code_for_testing_lists.java

package com.utils;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.junit.MockitoJUnitRunner;

import java.util.*;
import java.util.stream.Collectors;


@RunWith(MockitoJUnitRunner.class)
public class ListOps {

	@Test
	public void testAsList() {
		System.out.println("### TESTING asList ###");

		List<Character> asList = Arrays.asList('A', 'V');
		List<Character> asList2 = Arrays.asList('A', 'V');
		doListOps(asList, asList2);
	}

	@Test
	public void testListOf() {
		System.out.println("### TESTING List.Of ###");
		List<Character> asList = List.of('A', 'V');
		List<Character> asList2 = List.of('A', 'V');
		doListOps(asList, asList2);
	}

	@Test
	public void testSingletonList() {
		System.out.println("### TESTING singletonList ###");
		List<Character> asList = Collections.singletonList('A');
		List<Character> asList2 = Collections.singletonList('A');
		doListOps(asList, asList2);
	}

	@Test
	public void testArrayList() {
		System.out.println("### TESTING singletonList ###");
		List<Character> asList = new ArrayList<>(Arrays.asList('A', 'V'));
		List<Character> asList2 = new ArrayList<>(Arrays.asList('A', 'V'));
		doListOps(asList, asList2);
	}

	@Test
	public void testUnmodifiableList() {
		System.out.println("### TESTING unmodifiableList ###");
		List<Character> asList = Collections.unmodifiableList(List.of('A', 'V'));
		List<Character> asList2 = Collections.unmodifiableList(List.of('A', 'V'));
		doListOps(asList, asList2);
	}

	public void doListOps(List<Character> list, List<Character> list2) {
		UnsupportedOperationException exc = null;

		try {
			System.out.println("add operation for list");

			list.add('Y');
		}
		catch (UnsupportedOperationException e) {
			exc = e;
		}


		if (exc == null) {
			System.out.println("Exception not thrown for add");
		} else {
			System.out.println("Exception thrown for add " + exc);
		}
		printList(list);

		exc = null;
		System.out.println("========================");

		try {
			System.out.println("set operation for list");

			list.set(0, 'A');
		}
		catch (UnsupportedOperationException e) {
			exc = e;
		}

		if (exc == null) {
			System.out.println("Exception not thrown for set");
		} else {
			System.out.println("Exception thrown for set " + exc);
		}
		printList(list);

		exc = null;
		System.out.println("========================");

		try {
			System.out.println("addAll operation for list");

			list.addAll(0, list2);
		}
		catch (UnsupportedOperationException e) {
			exc = e;
		}

		if (exc == null) {
			System.out.println("Exception not thrown for addAll");
		}
		else {
			System.out.println("Exception thrown for addAll " + exc);
		}
		printList(list);

		exc = null;
		System.out.println("========================");

		try {
			System.out.println("remove operation for list");

			list.remove(0);
		}
		catch (UnsupportedOperationException e) {
			exc = e;
		}

		if (exc == null) {
			System.out.println("Exception not thrown for remove");
		}
		else {
			System.out.println("Exception thrown for remove " + exc);
		}
		printList(list);

		exc = null;
		System.out.println("========================");


		try {
			System.out.println("removeAll WITH FULL LIST operation for list");

			list.removeAll(list2);
		}
		catch (UnsupportedOperationException e) {
			exc = e;
		}

		if (exc == null) {
			System.out.println("Exception not thrown for removeAll WITH FULL LIST ");
		}
		else {
			System.out.println("Exception thrown for removeAll WITH FULL LIST " + exc);
		}
		printList(list);

		exc = null;
		System.out.println("========================");

		try {
			System.out.println("removeAll WITH EMPTY LIST operation for list");

			list.removeAll(Collections.emptyList());
		}
		catch (UnsupportedOperationException e) {
			exc = e;
		}

		if (exc == null) {
			System.out.println("Exception not thrown for removeAll");
		}
		else {
			System.out.println("Exception thrown for removeAll  WITH EMPTY LIST  " + exc);
		}
		printList(list);

		exc = null;
		System.out.println("========================");



		try {
			System.out.println("retainAll() WITH EMPTY LIST operation for list");

			list.retainAll(Collections.emptyList());
		}
		catch (UnsupportedOperationException e) {
			exc = e;
		}

		if (exc == null) {
			System.out.println("Exception not thrown for retainAll() WITH EMPTY LIST ");
		}
		else {
			System.out.println("Exception thrown for retainAll() WITH EMPTY LIST " + exc);
		}
		printList(list);

		exc = null;
		System.out.println("========================");

		try {
			System.out.println("retainAll WITH SAME LIST operation for list");

			list.retainAll(list2);
		}
		catch (UnsupportedOperationException e) {
			exc = e;
		}

		if (exc == null) {
			System.out.println("Exception not thrown for retainAll");
		}
		else {
			System.out.println("Exception thrown for retainAll  WITH EMPTY LIST  " + exc);
		}
		printList(list);

		exc = null;
		System.out.println("========================");

		try {
			System.out.println("replaceAll operation for list");

			list.replaceAll(Character::charValue);
		}
		catch (UnsupportedOperationException e) {
			exc = e;
		}

		if (exc == null) {
			System.out.println("Exception not thrown for replaceAll");
		}
		else {
			System.out.println("Exception thrown for replaceAll " + exc);
		}

		printList(list);

		exc = null;
		System.out.println("========================");

		try {
			System.out.println("sort operation for list");

			list.sort(Character::compareTo);
		}
		catch (UnsupportedOperationException e) {
			exc = e;
		}

		if (exc == null) {
			System.out.println("Exception not thrown for sort");
		}
		else {
			System.out.println("Exception thrown for sort " + exc);
		}

		exc = null;
		printList(list);
		System.out.println("========================");

		List<Character> tmp = list;

		try {
			System.out.println("clear operation for list");
			list.clear();
		}
		catch (UnsupportedOperationException e) {
			exc = e;
		}

		if (exc == null) {
			System.out.println("Exception not thrown for clear");
		}
		else {
			System.out.println("Exception thrown for clear " + exc);
		}

		list = tmp;
		printList(list);
		exc = null;
		System.out.println("========================");
	}

	private void printList(List<Character> list)
	{
		System.out.println("========================");
		System.out.println("PRINTING LIST");
		System.out.println(list.stream().map(Object::toString)
							   .collect(Collectors.joining(" ")));
		System.out.println("========================");
	}
}