2. Introduction to Software Testing

Question 1

What does testing check?

Answer 1

Testing checks whether the program implementation agrees with the program specification

Question 2

Automated vs Manual testing

Answer 2

Automated Testing

• Find bugs more quickly
• No need to write tests
• If software changes, no need to maintain tests

Manual Testing

• Efficient test suite
• Potentially better coverage

Question 3

Black-box vs White-box testing

Answer 3

Black-box:

• Tester knows nothing about the tested programs
• Can work with code that cannot be modified
• Does not need to analyze or study code
• Code can be in any format (managed binary, obfuscated)

White-box:

• Tester can see the internal details of the program being tested
• Efficient test suite
• Potentially better coverage

Question 4

What is a pre-condition? What is a post-condition?

Answer 4

A pre-condition is a predicate that is assumed to hold before a function executes.

A post-condition is a predicate that is expected to hold after a function executes, whenever the pre-condition also holds.

Question 5

What are the types of code coverage?

Answer 5

• Function coverage: which functions were called?
• Statement coverage: which statements were executed?
• Branch coverage: which branches were taken?
• Others include line coverage, condition coverage, basic block coverage, path coverage…

Question 6

What is mutation analysis?

Answer 6

Test variations (mutants) of the program (e.g., replace x > 0 with x < 0). If the test suite is good, it should report failed tests in the mutants.