Lecture 9: Software Testing

Question 1

What is Software failure process?

Answer 1

Map into unacceptable output sequences

Question 2

What is operational environment?

Answer 2

Measures the reliability of software products and its operational environment

Question 3

What must test cases consist of?

Answer 3

• Description of input data
• Precise description of correct output for the input data
• The results of the tests should be checked

Question 4

Test cases should be written for?

Answer 4

• Valid and expected input conditions
• Invalid and unexpected ones

Question 5

What must you check in test cases?

Answer 5

• That the program does not do what it is not supposed to do
• Does what it supposed to do

Question 6

List the three forms of software testing

Answer 6

• By the scope of testing
• By the knowledge of the internal structure
• By the goal testing

Question 7

Elaborate the scope of testing

Answer 7

• Unit testing
• Integration testing
• System testing

Question 8

Elaborate the knowledge of internal structure

Answer 8

• Black box: the internals of the tested software are NOT known
• White box: the internals of the tested software ARE known and **made use of **

Question 9

Elaboate by the goal testing

Answer 9

• Assessment: reliability, performance, resilience
• Debugging: fault, bugs finding

Question 10

What is black box testing?

Answer 10

• Done in the user perspective not the designer: mainly the specification
• Tests every possible **input/demand **
• Uses sampling from the input/demand

Question 11

What is white box testing?

Answer 11

• Test cases are derived by examining program’s logic
• Goal to have exhaustive path testing = Code coverage

Question 12

What is software testing objective?

Answer 12

• Performance related testing
• Reliability related testing
- Debugging – selecting test cases that maximise the like hood of activating faults
- Assurance that a software is good enough
• Usability testing

Question 13

How can software reliability affect the market advantage?

Answer 13

• Releasing a software that is unreliable will receive poor reviews
• Can be costly
• Spending too much time improving reliability pre-release prevents vendors from gaining market advantage

Question 14

What is unit testing?

Answer 14

• Process of testing a software in different areas/units whereby verifying the functions work as expected
• A technique used to debug

Question 15

What must test cases show?

Answer 15

• What and when it is expected to do and if the user had any problems

Question 16

What are the 2 unit types of testing?

Answer 16

• Should show that the component works as expected
• Test case should show the abnormal inputs to properly checking for any problems with the component

Question 17

What does a test coverage of a class involve?

Answer 17

• Testing all the operations associated with an object
• Finding possible states

Question 18

What is component testing?

Answer 18

• Made up of interacting objects
• Are accessed through component interfaces
• Should focus on showing that the component interface behaves accordingly to its specification

• Component testing

                                     - Errors and misunderstanding etc.
         - Interface failures

Question 19

What does software testing involve?

Answer 19

• Tested during development which involves testing the components to create a version of the system and testing the entire integrated system
• Focuses on the interaction of the components
• Checks that the components are compatible and interacting correctly
• Tests the behaviour of the system
• Developed by a set of separate system testing team/sub-teams

Question 20

What is use case testing?

Answer 20

Developed to identify the system interactions used as a basis for system testing

Question 21

Testing policies check what?

Answer 21

The required system test coverage includes EXAMPLES:
• Accessing menus
• Text formatting
• Correct/incorrect input

Question 22

What is Test driven development?

Answer 22

TEST-DRIVEN DEVELOPMENT is an approach to program development in which you inter-leave testing and code development
• Develop the code incrementally until one has passed the test before moving to the next increment

Question 23

What are the benefits of test-driven development?

Answer 23

• Code coverage
• Regression testing
• Simplified debugging
• System documentation

Question 24

Whats the other forms of testing?

Answer 24

Is to check that previously working functionality still works, after changes elsewhere in the system is made

All tests are re-run every time a change is made

Question 25

What's release testing?

Answer 25

Testing that is intended to be used outside of the development team by **convincing the supplier that it is good enough use** **Black-box testing** which focuses on the specification

Question 26

What's user testing?

Answer 26

Get user and customer’s feedback and advice • Essential after doing a release testing

Question 27

What are the forms of user testing?

Answer 27

• **Alpha testing** - Working with the development team to test the software at the _developer’s site_ • **Beta testing** - Made available to users to _allow experiment and raise any problems_ that they may discover • **Acceptance testing** - Customers test to decide if the software is ready and accepted by developers and deployed to customers- used for _bespoke systems _

Question 28

What's statistical testing?

Answer 28

Involves exercising the program by randomly generating test cases to see if it has reached the required level of quality measuring: • **Reliability** and the **performance** • Test cases for defect testing are a typical of actual usage • Targets the **anticipated environment**

Question 29

What does statistical testing activites esabilsh and test?

Answer 29

Establishes the **operational profile** Needed to generate random test cases Testing the system known as “**Oracle**” testing between test cases

Question 30

Whats inference procedure?

Answer 30

* Performance measures * Reliability measures

Question 31

Whats Statistical testing for reliability?

Answer 31

* Responsible for handling a number of **test cases correctly and others incorrectly** * The Oracle has to be able to **handle a number of tests**

Question 32

How do you test Oracle problem?

Answer 32

Building a good Oracle solution: • Limiting coverage by **detecting crashes** • Implements **plausibility checks**