import java.util.List;
import java.util.ArrayList;
import java.util.Iterator;
import java.lang.reflect.*;

public class UnitTester

{	/** testClass is the class that contains the testcases	*/
	private Class testClass;
	
	/** testMethods is an vector of the methods that contain
	* consists the tests to be executed	*/
	private List<Method> testMethods;
	
	/** test object is an instance of testClass.	*/
	private Object testObject;


	/** Set the class to be testet. The className must be a name in classpath.	*/
	private void setClass(String className)
		throws ClassNotFoundException, InstantiationException,
					IllegalAccessException {
		testClass = Class.forName(className);
		testObject = testClass.newInstance();
	}

	/**get the methods in testClass that take no arguments, and have
	* a methodName that starts with "test".	*/
	private void getMethods(){
		testMethods = new ArrayList<Method>();
		try{
			Method[] allMethods = testClass.getMethods();
			for (Method m : allMethods){
				if ( m.getName().startsWith("test")){		
					testMethods.add(m);
				}
			}
		}catch(SecurityException whatWasThat){}
	}

	/** execute all the testMethods, and report the result	*/
	private String performTests(){
		String result = "Test of " + testClass.getName() + "\n";
		for ( Method m : testMethods ){
			try{
				m.invoke(testObject, new Object[0]);
				result += m.getName() + " OK\n";
			}catch(InvocationTargetException uups){
				Throwable target = uups.getTargetException();
				if ( target instanceof TestClass.CheckFailure)
					result += m.getName() +" Check failed: "
						+ ((TestClass.CheckFailure)target).msg + "\n";
				else
					result += m.getName() + " Exception: " + target.toString() + "\n";
			}
			catch(Exception oops){result += oops;}
		}
		return result;
	}

	public static String testTheClass(String name){
		try{
			UnitTester ut = new UnitTester();
			ut.setClass(name);
			ut.getMethods();
			return ut.performTests();
		}catch(Exception uups){
			return "Could not find class " + name + "\n" + uups;
		}
	}

}