软件测试学习（4）

    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

a）画出数据流图。

b)测试用例t1=(n=3)和t2=(n=5),设计一个t2能发现但是t1不能发现的错误。

　　数组越界问题。

c）找到一个不经过while循环的测试用例。

　　n=1；

d）找出点覆盖、边覆盖和主路径覆盖的所有测试需求。

　　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),(3,4),(4,5),(5,6),(5,9),(6,7),(6,8),(7,5),(8,9),(9,10),(9,11),(10,11),(11,2),(2,12),(12,13),(13,14),(13,16),(14,15),(15,13)}

　　主路径覆盖：

{(1,2,3,4,5,6,7),(1,2,3,4,5,6,8,9,11),(1,2,3,4,5,6,8,9,10,11),(1,2,3,4,5,9,11),(1,2,3,4,5,9,10,11),(1,2,12,13,16),(1,2,12,13,14,15),

(2,3,4,5,9,11,2),(2,3,4,5,9,10,11,2),(2,3,4,5,6,8,9,11,2),(2,3,4,5,6,8,9,10,11,2),

(3,4,5,9,11,2,3),(3,4,5,9,10,11,2,3),(3,4,5,6,8,9,11,2,3),(3,4,5,6,8,9,10,11,2,3),(3,4,5,9,11,2,12,13,16),(3,4,5,9,11,2,12,13,14,15),(3,4,5,9,10,11,2,12,13,16),(3,4,5,9,10,11,2,12,13,14,15),(3,4,5,6,8,9,11,2,12,13,16),(3,4,5,6,8,9,11,2,13,14,15),(3,4,5,6,8,9,10,11,2,12,13,16),(3,4,5,6,8,9,10,11,2,12,13,14,15),

(4,5,9,11,2,3,4),(4,5,9,10,11,2,3,4),(4,5,6,8,9,11,2,3,4),(4,5,6,8,9,10,11,2,3,4),

(5,6,7,5),(5,9,11,2,3,4,5),(5,9,10,11,2,3,4,5),(5,6,8,9,11,2,3,4,5),(5,6,8,9,10,11,2,3,4,5),

(6,7,5,6),(6,8,9,11,2,3,4,5,6),(6,8,9,10,11,2,3,4,5,6),(6,7,5,9,11,2,12,13,16),(6,7,5,9,11,2,12,13,14,15),(6,7,5,9,10,11,2,12,13,16),(6,7,5,9,10,11,2,12,13,14,15),(6,7,5,9,11,2,3,4,5,6),(6,7,5,9,10,11,2,3,4,5,6),

(7,5,6,7),(7,5,6,8,9,11,2,3,4),(7,5,6,8,9,10,11,2,3,4),(7,5,6,8,9,11,2,12,13,16),(7,5,6,8,9,11,2,12,13,14,15),(7,5,6,8,9,10,11,2,12,13,16),(7,5,6,8,9,10,11,2,12,13,14,15),

(8,9,11,2,3,4,5,6,8),(8,9,10,11,2,3,4,5,6,8),(8,9,11,2,3,4,5,6,7),(8,9,10,11,2,3,4,5,6,7),

(9,11,2,3,4,5,9),(9,10,11,2,3,4,5,9),(9,11,2,3,4,5,6,8,9),(9,10,11,2,3,4,5,6,8,9),

(10,11,2,3,4,5,9,10),(10,11,2,3,4,5,6,8,9,10),

(11,2,3,4,5,9,11),(11,2,3,4,5,9,10,11),(11,2,3,4,5,6,8,9,11),(11,2,3,4,5,6,8,9,10,11)

(13,14,15,13),

(14,15,13,14),(14,15,13,16),

(15,13,14,15)}

Junit进行主路径覆盖测试

public class Statistics {

    /**
     *
     * @param numbers
     * @return the length of the array
     */
    public int calLength(int[] numbers) {
        int length = numbers.length;

        return length;
    }

    /**
     *
     * @param numbers
     * @return the mean value of the array
     */

    public double calMean(int[] numbers) {
        int length = calLength(numbers);

        double sum;
        sum = 0.0;
        for (int i = 0; i < length; i++) {
            sum += numbers[i];
        }
        double mean = sum / (double) length;

        return mean;
    }

    /**
     *
     * @param numbers
     * @return the var value of the array
     */
    public double calVar(int[] numbers) {
        int length = calLength(numbers);
        double mean = calMean(numbers);

        double varsum = 0.0;
        for (int i = 0; i < length; i++) {
            varsum = varsum + ((numbers[i] - mean) * (numbers[i] - mean));
        }
        double var = varsum / (length - 1.0);

        return var;
    }

}

import static org.junit.Assert.*;

import org.junit.Before;
import org.junit.Test;

public class StatisticsTest {
    private Statistics statistics;

    @Before
    public void setUp() throws Exception {
        statistics = new Statistics();
    }

    @Test
    public void test() {
        //fail("Not yet implemented");
        int a[] = {1,1,1,1,1,1} ;
        assertEquals(0.0,statistics.calVar(a),0.0001);
    }

}