Testing and maintainability

Question 1

Why are programs tested?

Answer 1

to ensure that they are robust, produce the expected results, and can handle malicious users

Question 2

destructive tests

Answer 2

tests should be destructive and try to find errors rather than just proving the program works

Question 3

iterative tests

Answer 3

carried out when the software is being developed

tests are carried out on each module and the results inform further developments

code is fixed and tested again (iterates) until the module works as intended

Question 4

final/terminal testing

Answer 4

carried out once the software has been developed and all modules are complete

program tested as a whole to ensure that it functions as intended

alpha testing is done by the developers, and beta testing by potential users of the software

Question 5

types of test data (3)

Answer 5

normal data

boundary data

erroneous data

Question 6

normal data

Answer 6

tests the software under normal working conditions

Question 7

boundary/extreme data

Answer 7

tests the software under extreme conditions

uses valid data that falls at the boundary of any possible ranges

e.g. will test that length and range checks are functioning correctly

if a program has variable < 1 the test data could be 1

Question 8

erroneous data

Answer 8

tests how the software deals with incorrect inputs that may be entered deliberately or by mistake

the program should have routines to deal with them, and inform the user that the data is invalid

Question 9

test plan

Answer 9

a list of what is to be tested and how it is to be tested

Question 10

testing tables

Answer 10

tests are laid out in a testing table

• test number
• description of what it intends to check
• test data
• type of test
• expected outcome
• actual outcome

Question 11

syntax errors

Answer 11

error in a program resulting from code not following syntax rules governing how to write statements in a programming language

grammatical mistakes in code

can be prevented by using an IDE (integrated development environment)

e.g.
misspellings
using a variable before it has been declared

Question 12

logic errors

Answer 12

error in a program which does not cause a program to crash but causes unexpected results

trace tables help to identify logic errors

e.g.
wrong type of Boolean operator (AND/OR/NOT)
loops that run forever

Question 13

maintainability for testing

Answer 13

• program code should be easy to follow and understand in case errors have to be corrected, or changes have to be made
• explanations should be added to explain the code (comments are shown using //)
• code that depends on a previous statement should be indented
• it is easier to follow/understand a program when meaningful identifiers have been used