Dynamic Testing

DYNAMIC TESTING
Hoang V. Nguyen
startnewday85@gmail.com
startnewday85.blogspot.com
Dept. of Computer Science – FIT - HUA

Tester Training Course

User Acceptance
requirements Testing

System
System Testing
requirements

Integration
Global Design
Testing

Detailed Design Unit Testing

implementation

Tester Training Course 2011

 Systematic approach

 Non systematic approach


 Identify Test conditions
 Specify Test cases
 Specify Test Procedures
• is also referred as test script


 Testing may be performed with varying
degrees of formality
• Test Design Specification(IEEE 829)/ Test Condition
Specification

• Test Case Specification

• Test Procedure Specification/ Test Script
• Manual
• Automatic


 Provides a quantitative measure of the
quality of the testing that has been done
 By measuring what has been achieved
 Provides a way of estimating how much
more testing needs to be done.
 Can be applied to any systematic approach


 Test requirements/ test inventory/ test
objectives
 Designed based on test basis
 Traceability
 Must be prioritized


 Test Data
• inputs,
• pre-conditions,
• expected results,
• post-conditions

 Exhaustive Testing is impractical
• must select a subset of all possible test cases


 a procedure for selecting test cases
 a way deriving good test cases
 a way objectively measuring a test effort
 maximize possibility faults found, minimize
time and resources


 Different people: similar probability find faults
• gain some independence of thought

 Effective testing: find more faults
• focus attention on specific types of fault
• know you're testing the right thing

 Efficient testing: find faults with less effort
• avoid duplication
• systematic techniques are measurable


 Systematic approach
• Specification-based or black-box
• Structure-based or white-box

 Experience based approach
• Error Guessing
• Exploratory testing


 Specification-based approach
• based on specifications and models of what the
system should do
• do not care how do

 Some techniques
• Equivalence partitioning
• Boundary value analysis
• Decision table testing
• State transition testing
• Use case testing


 divide the test case space into
areas(partitions)
• inputs
• outputs
• conditions

 In an area, if one element works
correctly, all will work correctly
 One from each partition better than
all from one


Name From 18
Age to 50

Invalid valid Invalid
18 50

==> Test cases: 10, 20, 60, abc

18 50

 Faults tend to lurk near boundaries
 Good place to look for faults
 Test values on both sides of boundaries


From 3 to 50
characters

Name From 18 to
50
Age


 Number of characters
3 50

 Valid characters A-Z, a-z,
Invalid
space

Test Condition Valid Partition Invalid Valid Boundary Invalid
Partition Boundary
Name Field 3-50 chars <3 chars 3 chars 2 chars
>50 chars 50 chars 51 chars
valid chars invalid chars


18 50

Test Condition Valid Partition Invalid Partition Valid Boundary Invalid
Boundary
Age Field 18-50 <18 18 17
>50 50 51
Non numeric


Question
In a Examination a candidate has to score minimum 24
marks in order to clear the exam. The maximum that
he can score is 40 marks. Identify the Valid
Equivalance values if the student clears exam.

22, 23, 26

21, 39, 40

29, 30, 31

0, 15, 22


Question
Boundary value testing

Is the same as equivalence partitioning tests

Test boundary conditions on, below and above the
edges of input and output equivalence classes

Tests combinations of input circumstances

Is used in white box testing strategy


Question
Equivalence testing divides the input
domain into classes of data from which test
cases can be derived to reduce the total
number of test cases that must be
developed.

True

False


Question
An input field takes the year of birth
between 1900 and 2004. The boundary
values for testing this field are

0, 1900, 2004, 2005

1900, 2004

1989, 1900, 2004, 2005

1989, 1900, 1901, 2003, 2004, 2005


 Some software app, business rules can
be very complex
 Decision table a good method to
describe complex business rules
Business Rule Business Rule Business Rule Business Rule
1 2 3 4
Condition 1 T T T F
Condition 2 T F F T
Condition 3 T _ T T
Action 1 Y N N N
Action 2 N N Y N


Given the following decision table: Which of the
following test cases and expected results is VALID?
Rule 1 Rule 2 Rule 3 Rule 4
Age <21 yrs 21-29 yrs 30-50 yrs >50 yrs
Insurance class A A or B B, C or D C or D
Premium 100 90 70 70
Excess 2,500 2,500 500 1000

23 year old in insurance class A Premium is 0 and excess is,500.

51 year old in insurance class C Premium is 0 and excess is 00.

31 year old in insurance class B Premium is 0 and excess is ,500.

43 year old in insurance class C Premium is 0 and excess is ,000.


A supermarket has a loyalty scheme that is offered to all
customers. Loyalty cardholders enjoy the benefits of either
additional discounts on all purchases (rule 3) or the
acquisition of loyalty points (rule 4), which can be converted
into vouchers for the supermarket or to equivalent points in
schemes run by partners. Customers without a loyalty card
receive an additional discount only if they spend more than
£100 on any one visit to the store (rule 2), otherwise only
the special offers offered to all customers apply (rule 1).


