Lecture 18: Software Testing

Question 1

What is testing?

Answer 1

A collection of guidelines, methodologies, and tools for examining our products for errors and inconsistencies in stated requirements, implied requirements, and missing requirements

Question 2

Whose job is it to test?

Answer 2

Developers, test engineers, customers, and other stakeholders all have responsibilities

Question 3

Debugging vs. Testing

Answer 3

Testing uncovers the faults, debugging diagnoses and removes faults

Question 4

What are the types of faults?

Answer 4

Omission: Requirements we forgot to include
Commission: Requirements we failed to implement correctly

Question 5

What is the functional testing classification?

Answer 5

Black box approach
Concerned with system functionality and features, not concerned with implementation details
Takes the view of user or client

Question 6

What is correctness testing? (functional)

Answer 6

Be sure that the systems meets all of its stated and implied requirements

Question 7

What is performance testing? (functional)

Answer 7

Determine how well the system meets all of its stated and implied requirements
Determines resource limitations and inefficiencies of the system

Question 8

What is stress testing? (functional)

Answer 8

Uncover any hidden faults which may cause the system to be unreliable under high loads or partial system failures

Question 9

What is the structural testing classification?

Answer 9

White box approach
Concerned with implementation details
Takes the viewpoint of the developer
Tends to find errors of commission, not omission

Question 10

What is statement coverage testing? (structural)

Answer 10

Be sure that all parts (hardware) and all statements (software) are used or executed at least once

Question 11

What is decision coverage testing? (structural)

Answer 11

Check to be sure all decision points are exercised at least once for each possible outcome

Question 12

What is path coverage testing? (structural)

Answer 12

Ensure all possible paths through the decision points are used at least once

Question 13

Will testing in the real world assure us (100%) that there are no more faults?

Answer 13

No, our goal should be to provide enough (risk based) testing to ensure the probability of failure is low enough to be acceptable

Question 14

What is path testing?

Answer 14

Based on selecting paths through the software, some % of full path coverage
Good for module level testing

Question 15

What is transaction flow testing?

Answer 15

Traces the objects from their birth to their death, and possibly beyond, through the system

Question 16

What is data flow testing?

Answer 16

Based on tracing data through the system
Very useful on multiprocessor and parallel programming systems
Looks for initialization and data flow anomalies

Question 17

What is syntax testing?

Answer 17

GIGo (Garbage in, garbage out)
Used to test the program and data translation functions of the system

Question 18

What is state testing?

Answer 18

Based on finite state or petri net models
Trace state transition behavior of the system
Useful for testing real time systems

Question 19

What is black box testing?

Answer 19

Cannot see source code, internal data, design documentation

Question 19

What is domain (random) testing?

Answer 19

Requires domain knowledge of how the system is to be used
Input data is either pre-selected or drawn at random

Question 19

What is mutation testing?

Answer 19

Test data sets are good if they can detect small random changes to the software
Plant errors in the code and check to see they are detected

Question 20

What is white box testing?

Answer 20

Testers have access to system internals