Sample Problems for Testing
• For “Program” Level Testing:
– Triangle
– Next Date
– Sales Commission
• For “System” Level Testing:
–
–
–
–
SATM system
Currency conversion
Windshield Wiper
Garage Door Controller
These 7 problems will
be used throughout the
remainder of the course
as examples for different
testing techniques
1. Triangle Problem
• Problem (Requirements) Statement:
– Write me a program that
• will accept 3 numbers which represent the 3 sides of a
triangle.
Problem:
• evaluate the inputs and determine if
relating a) inputs to
–
–
–
–
It is a triangle
an isosceles triangle
an equilateral triangle
a scalene triangle
b) outputs based
on input validity &
input relationship
• Output the answer
Look at this requirement statement and identify areas of potential problem if
you were writing the program - - - anything more if you were testing this?
(would you ensure that the outputs are tested via “partitioned” set?)
Your textbook has an “improved” version of the requirement.
1. Triangle Problem
• The triangle problem is the most widely used example in
software testing literature.
• Simple version: The triangle program accepts three
integers, a, b, and c, as input. These are taken to be sides
of a triangle. The output of the program is the type of
triangle determined by the three sides: Equilateral,
Isosceles, Scalene, or Not A Triangle.
1. Triangle Problem
• Improved version: “Simple version” plus better definition
of inputs:
• The integers a, b, and c must satisfy the following
conditions:
•
c1.
1 ≤ a ≤ 200 c4.
a<b+c
•
c2.
1 ≤ b ≤ 200 c5.
b<a+c
•
c3.
1 ≤ c ≤ 200 c6.
c<a+b
1. Triangle Problem
• If an input value fails any of conditions c1, c2, or c3, the
program notes this with an output message, for example,
“Value of b is not in the range of permitted values.” If
values of a, b, and c satisfy conditions c1, c2, and c3, one
of four mutually exclusive outputs is given:
1. If all three sides are equal, the program output is
Equilateral.
2. If exactly one pair of sides is equal, the program output is
Isosceles.
3. If no pair of sides is equal, the program output is Scalene.
4. If any of conditions c4, c5, and c6 is not met, the program
output is NotATriangle
1. Triangle Problem Discussion
• Problems persist! What output is expected for the input set
(2, 2, 5)?
• Isosceles because a = b?
• NotATriangle because c > a+b?
• Fix it (sometimes testers must also be specifiers!)
• The Really Final Version: “Improved version” plus better
definition of outputs.
2. Next Date Problem
• Problem (Requirements) Statement:
– Write me a program that
• will accept 3 numbers which represent the day, month, and
year of a calendar date
• evaluate the inputs and determine
– The next day of the date represented by the input
• output the next day answer
Problem:
relating inputs to
outputs based
on input validity &
input relationship &
“complex” data relationships
Look at this requirement statement and identify areas of potential problem if
you were writing the program - - - anything more if you were testing this?
2. Next Date Problem
• NextDate is a function of three variables: month, date, and
year. It returns the date of the day after the input date. The
month, date, and year variables have integer values
subject to these conditions:
•
c1.
1 ≤ month ≤12
•
c2.
1 ≤ day ≤ 31
•
c3.
1812 ≤ year ≤ 2012
• If any of conditions c1, c2, or c3 fails, NextDate produces
an output indicating the corresponding variable has an
out-of-range value — for example, “Value of month not in
the range 1..12”. Because numerous invalid day–month–
year combinations exist, NextDate collapses these into
one message: “Invalid Input Date.”
3. Monthly Sales Commission Problem
• Problem (Requirements) Statement:
– Write me a program that
• will accept 3 numbers which represent the number of locks,
number of stocks, and number of barrels of a riflesold at each town
during the month
• Will accept a number, -1, for locks to represent the “end” of
monthly sales so sales commission can be computed
• evaluate the inputs and determine the monthly sales commission
as follows:
– each lock price is $45; each stock price is $30; and each barrel price is
$25
– sales person is paid 10% of total sales for the first $1000; 15% on the
next $800; and 20% in excess of $1800
• output the sales commission
• Some sales “limitations” exist
Problem:
Input – store - compute -output
– Must sell one complete rifle
– Monthly sales (production limit) must be:
» # of locks <71
» # of stocks < 81
» # of barrels < 91
Look at this requirement statement and identify areas of potential problem if
you were writing the program - - - anything more if you were testing this?
