Testing Strategies

COMP1 – Section 4.2. Testing

Aims

At the end of this lesson you will be able to:

Explain different testing strategies Design and carry out basic testing Demonstrate the importance of

validation of input data

What can you test?

If you planned to build a car you could plan the tests to perform BEFORE you even put a nut and bolt together I want the car to stop from 60mph to 0 in

3 seconds I want the car to accelerate from 0 – 60 in

10 seconds You could create hundreds of tests Only AFTER you had built the car could

you implement the tests

Your program

The same is true of your program or project (A2)

Create a test PLAN during the design stage

Then: Create the projectThen: Test the program/project using your

test plan

Testing is a big area(as is Texas)

You can not hope to test all the possible combinations in your program

For example for one input variable you could enter ever possible combination of keyboard characters, clearly infeasible (and a bit silly)

We can split up the problem. This makes it simpler to manage.

Test Plan

Think about the things your program will be doing:

Reacting to user input Choose from menus Producing outputs like invoices

Processing calculations Are the monetary values calculated correctly Does the graph show the correct figures

Validating input See 4.1. validation and error handling Give some examples.

Format of the USER test plan

User testing

Test no

Test data Reason for choice of test data

Expected Outcome

Actual Outcome

Comment

1 Choose menu option ‘A’ for flights only’

To see if use can make choice

Go to correct holiday calculator

2

CALCULATION test planTest no

Test data Reason for choice of test data

Expected Outcome

Actual Outcome

7 (HolPrices added) and divided by noOfHols:1+2+3/3

To see if the average price of holidays is calculated correctly

23 – need to divide by No of items added to get correct result. See screen prints 5 and 6.

8 People * HolPrice 3 * 30

Cost of holidays calculated correctly

90 Holiday cost calculated correctlySee screen print 1

Note the test numbers follow on from the user tests

Note, your program does not have to work correctly in every way. SOME errors are

permitted. It is actually good to show that some areas do not work but explain how you go about solving these problems.

VALIDATION test planTest no

Test data Expected outcome

Reason for choice of test data

Actual Outcome

Comment

17 Age:-1 rejected Below acceptable value - boundary

18 Age:10000 rejected Above acceptable value - invalid

19 Age: Blank no-input

Rejected Cell contains no data - erroneous

20 Age:110 Accepted Upper bound of acceptable data

21 Age:1 Accepted Lower bound of acceptable data

22 Age:25 Accepted Normal data - valid

23 Age: A Rejected Erroneous data - invalid

Note the test numbers follow on from the calculation tests

Testing strategies

Black box testing White box testing

Alpha testing Beta testing

Black box testing

Referred to as ‘functional testing’ Carried out independently of the

code used in the program. Create test data that covers all the

inputs and outputs and program functions by looking at the specification

Examples?

White box testing

Referred to as ‘structural testing’ Program code is studied and tests

are devised which test each possible path at least once.

Weakness: you cannot test what is not there!!!

Examples?

Alpha Testing

Carried out by the software developer’s in-house testing team.

Reveals errors and omissions is systems requirements definition.

Beta Testing

Software is tested by a number of potential users who agree to use the system and report any problems.

Activity in pairs:

Download testing template.doc from Moodle->COMP1->4.2. Testing

Decide on test data Carry out testing with neighbour –

SWAP seats! Record outcomes! If you have extra time!: Download zip file from Moodle in 4.2. Use 4.2. Testing of Insurance calculator

program.doc to test program

Checking your newly gained knowledge:

testing strategies – examples? Test plan and recording tests –What

needs testing? validation of input data – Why

important?

Homework

COMP1-4.1.A. Validation. Question 1 in validation and error handling section from the Book on page 225.

By Tuesday