Assignment7
- 构造下述三角形问题的弱健壮的等价类测试用例。
- 三角形问题：输入三个不超过100的正整数作为三角形的三条边，判断三角形是等边三角形、等腰不等边三角形、完全不等边三角形还是不能构成三角形。
Answer
- 等价类的划分
- 一个输入等价类是指程序输入域的某个子集，在该子集中，各个输入数据对于揭露程序中的错误是等效的。测试某一个等价类的代表值就等同于对这个等价类的其他值的测试。
- 等价类的划分有两种：
- 有效等价类：对于程序规格说明来说是合理的、有意义的输入数据构成的集合。
- 无效等价类：对于程序规格说明来说是不合理的、无意义的输入数据构成的集合。
第一步：划分等价类
- R1 = {<*a*,*b*,*c*>: the triangle with sides a, b, and c is equilateral}
- R2 = {<*a*,*b*,*c*>: the triangle with sides a, b, and c is isosceles}
- R3 = {<*a*,*b*,*c*>: the triangle with sides a, b, and c is scalene}
- R4 = {<*a*,*b*,*c*>: sides a, b, and c do not form a triangle}
第二步：为每个等价类构造测试用例
| Test Case |
a |
b |
c |
Expected Output |
| WN1 |
3 |
3 |
3 |
Equilateral |
| WN2 |
3 |
3 |
4 |
Isosceles |
| WN3 |
3 |
4 |
5 |
Scalene |
| WN4 |
1 |
1 |
2 |
Not a triangle |
第三步：构造弱健壮性等价类测试用例
因为a,b,c的非法值，所以要增加弱健壮等价类测试用例
| Test Case |
a |
b |
c |
Expected Output |
| WR1 |
-1 |
3 |
3 |
value of a is out of range |
| WR2 |
3 |
-1 |
3 |
value of b is out of range |
| WR3 |
3 |
3 |
-1 |
value of c is out of range |
| WR4 |
110 |
98 |
99 |
value of a is out of range |
| WR5 |
98 |
110 |
99 |
value of b is out of range |
| WR6 |
98 |
99 |
110 |
value of c is out of range |
| WR7 |
3.5 |
3 |
4 |
value of a is not type int |
| WR8 |
3 |
3.5 |
4 |
value of b is not type int |
| WR9 |
3 |
4 |
3.5 |
value of c is not type int |
Reference
- http://www.testingeducation.org/conference/wtst3_collard4.pdf
- Lec.16 by Prof. Guoyang Cai
