software testing

without making any changes to the java classes provided below, come up with some junit test cases to test the code.

MyCustomString

public class MyCustomString implements MyCustomStringInterface { private String string;

@Override public String getString() { return string; }

@Override public void setString(String string) { this.string = string; }

@Override public int countNumbers() { StringBuffer tmpString = new StringBuffer(); int count=0; boolean inNumber=false; //avoid null pointer exception! if(string==null || string.isEmpty()) return 0; for (int i = 0; i < string.length(); i++) { char ch = string.charAt(i); if (Character.isDigit(ch)) { if (!inNumber) { count++; inNumber = true; } } else { if (inNumber) { inNumber = false; } } } return count; }

@Override public String reverseNCharacters(int n, boolean padded) { if (string == null) { throw new NullPointerException(); } if (n <= 0) { throw new IllegalArgumentException(); } StringBuffer tmpString = new StringBuffer(); StringBuffer resultString = new StringBuffer(); StringBuffer currString = new StringBuffer(string);

int i; for (i = 0; i + n < currString.length(); i+=n) { tmpString = tmpString.append(new StringBuffer(currString.substring(i,i+n)).reverse()); } if (padded) { for (int x = n - (currString.length() - i); x > 0; x--) currString.append('X'); } tmpString = tmpString.append(new StringBuffer(currString.substring(i)).reverse());

return tmpString.toString(); }

@Override public void convertDigitsToNamesInSubstring(int startPosition, int endPosition) { if (string == null) { throw new NullPointerException(); } if ((startPosition > endPosition)) { throw new IllegalArgumentException(); }

if (endPosition > string.length() || (startPosition < 1)){ throw new MyIndexOutOfBoundsException(); } StringBuffer tmpString = new StringBuffer(); String tmpDigit = new String(); boolean look_back = false; for (int i = 0; i < string.length(); i++) { char ch = string.charAt(i); if ((i < startPosition - 1) || (i > endPosition - 1)) { if(look_back) { look_back = false; } tmpString.append(ch); continue; } else { if (Character.isDigit(ch)) { switch (ch) { case '0': tmpDigit = "Zero"; break; case '1': tmpDigit = "One"; break; case '2': tmpDigit = "Two"; break; case '3': tmpDigit = "Three"; break; case '4': tmpDigit = "Four"; break; case '5': tmpDigit = "Five"; break; case '6': tmpDigit = "Six"; break; case '7': tmpDigit = "Seven"; break; case '8': tmpDigit = "Eight"; break; case '9': tmpDigit = "Nine"; break; } if(look_back) tmpString.append(tmpDigit.toLowerCase()); else tmpString.append(tmpDigit); look_back = true; } else { if(look_back){ look_back = false;} tmpString.append(ch);

} }

MyCustomStringInterface

} string = tmpString.toString(); } }

public interface MyCustomStringInterface {

String getString();

void setString(String string);

int countNumbers();

String reverseNCharacters(int n, boolean padded);

void convertDigitsToNamesInSubstring(int startPosition, int endPosition); } MyIndexOutOfBoundsException

public class MyIndexOutOfBoundsException extends RuntimeException { private static final long serialVersionUID = 8226094121089030034L;

public MyIndexOutOfBoundsException(String message) { super(message); }

public MyIndexOutOfBoundsException() { super(); } }