EvaluationExerciseTest.java

package com.exercises.test;

import java.util.Random;

import com.exercises.main.EvaluationExercise;

public class EvaluationExerciseTest {

	/**
	 * Unit testing of a random number of cases.
	 * When a case is incorrect, the testing is interrupted. It continues, otherwise.
	 * The program displays number of cases to be tested.
	 * The program also displays the original array, its rotated version, and the number of rotation,
	 * as well as the test unit verdict (OK, KO).
	 * @param args
	 */
	public static void main(String[] args) {
		EvaluationExercise exercise;
		int cases = Math.abs(new Random().nextInt()) % EvaluationExercise.MAX_SIZE;
		System.out.println(cases + " arrays to be tested.");
		System.out.println();
		do {
			exercise = new EvaluationExercise(EvaluationExerciseTest.generateRandomArray());
			
			int n = Math.abs(new Random().nextInt()) % exercise.getArray().length;
			/*
			 * Making a copy of the original array.
			 */
			int[] arrayCopy = exercise.getArray().clone();
			/*
			* Rotating.
			*/
			exercise.rotate(n); 
			/*
			 * Test Unit of the array, to verify the correctness of the result.
			 */
			assert EvaluationExerciseTest.testUnitArrayRotation(n, exercise.getArray(), arrayCopy);
			cases --;
			
		} while (cases > 0);
	}

	
	/**
	 * Unit testing of the array.
	 * The property to be tested is the new position of an element: Was it "shifted" n times as expected.
	 * 
	 * @param rotationNumber
	 * @param array
	 * @param arrayCopy
	 * @return
	 */
	public static boolean testUnitArrayRotation(int rotationNumber, int[] array, int[] arrayCopy) {
		System.out.println("Original array: ");new EvaluationExercise(arrayCopy).displayArray();
		System.out.println();
		System.out.println("Rotated array: ");new EvaluationExercise(array).displayArray();
		System.out.println();
		System.out.println("Number of rotations: " + rotationNumber);
		for (int i = 0; i < array.length; i++) {
			if ( array[ ( i + rotationNumber ) % array.length ] != arrayCopy[ i ]) {
				System.out.println("Test KO");
				return false;
			}
		}
		System.out.println("Test OK");
		System.out.println();
		return true;
	}
	/**
	 * This function generates a random array of integers (random size, random positive elements).
	 * @return
	 */
	public static int[] generateRandomArray() {
		Random r = new Random();
		
		int size = Math.abs(r.nextInt()) % EvaluationExercise.MAX_SIZE + 1;
		int[] array = new int[size];
		for (int i = 0; i < size; i ++) {
			array[i] = Math.abs(r.nextInt()) % EvaluationExercise.MAX_SIZE;
		}
		return array;
	}

}