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1 USN 1 P E PESIT Bangalore South Campus Hosur road, 1km before Electronic City, Bengaluru -100 Department of Information Science & Engineering INTERNAL ASSESSMENT TEST 1 Date : 23/02/2016 Max Marks: 50 Subject & Code : Software Testing / 10IS65 Section: 6 th A & B Name of faculty: Mr. Animesh Giri Time: 8:30 AM 10:00 AM Note: ANSWER ANY FIVE FULL QUESTIONS REFER TEST CASE TEMPLATE PROVIDED TO TABULATE TEST CASES SOLUTION SCHEMA 1. a) Define Software Testing. What are the motivation behind usage of Equivalence Class testing and how does it addresses the problem observed in Boundary Value Analysis testing. (05 Marks) Answer: The use of equivalence classes as the basis for functional testing has two motivations: a. To have a sense of complete testing and b. To avoid redundancy The problems faced in BVA method are: The test cases generated by BVA method emphasize more on the extreme values of input variables. Hence, in BVA method serious gaps exist between test cases which does not results in a satisfactory testing. Moreover, it has an assumption that the input variables are truly independent, and when this assumption is not warranted, the method generates unsatisfactory test cases. The BVA test cases are obtained by holding the values of all but one variable at their nominal values, and letting that variable assume its extreme values. This results in redundant test cases at nominal values of variables. Both the problems faced in BVA test cases are overcome by Equivalence class test cases: Equivalence classes form partitions of an input set, where partitions refer to a collection of mutually disjoint subsets, the union of which is the entire set. This has two implications for testing: the fact that the entire set is represented provides a form of completeness, and The disjointedness ensures a form of non-redundancy.

2 b) Explain Structural testing (White Box) with diagram & list out its advantages; Highlight the drawbacks of Functional (Black Box) testing approach. (05 Marks) Answer: White box/structural/clear box testing: White- box testing (also known as clear box testing, glass box testing, and transparent box testing and structural testing) is a method of testing software that tests internal structures or workings of an application, as opposed to its functionality. Some structural testing methods are Path testing and dataflow testing. Fig: White box testing Functional testing has two distinct advantages: 1) They are independent of how the software is implemented, so if the implementation changes the test cases are still useful. 2) Test case development can occur in parallel with the implementation, there by reducing the overall project development interval. Drawbacks of functional testing approach: 1) Significant redundancies may exist among test cases, compounded by the possibility of gaps of untested software. 2) Because functional testing are based on the specified behavior, it is hard to imagine these methods identifying behaviors that are not on the specified behavior

3 2. Explain in detail the Worst-Case Boundary Value Analysis (WC-BVA) testing with appropriate diagram to generate test cases for a function of two variables, Also, List all the generated WC- BVA Test Cases. Finally tabulate 10 Unique Test Cases along with the expected output for Triangle Problem (10 Marks) Worst Case Testing: Worst Case testing considers the five element set that contains the min, min+, nom, max- and max values for each variable. Cartesian product of these sets is taken to generate test cases. Worst case testing does not consider the single fault assumption of reliability theory. Worst case testing is clearly more thorough in the sense that boundary value analysis test cases are proper subset of worst-case test cases. Worst-case test cases for a function of n variables generate 5 n test cases. Worst-case test cases for a function of two variables is shown in Figure-2.4 x 2 d c a b x 1 Case a b c Expected Output Isosceles Isosceles

4 Equilateral Isosceles Not A Triangle Isosceles Isosceles 3. Tabulate 10 each unique Test Case along with the expected output by applying Robust BVA & Worst BVA approach. Mention the boundary for each variables used for the below mentioned examples. i) NextDate Function ii) Commission Problem (10 Marks) Answer: Next Date Function: NextDate is a function of three variables: month, day, and year. It returns the date if the day after the input date. The month, day, and year variables have integer values subject to these conditions: c1. 1<=month<=12 c2. 1<= day<=31 c <=year<=2012 NextDate function Boundary Value Analysis Test Cases Case month day year Expected Output june 16, june 16, june 16,1912

