package Wojciech.z2;

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

class fridgeStateTest {

    private fridgeState fs;

    @BeforeAll
    static void init(){
        System.out.println("Tests have been initialized.");
    }

    @BeforeEach
    void beforeEach(){
        System.out.println("Next test...");
    }

    @Test
    @DisplayName("Add an item")
    void addItem(){
        fs = new fridgeState();

        fs.items.add("Kot");
        assertTrue(fs.items.contains("Kot"));
        assertEquals("Kot",fs.items.get(0));
    }

    @Test
    @DisplayName("Remove an item with contains")
    void removeItem(){
        fs = new fridgeState();

        fs.items.add("Kot");
        fs.items.add("Pies");
        fs.items.remove("Kot");

        assertFalse(fs.items.contains("Kot"));
    }


    @Test
    @DisplayName("Remove an item with an exception")
    void removeItem2(){
        fs = new fridgeState();
        String kot = "Kot";
        fs.items.add(kot);
        fs.items.remove(kot);

        assertFalse(fs.items.contains(kot));
        assertTrue(fs.items.isEmpty());
        assertThrows(IndexOutOfBoundsException.class,()-> fs.items.get(0));
    }

    @Test
    @DisplayName("List is not an empty object")
    void emptyList(){
        fs = null;
        assertNotNull(fs,()->"Object is not empty");
    }
}

==========================================================================================

package Wojciech.z2;

import java.util.ArrayList;
import java.util.List;

public class fridgeState {

    List<String> items = new ArrayList<String>();

    public void addItem(String i){
        items.add(i);
    }

    public void removeItem(String i){
        items.remove(i);
    }
}