4. SATM System Problem
• Problem (Requirements) Statement:
– Develop part (a component) of an automatic teller system that:
•
•
•
•
Displays a “welcome screen” with a simple instruction to insert ATM card
Validates the ATM card. If invalid keeps it (with a message); otherwise goes on
Asks for and validates a personal id number ( only up to 3 times)
If valid, three “activity” options are presented:
– Check the account balance
– Withdraw from the account
– Deposit into the account
• Once the option is selected, the customer is presented with and asked to choose
between a checking or a savings account
• For each of these 3 optional activities the customer account file is also updated
with
– Date of ATM access and
– Increment the number of times this account is accessed through ATM
4. SATM System Problem
Welcome to
Rock Solid Federal Credit Union
Please insert your ATM card
Printed Receipt
1
2
3
Card Slot
4
5
6
Enter
7
8
9
Clear
0
Cash Dispenser
Cancel
Deposit Slot
4. SATM System Problem (cont.)
– Requirements (cont.)
• If account balance is requested then a new balance is printed and the
customer is given a choice for more activities.
• For both withdrawal and deposit options, the customer is asked to key in
the amount
• For withdrawal, the minimum increment is $10. The customer account
will be updated, and the customer will be asked to take the cash from the
dispenser. In the event there is insufficient funds, the customer is asked
to re-key an amount
• For deposits, if the ATM terminal deposit is working (envelop exists and
slot moves), then the customer is asked to place the deposit in an
envelop and deposit through the ATM. Otherwise, the customer is told of
the problem and given a choice of other options.
• When customer activities are complete, a new balance is printed on the
receipt and a choice for more activities is given. If the customer chooses
more activity, he is returned to the 3 choices of activities again.
• If the customer has no more activity then a message for customer to take
both the receipt and the ATM card and the system ends.
This testing would be closer to a component or system test, after each unit
test is completed. How would divide the component into units for unit testing?
5. Currency Conversion Subsystem
• Problem (Requirements) Statement:
– Develop a GUI based sub-system that
• will accept US currency and convert it to:
–
–
–
–
Brazilian currency
Canadian currency
European community currency
Japanese currency
Note: more currencies than
the textbook
• use the exchange rate within the last 12 hours.
• Also allow the “reverse currency” computation
Look at this requirement statement and identify areas of potential problem if
you were writing the program - - - anything more if you were testing this?
5. Currency Conversion Subsystem
Currency Converter
U.S. Dollar amount
Equivalent in ...
Brazil
Compute
Canada
Clear
European community
Japan
Quit
6. Saturn Windshield Wiper Controller
• Problem (Requirements) Statement:
– Write me an “embedded” program that
• Controls the 4 speed settings of a windshield wiper:
–
–
–
–
Off
Intermittent
Low
High
OFF -> Wiper does not move
As a tester what needs to be considered?
- if wiper is not moving, then ?
• For “off”, the windshield wiper does not move
• For Intermittent setting, there are 3 “dial” sub-settings:
– 1 : wiper wipes 4 times per minute
– 2: wiper wipes 6 times per minute
– 3: wiper wipes 12 times per minute
• For Low, the wiper wipes 30 times per minute
• For High, the wiper wipes 60 times per minutes
Look at this requirement statement and identify areas of potential problem if
you were writing the program - - - anything more if you were testing this?
6. Saturn Windshield Wiper Controller
c1. Lever
OFF
INT
INT
INT
LOW
HIGH
c2. Dial
n/a
1
2
3
n/a
n/a
0
4
6
12
30
60
a1. Wiper speed
is…
7. The Garage Door Controller
(shown here as a SysML Context Diagram)
Digit
Keypad
Portable
Opener
48V DC
Power
Wall-mount
button
Light
Beam
Wireless
Receiver
Garage
Door
Controller
Extreme
Limit
Sensor
Drive
Motor
Lamp
Obstacle
(Resistance)
Sensor
110V AC
Power