这周我们主要学习了路径覆盖的相关知识,首先来看一下这周的作业题
/******************************************************* * Finds and prints n prime integers * Jeff Offutt, Spring 2003 ******************************************************/ public static void printPrimes (int n) { int curPrime; // Value currently considered for primeness int numPrimes; // Number of primes found so far. boolean isPrime; // Is curPrime prime? int [] primes = new int [MAXPRIMES]; // The list of prime numbers. // Initialize 2 into the list of primes. primes [0] = 2; numPrimes = 1; curPrime = 2; while (numPrimes < n) { curPrime++; // next number to consider ... isPrime = true; for (int i = 0; i <= numPrimes-1; i++) { // for each previous prime. if (curPrime%primes[i]==0) { // Found a divisor, curPrime is not prime. isPrime = false; break; // out of loop through primes. } } if (isPrime) { // save it! primes[numPrimes] = curPrime; numPrimes++; } } // End while // Print all the primes out. for (int i = 0; i <= numPrimes-1; i++) { System.out.println ("Prime: " + primes[i]); } } // end printPrimes
第一问是画控制流图,用网上的相关软件可以很容易的画出来
第二问是设计一个t2=(n=5)能发现但t1=(n=3)不能发现的错误
一个最直观的错误就是数组越界,n取的值越大,数组越界就越有可能发生
第三问是寻找一组不经过while循环的测试用例,n=1的时候就可以满足要求
第四问要求找出点覆盖、边覆盖和主路径覆盖的所有TR(测试需求)
点覆盖:{1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16}
边覆盖:{(1,2),(2,3),(2,12),(3,4),(4,5),(5,6),(6,7),(6,8),(7,5),(8,9),(5,9),(9,10),(9,11),(10,11),(11,2),(12,13),(13,14),(14,15),(15,13),(13,16)}
主路径覆盖:{(1,2,3,4,5,6,7),
(1,2,3,4,5,6,8,9,10,11),
(1,2,3,4,5,6,8,9,11),
(1,2,3,4,5,9,10,11),
(1,2,3,4,5,9,11),
(1,2,12,13,14,15),
(1,2,12,16),
(3,4,5,6,8,9,10,11,2,12,13,14,15),
(3,4,5,6,8,9,11,2,12,13,14,15),
(3,4,5,6,8,9,10,11,2,12,13,16),
(3,4,5,6,8,9,11,2,12,13,16),
(3,4,5,9,10,11,2,12,13,14,15),
(3,4,5,9,11,2,12,13,14,15),
(3,4,5,9,10,11,2,12,13,16),
(3,4,5,9,11,2,12,13,16),
(6,7,5,9,10,11,2,12,13,14,15),
(6,7,5,9,11,2,12,13,14,15),
(6,7,5,9,10,11,2,12,13,16),
(6,7,5,9,11,2,12,13,16),
(14,15,13,16),
(13,14,15,13),
(5,6,7,5),
(2,3,4,5,6,8,9,10,11,2),
(2,3,4,5,6,8,9,11,2),
(2,3,4,5,9,10,11,2),
(2,3,4,5,9,11,2),
}
最后,对任意程序设计主路径覆盖的测试用例,以上次的判断三角形的形状的程序为例
package cn.tju.st; public class Triangle { public int a; public int b; public int c; public Triangle(int a,int b,int c) { this.a=a; this.b=b; this.c=c; } public String judge() { if(a==b&&b==c) return "equilateral"; else if(a==b||b==c||c==a) return "isosceles"; else { return "scalene"; } } }
package cn.tju.st; import static org.junit.Assert.*; import org.junit.After; import org.junit.Before; import org.junit.Test; public class TestTriangle { Triangle tri =null; @Before public void setUp() throws Exception { //System.out.println("This is before test"); } @After public void tearDown() throws Exception { System.out.println("This is after test"); } @Test public void test() { tri = new Triangle(3,3,3); assertEquals("equilateral",tri.judge()); tri = new Triangle(2,3,3); assertEquals("isosceles",tri.judge()); tri = new Triangle(3,4,5); assertEquals("scalene",tri.judge()); } }
三组测试用例(3,3,3),(2,3,3),(3,4,5)即可完成主路径覆盖