a Junit test?

Answer 6

• In general, in a test, we want to do some actions, then check that the system is in an expected state.
• We do this by writing normal code, then using assert statements to test that the actual state matches the expected state.