PrimeTest

gistfile1.java

import AlgoTools.IO;
import java.util.Scanner;
import java.io.*;

public class PrimeTest {
    private static String m_program;
    private static String m_yesString;
    private static String m_noString;

    public static void main(String[] args) throws Exception {
        // Check command line parameter
        if(args.length < 3) {
            IO.println("To few arguments! Usage:");
            IO.println("java PrimeTest program yesString noString");
            IO.println("");
            IO.println("program:  \tProgram to test");
            IO.println("yesString:\tString that is found in the output of your "
                + "program if the input is a prime");
            IO.println("noString: \tString that is found in the output of your "
                + "program if the input is NOT a prime");
            return;
        }
        m_program = args[0];
        m_yesString = args[1];
        m_noString = args[2];

        IO.println("Will test application '" + m_program
            + "' with yesString '" + m_yesString
            + "' and noString '" + m_noString + "'");
        IO.println("----------------------------");
        IO.println();



        for(int i = 1; i < 9001; ++i) {
            if(i % 100 == 0) {
                IO.println(">>> Testing " + i);
            }
            if(testNumber(i)) {
                break;
            }
            
        }
    }

    private static boolean testNumber(int number) throws Exception {
        ProcessBuilder builder = new ProcessBuilder("java", m_program);
        Process process = builder.start();

        OutputStream stdin = process.getOutputStream();

        BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(stdin));

        writer.write("" + number);
        writer.flush();
        writer.close();
        
        InputStream stdout = process.getInputStream();
        BufferedReader reader = new BufferedReader(new InputStreamReader(stdout));

        Scanner scanner = new Scanner(stdout);
        String all = "";
        while (scanner.hasNextLine()) {
            all += scanner.nextLine();
        }

        boolean progSays = true;
        if(all.indexOf(m_yesString) == -1) {
            // shouldn't be a prime
            if(all.indexOf(m_noString) == -1) {
                IO.println("yesString and noString was found in output! "
                    + "Fix that!");
                System.exit(-1);
            }
            progSays = false;
        }
        if(all.indexOf(m_noString) == -1) {
            IO.println("Neither yesString nor noString was found in output! "
                + "Fix that!");
            System.exit(-1);
        }

        if(progSays != isPrime(number)) {
            IO.println("Error detected! Number: " + number);
            IO.println("ProgOutput -> ");
            IO.println(all);
            return false;
        }
        return true;
    }

    private static boolean isPrime(int number) {
        // early return Mr. Haldenwang :*
        if(number == 2) {
            return true;
        }
        if(number == 1 || number % 2 == 0) {
            return false;
        }

        for(int i = 3; i <= Math.sqrt(number); ++i) {
            if(number % i == 0) {
                return false;
            }
        }
        return true;
    }


}