Rule 1 Rule 2 Rule 3 Rule 4
Customer without loyalty card T T F F
Customer with loyalty card F F T T
Extra discount selected _ _ T F
Spend > £100 F T _ _
No discount T F F F
Extra discount F T T F
Loyalty points F F F T
 Create at least one test case for each rule
• Conditions specify inputs
• Actions specify outputs


 based on state transition diagram
 Example: ATM State Transition
NOT OK

Start 2nd try

3rd try
1st try

NOT OK

Access
wait Eat
to
for PIN card
Account


 Four different levels of coverage
• State Coverage
• Event Coverage
• Path coverage
• Transition coverage


 State Coverage
 Generally this is a weak level of test coverage

2 NOT OK
1
Start 2nd try

3rd try
1st try

NOT OK

Access
wait Eat
to
for PIN card
Account


 Event Coverage
 also is a weak level of coverage

2 NOT OK
1
Start 2nd try

3rd try
1st try

NOT OK

Access
wait Eat
to
for PIN card
Account


 Path Coverage
• is the strongest level of coverage
• but may not be feasible
• if the state transition diagram has loops, then the
number of possible paths may be infinite


 Transition Coverage
• good level of coverage with out generating large
numbers of tests
• this level is generally the one recommended
NOT OK

Start 2nd try

3rd try
1st try

NOT OK

Access
wait Eat
to
for PIN card
Account

 To exercise a complete process flow
 At least one test case for the main
success scenario
 At least one test case for each extension


 Test oracle

 Partial oracle


 Based on “What”, with out “How”
 Test cases can be designed:
• Input/output variables with their ranges and
boundaries
• Business rules
• System behaviors
• System’s functionalities from start to finish


Question
Purpose of test design technique is

Identifying test conditions only, not Identifying test
cases

Identifying test conditions and Identifying test cases

Not Identifying test conditions, Identifying test
cases only

Identifying test conditions or Identifying test cases


Question
’X’ has given a data on a person age, which
should be between 1 to 99. Using BVA which is
the appropriate one

0, 1, 2, 99

1, 99, 100, 98

0, 1, 99, 100

-1, 0, 1, 99


Given the following state diagram: Which of the
following series of state transitions? S1 S0 S1 S2 S0

D, A, B

A, B, C, D

D, A, B, C

A, B, C


Question
Which type of test design techniques does the
following statement best describe a procedure to
derive test cases based on the specification of a
component?

White Box Techniques

Black Box Techniques

Glass Box Techniques

Experience Based Techniques


Given the following state diagram: Which of the following
series of state transitions contains an invalid transition
which may be indicate a fault in the system design?

Login Browse Basket Checkout Basket Checkout Pay Logout.

Login Browse Basket Checkout Pay Logout.

Login Browse Basket Checkout Basket Logout.

Login Browse Basket Browse Basket Checkout Pay Logout.


Question
Which of the following is MOST characteristic of
specification based(black-box)

Test cases can be easily automated

Test cases are independent of each other

Test cases are derived systematically from models of
the system

Test cases are derived systematically from the
delivered code


Question
Use cases can be performed to test

Performance testing

Business scenarios

Static testing

Unit testing


Question
Which is NOT a test oracle

The existing system(For a benchmark)

Indinidual’s knowlege

The code

User manual


Question
The Test Cases Derived from use cases

Are most useful in uncovering defects in the process
flows during real world use of the system

Are most useful in uncovering defects in the process
flows during the testing use of the system

Are most useful in covering the defects in the
process flows during real world use of the system

Are most useful in covering the defects at the
Integration Level


 Structure-based approach
• based on structures of system or component
• also called glass-box techniques

 What we may be interested in structures
• Component level: program structures
• Integration level: the way components interact with
others
• System level: how user will interact with the system


 Statement Testing
 Decision Testing
 Path Testing


 Design test cases based on what
statements which should be exercised
 Statement coverage
• percentage of executable statements exercised

number of statements exercise
• =
total number of statements

• is normally measured by a software tool
• typical ad hoc testing achieves 60 – 75%


1 Program Coverage Example
2 A, X: Integer
3 Begin
4 Read A
5 Read X
6 If A > 1 AND X = 2 Then
7 X = X/A
8 Endif
9 If A = 2 OR X = 2 Then
10 X = X + 1
11 Endif
12 End
The number of executable statements: 6
Test case 1: A=1, X=2; 4/6 or 67%

