软件测试学习（4） printPrimes()

根据printPrimes()代码复习路径覆盖的知识。相关代码如下：

/*******************************************************
     * 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

（a）为printPrimes()画控制流图。

（b）设计一个简单的错误，使得t2（n=5）比t1（n=3）更容易发现。

较容易发生的为数组越界错误。当MAXPRIMES为4时，t2会越界。

（c）找到一个测试用例，使得相应的测试路径访问连接while语句开始到for语句的边，而不通过while循环体。

当n=1时，即可满足要求。

（d）要求找出点覆盖、边覆盖和主路径覆盖的所有TR（测试需求）

1）点覆盖：{1,2,3,4,5,6,7,8,9,10,11,12,13}

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

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

最后，设计主路径测试覆盖的用例。以三角形为例：

package triangle;

public class triangle {
    private int side1;
    private int side2;
    private int side3;

    public triangle()
    {
        this(1,1,1);
    }

    public triangle(int a, int b, int c) {
        this.side1 = a;
        this.side2 = b;
        this.side3 = c;
    }

    public String getType(int side1,int side2,int side3) throws Exception{
        if(side1 < 1 || side1 > 100 || side2 < 1 || side2 > 100 || side3 < 1 || side3 > 100)
            return "边取值超出范围" ;
        if(side1 + side2 <= side3 || side1 + side3 <= side2 ||side2 + side3 <= side1)
            throw new Exception("不构成三角形");
        if(side1 == side2 && side2 == side3)
            return "等边三角形";
        else if((side1 == side2 || side1 == side3 || side2 == side3)&&(IsRtTriangle(side1,side2,side3)))
            return "等腰直角三角形" ;
        else if(side1 == side2 || side1 == side3 || side2 == side3)
            return "等腰三角形";
        else if(IsRtTriangle(side1,side2,side3))
            return "直角三角形";
        else
            return "一般三角形";

        } 

    public boolean IsRtTriangle(int a,int b,int c){
        int a1 = a * a;
        int b1 = b * b;
        int c1 = c * c;
        if(a1 + b1 == c1 || a1 + c1 == b1 || b1 + c1 == a1)
            return true;
        return false;
    }

    public static void main(String[] args){
        triangle tr = new triangle (3,4,5);
        try
        {
            System.out.println(tr.getType(3,4,5));
        }catch(Exception e)
        {
            e.printStackTrace();
        }
    }
    }

@Parameters
    public static Collection<Object[]>getData(){
        return Arrays.asList(new Object[][]{
                {1,2,-1,false,"边取值超出范围"},
                {99,99,101,false,"边取值超出范围"},
                {3,2,2,false,"等腰三角形"},
                {2,2,2,false,"等边三角形"},
                {3,4,5,true,"直角三角形"},
                {3,4,2,false,"一般三角形"},
        });
    }
    @Test
    public void testType() throws Exception
    {

        assertEquals(this.expType,tr.getType(input1,input2,input3));
    }

即可实现代码的主路径全覆盖。