Tutorial-6 To Generate Equivalence Class Test Cases-For the Triangle Problem

Posted in: Black Box Testing

Tutorial-6: To Generate Equivalence Class Test Cases-For the Triangle Problem

“The triangle program takes three integers, a, b and c as input. These are taken to be the sides of the triangle.

The output of the program can be either of: Equilateral Triangle, Isosceles Triangle, Scalene or “Not a Triangle”.

We can use these to identify output (range) equivalence classes as under:

01 = {<a, c=”” b,=””> : the triangle is equilateral}
</a,>

02 = {<a, c=”” b,=””> : the triangle is isosceles}
</a,>

03 = {<a, c=”” b,=””> : the triangle is scalene}
</a,>

04 = {<a, c=”” b,=””> : sides a, b and c do not form a triangle}</a,>

Objective of this Tutorial: To apply the four techniques of equivalence class partitioning one by one & generate appropriate test cases?

1) Weak Normal Equivalence Class: The four weak normal equivalence class test cases can be defined as under

Test Case ID	Side “a”	Side “b”	Side “c”	Expected Output
WN1	5	5	5	Equilateral Triangle
WN2	2	2	3	Isosceles Triangle
WN3	3	4	5	Scalene Triangle
WN4	4	1	2	Not a Triangle

2) Strong Normal Equivalence Class: Since no valid subintervals of variables a, b and c exist, so the strong normal equivalence class test cases are identical to the weak normal equivalence class test cases.

3) Weak Robust Equivalence Class: Considering the invalid values for a, b and c yields the following additional weak robust equivalence class test cases

Test Case ID	Side “a”	Side “b”	Side “c”	Expected Output
WR1	1	5	5	Invalid Value of a
WR2	5	-1	5	Invalid Value of b
WR3	5	5	-1	Invalid Value of c
WR4	201	5	5	Out of Range Value of a
WR5	5	201	5	Out of Range Value of a
WR6	5	5	201	Out of Range Value of a

4) Strong Robust Equivalence Class: Test Cases falling under this category are

Test Case ID	Side “a”	Side “b”	Side “c”	Expected Output
SR1	-1	5	5	Invalid Value of a
SR2	5	-1	5	Invalid Value of b
SR3	5	5	-1	Invalid Value of c
SR4	-1	-1	5	Invalid Value of a & b
SR5	5	-1	-1	Invalid Value of b & c
SR6	-1	5	-1	Invalid Value of a & c
SR7	-1	-1	-1	Invalid Value of a , b & c