Test case 1: A=4, X=2; 6/6 or 100%

1 Program BestInterest
2 Interest, Base Rate, Balance: Real
3 Begin
4 Base Rate = 0.035
5 Interest = Base Rate
6 Read (Balance)
7 If Balance > 1000 Then
8 Interest = Interest + 0.005
9 If Balance < 10000 Then
11 Else
13 Endif
14 Endif
15 Balance = Balance × (1 + Interest)
16 End

What test cases to achieve 100 percent
statement coverage

 Design test cases based on what decision
outcomes which should be exercised
 same as Branch Testing
 Decision coverage
• percentage of decision outcomes exercised

number of decision outcome exercised
• =
total number of decision outcomes

• is normally measured by a software tool
• typical ad hoc testing achieves 40 – 60%

1 Program BestInterest
2 Interest, Base Rate, Balance: Real
3 Begin
4 Base Rate = 0.035
5 Interest = Base Rate
6 Read (Balance)
7 If Balance > 1000 Then
9 If Balance < 10000 Then
11 Else
13 Endif
14 Endif
15 Balance = Balance × (1 + Interest)
16 End

What test cases to achieve 100 percent decision
coverage

1 float dc(int a,b,c,d,h)
2 Begin
3 float r
4 If a=0 Then return 0
5 Endif
6 int f=0;
7 If (a=b) or ((c=d) and check(h))
Then
8 f=f+1;
9 Endif
10 f=f+1;
11 return 1/f
12 End

What test cases to achieve 100 percent decision
coverage

 Design test cases based on Boolean sub-
expression (BsE)
 Condition coverage
• percentage of Boolean sub-expression outcomes
exercised

number of BsE outcome exercised
• =
total number of BsE outcomes

• There are no industry standard objectives for
condition coverage


 Example
7 If (a=b) or ((c=d) and check(h)) Then

Predicate True False
a=b Test case 1 Test case 2
dc(1,1,x,y,z) dc(1,2,x,y,z)
c=d Test case 3 Test case 2
dc(1,2,2,2,z) dc(1,2,1,2,z)
check(h) Test case 3 Test case 4
dc(1,2, 2,2,z) dc(1,2, 2,2, z’)


 Design test cases based on what paths
which should be exercised
 Path coverage
• percentage of paths exercised

number of paths exercised
• =
total number of paths


1 2 3 4

1 2 1 2 1 2 3
?

? ? ? ?

?


1 2 3 4 5 6 7 8 ….

for as many times as it
is possible to go round
?
the loop (this can be
unlimited, i.e. infinite)


Question
If the pseudo code below were a programming language,
how many tests are required to achieve 100% statement
coverage?

1 If x=3 then
1
2 Display_messageX;
3 If y=2 then
2
4 Display_messageY;
5 Else
3
6 Display_messageZ;
7 EndIf
4
8 Else
9 Display_messageZ;
10 EndIf


Question
If the pseudo code below were a programming language,
how many tests are required to achieve 100% decision
coverage?
1 Program AgeCheck
2 CandidateAge: Integer;
3 Begin
4 Read(CandidateAge) 1
5 If CandidateAge < 18 Then
6 Print (“Candidate is too young”) 2
7 Else
8 If CandidateAge > 30 Then
9 Print (“Candidate is too old”) 3
10 Else
11 Print(“Candidate may join Club 18–30”)
12 Endif 4
13 Endif
14 End


 is an important measure in systematic
approach
 But
• Coverage techniques measure only one dimension
• measures only what has written

In practice, are always multi-dimension and
have something which have not been written


Question
Which of the following is NOT true
of test coverage criteria?

Test coverage criteria can be measured in terms of
items exercised by a test suite

A measure of test coverage criteria is the percentage
of faults found

A measure of test coverage criteria is the percentage
of user requirements covered

Test coverage criteria are often used when
specifying test completion criteria


 Unscripted testing
 Experience based approach
 Some techniques
• Error guessing
• Exploratory testing

A testing approach that is only rigorous,
thorough and systematic is in complete


 no rules, no script
 situations in which the software may
not be able to cope are identified based
on experience(feel)
 Consider:
• past failures
• brain storming
• intuition
• “what is the craziest thing we can do”


 always worth including
 after systematic techniques have been
used
 can find some faults that systematic
techniques can miss
 a ‘mopping up’ approach
 supplements systematic techniques


Details will be focused in Agile testing lectures


Question
A test design technique is

A process for determining expected outputs

A process for selecting test cases

A way to measure the quality of software

A way to measure in a test plan what has to be done


Question
Error guessing

A supplements formal test design techniques

Can only be used in component, integration and
system testing

Is only performed in user acceptance testing

Is not repeatable and should not be used


Question
Error guessing is

An appropriate way of deriving system tests

Only used if good requirements are not available

Only used when good requirements are available

The most appropriate way of deriving system tests


Question
Random testing

A black-box testing technique

Program is tested randomly sampling the input

Both A and B

None of the above


Dynamic Testing

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