软件测试：3.Exercise Section 2.3

/************************************************************
 * Finds and prints n prime integers
 * Jeff Offutt, Spring 2003
*************************************************************/
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[MAXPRIMES];    // 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++;
        }
    }// End while

    // Print all the primes out
    for(int i = 0; i < numPrimes; i++) {
        System.out.println("Prime: " + primes[i] );

    }

}// End printPrimes.

　　Questions:

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

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

　　(c) For printPrimes(), 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.

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

　　(e) List test paths that achieve node coverage but not edge coverage ont the graph.

　　(f) List test paths that achieve edge coverage but not prime path coverage on the graph.

　　Answers:

　　(a) Draw the control flow graph for the printPrimes() method:

　　(b) 将MAXPRIMES设置为4时，t2会发生数组越界错误，但t1不会发生错误。

　　(d) Node Coverage

　　　　TR={1,2,3,4,5,6,7,8,9,10,11,12,13,14}

　　　Edge Coverage

　　　　TR={(1,2), (2,3), (2,10), (3,4), (4,5), (5,6), (5,8), (6,5), (6,7), (7,8), (8,2),(8,9), (9,2), (10,11), (11,12), (11,14), (12,13), (13,11)}

　　　Prime Path Coverage

　　　　Test Paths:　[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],
　　　　　　　　　　[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],
　　　　　　　　　　[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],
　　　　　　　　　　[5,6,7,5],
　　　　　　　　　　[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],
　　　　　　　　　　[13,14,15,13],
　　　　　　　　　　[14,15,13,16]