package com.example;

import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.DisplayName;
import static org.junit.jupiter.api.Assertions.*;

public class MainTest {
    @Test
    @DisplayName("size() returns 0 for empty list")
    void testEmptyListSize() {
        LinkedList list = new LinkedList();
        assertEquals(0, list.size(), "size() should return 0 for an empty list");
    }

    @Test
    @DisplayName("size() returns correct count after adds")
    void testSizeAfterAdd() {
        LinkedList list = new LinkedList();
        list.add(1);
        list.add(2);
        list.add(3);
        assertEquals(3, list.size(), "size() should return 3 after adding 3 elements");
    }

    @Test
    @DisplayName("delete() removes head element and size updates")
    void testDeleteHead() {
        LinkedList list = new LinkedList();
        list.add(7);
        list.add(8);
        list.add(9);
        list.delete(0);
        assertEquals(2, list.size(), "size() should return 2 after deleting head");
        assertEquals(8, list.get(0), "First element should now be 8");
    }

    @Test
    @DisplayName("delete() removes middle element and size updates")
    void testDeleteMiddle() {
        LinkedList list = new LinkedList();
        list.add(1);
        list.add(2);
        list.add(3);
        list.add(4);
        list.delete(2); // Removes 3
        assertEquals(3, list.size(), "size() should return 3 after deleting index 2");
        assertEquals(4, list.get(2), "Element at index 2 should now be 4");
    }

    @Test
    @DisplayName("delete() removes last element and size updates")
    void testDeleteLast() {
        LinkedList list = new LinkedList();
        list.add(5);
        list.add(6);
        list.add(7);
        list.delete(2);
        assertEquals(2, list.size(), "size() should return 2 after deleting last element");
        assertThrows(IndexOutOfBoundsException.class, () -> list.get(2), "Accessing deleted index should throw");
    }

    @Test
    @DisplayName("delete() throws IndexOutOfBoundsException for invalid index")
    void testDeleteInvalidIndex() {
        LinkedList list = new LinkedList();
        list.add(1);
        list.add(2);
        assertThrows(IndexOutOfBoundsException.class, () -> list.delete(-1), "Negative index should throw");
        assertThrows(IndexOutOfBoundsException.class, () -> list.delete(2), "Index equal to size should throw");
        assertThrows(IndexOutOfBoundsException.class, () -> list.delete(100), "Large index should throw");
    }

    @Test
    @DisplayName("delete() on single-element list makes list empty")
    void testDeleteOnlyElement() {
        LinkedList list = new LinkedList();
        list.add(99);
        list.delete(0);
        assertEquals(0, list.size(), "List should be empty after deleting only element");
        assertThrows(IndexOutOfBoundsException.class, () -> list.get(0), "Getting from empty list should throw");
    }
}


MainTest.java

Een praktische gids voor Java-gegevensstructuren en collecties. Verken lijsten, gekoppelde lijsten, wachtrijen, deques, stacks en maps, terwijl u oefent met CRUD-bewerkingen, algoritmische complexiteit en praktijkgerichte uitdagingen zoals bibliotheekbeheer en browsergeschiedenis.

Een praktische gids voor datastructuren en collecties in Java. Verken lijsten, gekoppelde lijsten, wachtrijen, deques, stacks en maps, met oefening in CRUD-bewerkingen, algoritmische complexiteit en praktijkgerichte uitdagingen zoals bibliotheekbeheer en browsergeschiedenis.

Uitdaging: Implementatie van Size- en Delete-methoden in LinkedList

Oplossing