软件测试技术(二)

一. 代码

在课本提供的代码基础上有所修改

package homework;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) { 
        System.out.println("请输入任意自然数");
        Scanner sc = new Scanner(System.in); 
        int n = sc.nextInt();

        printPrimes(n);
    }

    // Finds and prints n prime integers
    private 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[10]; // The list of primes.
        
        // 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; i++ ) {
                // for each previous prime.
                if(isDvisible(primes[i], curPrime)) {
                    // Found a divisor, curPrime is not prime.
                    isPrime = false;
                    break;
                }
            }
            if(isPrime) {
                // save it!
                primes[numPrimes] = curPrime;
                numPrimes++;
            }
        }
        
        // print all the primes out
        for(int i = 0; i < numPrimes; i++) {
            System.out.println("Prime: " + primes[i] );
        }
    }
    
    private static boolean isDvisible(int a, int b) {
        if(b % a == 0) {
            return true;
        } else {
            return false;
        }
    }
}

实现效果

二. 解题

(a) Draw the control flow graph for the printPrime() method.

(b) Consider test cases ti = (n = 3) and t2 = ( n = 5). Although these tour the same prime paths in printPrime(), they don't necessarily find the same faults. Design a simple fault that t2 would be more likely to discover than t1 would.

将MAXPRIMES的值设为4

(c) For printPrime(), find a test case such that the corresponding test path visits the edge that connects the beginning of the while statement to the for statement without going through the body of the while loop.

将n的值设为1

(d) Enumerate the test requirements for node coverage, edge coverage,and prime path coverage for the path for printPrimes().

点覆盖  {1，2，3，4，5，6，7，8，9，10，11，12，13}

边覆盖  {(1,2)，(1,10)，(2,3)，(3,4)，(4,5)，(4,7)，(5,6)，(5,7)，(6,4)，(7,8)，(7,9)，(8,9)，(9,2)，(10,11)，(10,13)，(11,12)，(12,10)}

主路径覆盖  {(1,2,3,4,5,6)，(1,2,3,4,5,7,8,9)，(1,2,3,4,5,7,9)，(1,2,3,4,7,8,9)，(1,2,3,4,7,9)，(1,10,11,12)，(1,10,13)，(4,5,6,4)，(10,11,12,10)}

 

三. 测试

代码如下

package homework;

import static org.junit.Assert.*;
import org.junit.Test;

public class MainTest {

    @Test
    public void testprintPrimes() {
        Main.printPrimes(5);
    }

}

 

效果如下