软件测试（三）

Using the following method printPrimes() for questions a-d below

/******************************************************* 
     * 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) 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 ptinrPrimes(), they do not necessarily find the same faults. Design a simple fault that t2 would be more likely to discover than t1 would.

When MAXPRIMES = 3 or 4, t2=(n=5) will overflow and t1=(n=3) won't.

 

(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 withtout going through the body of the while loop.

When n = 1, it will run through edge (2, 12), which statify the requirement.

 

(d) Enumerate the test requirements for node coverage, edge coverage, amd prime path coverage for the graph fpr printPrime().

Node Coverage 

TR = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16};

Edge Coverage

TR = {(1,2), (2,3), (2,12), (3,4), (4,5), (5,6), (5,9), (6,7), (6,8), (7,5), (8,9)

　　　(9,10), (9,11), (10,11), (11,2), (12,13), (13,14), (13,16), (14,15), (15,13)};

 Prime Path Coverage

 

TR = {[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],

[1,2,12,13,14,15], [1,2,12,13,16],

[2,3,4,5,6,8,9,10,11,2], [3,4,5,6,8,9,10,11,2,3], [4,5,6,8,9,10,11,2,3,4], [5,6,8,9,10,11,2,3,4,5],

[6,8,9,10,11,2,3,4,5,6], [8,9,10,11,2,3,4,5,6,8], [9,10,11,2,3,4,5,6,8,9], [10,11,2,3,4,5,6,8,9,10],

[11,2,3,4,5,6,8,9,10,11],

[2,3,4,5,6,8,9,11,2], [3,4,5,6,8,9,11,2,3], [4,5,6,8,9,11,2,3,4], [5,6,8,9,11,2,3,4,5],

[6,8,9,11,2,3,4,5,6], [8,9,11,2,3,4,5,6,8], [9,11,2,3,4,5,6,8,9], [11,2,3,4,5,6,8,9,11],

[2,3,4,5,9,10,11,2], [3,4,5,9,10,11,2,3], [4,5,9,10,11,2,3,4], [5,9,10,11,2,3,4,5],

[9,10,11,2,3,4,5,9], [10,11,2,3,4,5,9,10], [11,2,3,4,5,9,10,11],

[2,3,4,5,9,11,2], [3,4,5,9,11,2,3], [4,5,9,11,2,3,4], [5,9,11,2,3,4,5], [9,11,2,3,4,5,9],

[11,2,3,4,5,9,11],

[13,14,15,13], [14,15,13,14], [15,13,14,15],

[5,6,7,5], [6,7,5,6], [7,5,6,7],

[3,4,5,9,11,2,12,13,16], [3,4,5,9,10,11,2,12,13,16], [3,4,5,6,8,9,11,2,12,13,16],

[3,4,5,6,8,9,10,11,2,12,13,16],

[3,4,5,9,11,2,12,13,14,15], [3,4,5,9,10,11,2,12,13,14,15], [3,4,5,6,8,9,11,2,12,13,14,15],

[3,4,5,6,8,9,10,11,2,12,13,14,15],

[6,7,5,9,11,2,3,4], [6,7,5,9,10,11,2,3,4], [6,7,5,9,11,2,12,13,14,15], [6,7,5,9,10,11,2,12,13,14,15],

[6,7,5,9,11,2,12,13,16], [6,7,5,9,10,11,2,12,13,16],

[7,5,6,8,9,11,2,3,4], [7,5,6,8,9,10,11,2,3,4], [7,5,6,8,9,11,2,12,13,14,15],

[7,5,6,8,9,10,11,2,12,13,14,15], [7,5,6,8,9,11,2,12,13,16], [7,5,6,8,9,10,11,2,12,13,16],

[8,9,11,2,3,4,5,6,7], [8,9,10,11,2,3,4,5,6,7],

[14,15,13,16]  };

 

Prime Path Coverage:

package Prime;

import static org.junit.Assert.*;
import java.util.Collection;
import org.junit.Test;
import org.junit.Before;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;
import java.util.Arrays;

import Prime.PrintPrime;

@RunWith(Parameterized.class)
public class PrintPrimesTest {
    private String expected = "";
    private int n;
    private PrintPrime printPrimes;
    
    public PrintPrimesTest(int num, String expec){
        n = num;
        expected = expec;
    }
    
    @Before
    public void setUp(){
        printPrimes = new PrintPrime();
    }
    
    @Test
    public void test(){
        assertEquals(this.expected, printPrimes.printPrimes(this.n));
    }
    
    @Parameters
    public static Collection<Object[]> getData(){
        return Arrays.asList(new Object[][] {
            {2, "2 3 "},
            {3, "2 3 5 "}
        });
    }
}

But first we should let function printPrimes (int n) return the result for testing.

Right click the PrintPrimesTest.java and -- Coverage As -- JUnit Test.

 If n =2, it only coverages 97.7%

While n = 3, it coverages 100%.