5 june 16, june 16, june 2, june 3,1912 Commission Problem Output Boundary Value Analysis Test Cases: Case Locks Stocks Barrels Sales Commission Comment Output minimum Output minimum Output minimum Output minimum Midpoint Border Point Border Point-

6 4. a) Explain in detail the Equivalence Class testing technique for a function of two variables generating all possible test cases considering i) Weak Normal Equivalence Class Testing ii) Strong Robust Equivalence Class Testing (05 Marks) b) Mention all possible Valid & Invalid Equivalence Classes for generating test cases for NextDate Function, and tabulate 10 unique test cases along with the expected output by applying Weak Normal & Strong Robust Equivalence Class Testing approach. (05 Marks) Answer:. Weak Normal Equivalence Class Testing: It identifies equivalence classes of valid values. Faults due to valid values of a single variable is detected (Single fault assumption). Weak normal class testing is accomplished by using one variable from each equivalence class (interval) in a test case. It is suitable for regression testing. Weak normal equivalence class test cases: where, a<=x1<=d, with intervals [a,b), [b,c), [c,d]; e<=x2<=g, with intervals [e,f), [f,g] are valid classes ii). Strong robust Equivalence Class Testing: In Strong robust Equivalence Class testing, the robust part comes from consideration of invalid values, and the strong part refers to the multiple fault assumption.

7 we obtain test cases from each element of the cartesian product of all the equivalence classes, as shown: where, a<=x1<=d, with intervals [a,b), [b,c), [c,d]; e<=x2<=g, with intervals [e,f), [f,g] x1<a, x1>d and x1<e, x2>g are valid classes and are invalid classes Problem Statement: NextDate is a function of three variables: month, day, and year. It returns the date if the day after the input date. The month, day, and year variables have integer values subject to these conditions: c1. 1<=month<=12 c2. 1<= day<=31 c <=year<=2012 Responses are defined for invalid values of the input variables for the day, month, and year and invalid combination of inputs. If any of the conditions c1, c2 and c3 fails, NextDate produces an output indicating the corresponding variable has an out of range value. The NextDate function illustrates very well the craft of choosing the underlying equivalence relation. NextDate is a function of three variables month, day, and year and these have intervals of valid values defined as follows: M1 = {month : 1 month 12} D1 = {day : 1 day 31} Y1 = {year : 1812 year 2012}

8 The invalid equivalence classes are: M2 = {month : month < 1} M3 = {month : month > 12} D2 = day : day < 1} D3 = {day : day>31} Y2 = {year : year < 1812} Y3 = {year : year >2012} Because the number of valid classes equals the number of independent variables, onl one weak normal equivalence class test case occurs, and it is identical to the strong normal equivalence class test case: Case ID Month Day Year Expected Output WN1, SN /16/1912 Here is the full set of weak robust test cases: Case ID Month Day Year Expected Output WR /16/1912 WR Value of month not in range 1 12 WR Value of month not in range 1 12 WR Value of day not in range 1 31 WR Value of day not in range 1 31 WR Value of year not in range WR Value of year not in range Here is one corner of the cube in 3-space of the additional strong robust equivalence class test cases: Case ID Month Day Year Expected Output SR Value of month not in range 1 12 SR Value of day not in range 1 31 SR Value of year not in range SR Value of day not in range 1 31 Value of month not in range 1 12

9 SR Value of day not in range 1 31 Value of year not in range SR Value of year not in range Value of month not in range 1 12 SR Value of month not in range 1 12 Value of day not in the range 1 31 Value of year not in range If we carefully choose the equivalence relation, the resulting equivalence classes will be more useful. We next reduce the granularity by focusing on more specific treatment. What must be done to an input date? If it is the last day of a month, the NextDate function will simple increment the day value. At the end of a month, the next day is 1 and the month is incremented. At the end of a year, both the day and month are reset to 1, and the year is incremented. Finally, the problem of leap year makes determining the last day of a month interesting. With all this in mind, we might postulate the following equivalence classes: M1 = {month : month has 30 days} M2 = {month : month has 31 days} M3 = {month : month is February} D1 = {day : 1 day 28} D2 = {day : day = 29} D3 = {day : day = 30} D4 = {day : day = 31} Y1 = {year : year = 2000} Y2 = {year : year is a non-century leap year} Y3 = {year : year is a common year} By choosing separate classes for 30- and 31- day months, we simplify the question of the last day of a month. By taking February as a separate class, we can give more attention to leap year questions. We also give special attention to day values: days in D1 are (nearly) always incremented, while days in D4 only have meaning for months in M2. Finally, we have three classes of years: the special case of the year 2000, leap years, and non-leap years. This is not a perfect set of equivalence classes, but its use will reveal many potential errors Equivalence Class Test Cases: Weak Normal Equivalence class test cases for the revised classes are: Case ID Month Day Year Expected Output WN /15/1912

10 WN /30/1996 WN Invalid input date WN Invalid input date Strong Normal Equivalence class test cases for the revised classes are: Case ID Month Day Year Expected Output SN /15/2000 SN /15/1996 SN /15/2002 SN /30/2000 SN /30/1996 SN /30/2002 SN Invalid input date SN Invalid input date SN Invalid input date SN Invalid input date SN Invalid input date SN Invalid input date SN /15/2000 SN /15/1996 SN /15/2002 SN /30/2000 SN /30/1996 SN /30/2002 SN /31/2000 SN /31/1996 SN /31/2002 SN /1/2000 SN /1/1996 SN /1/2002 SN /15/2000 SN /15/1996 SN /15/2002 SN Invalid input date SN /1/1996 SN Invalid input date SN Invalid input date SN Invalid input date SN Invalid input date SN Invalid input date

11 SN Invalid input date SN Invalid input date The move from weak to strong, whether with normal or robust classes, always makes the presumption of independence, and this is reflected in the cross-product of the equivalence classes. 3 month classes 4 day classes 3 year classes = 36 strong normal equivalence test cases. 5. a) Illustrate the scenario with the help of sample decision table where the decision table is Redundant and Inconsistent (i.e. Non-deterministic) (04 Marks) Answer: Decision table be concluded as redundant - if it has two identical rules i.e same action entries in two or more rules for different or identical condition entries as shown: In the table shown above action entries in rule 9 is identical to rule 1 to 4. Decision table be concluded as inconsistent - if actions in redundant rule are not identical (different) to the corresponding part of decision table as shown:

12 In the table shown above, if a transaction in which c1 is true and both c2 and c3 are false then both rules 4 and 9 apply. Two observations can be made: Answer: - rules 4 and 9 are inconsistent. - the decision table is nondeterministic. b) Explain in detail the concept of Rule Count considering Refined Decision Table for Triangle Program to indicate irrelevant don t care entries present in the decision table. (06 Marks) For limited entry decision tables, if n conditions exists, there must be 2^n rules. When don t care entries really indicate that the condition is irrelevant, we can develop a rule count as follows: rules in which no don t care entries occur count as one rule, and each don t care entry in a rule doubles the count of that rule as shown below: The sum of the rule count= 2^6=64.

13 6. Create a decision table for NextDate Function by identifying appropriate Equivalence classes as conditions and determine actions for generating all possible test cases by considering decision table with 22 Rules. Finally tabulate all 22 test cases for NextDate Function (10 Marks) Answer: M1= {month : month has 30 days} M2= {month : month has 31 days} M3= {month : month is february} M4:{month:month is December} D1= {day : 1<=day<=28} D2= {day : day=29} D3= {day : day=30} D4= {day : day=31} Y1= {year : year=2000} Y2= {year : year is a non-century leap year} Y3= {year : year is a common year

14 TEST CASE TEMPLATE Test Case Id Description Input Data Expected Output Actual Output Status (PASS / FAIL ) ********************* ALL THE VERY BEST *********************