ListsTransformerTest

package com.talosdigital.timetracking.endpoint.transformer;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;

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

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

@RunWith(MockitoJUnitRunner.class)
public class ListsTransformerTest {

    private ListsTransformer listsTransformer;

    private List<Integer> dtos;
    private List<String> entities;

    @Before
    public void setUp() {
        listsTransformer = new ListsTransformer();

        dtos = new ArrayList<Integer>();
        entities = new ArrayList<String>();
        for (int i = 1; i < 5; i++) {
            dtos.add(i);
            entities.add(String.valueOf(i));
        }
    }

    @Test
    public void toDtos() {
        List<Integer> dtos = listsTransformer.toDtos(entities);
        assertEquals(this.dtos, dtos);
    }

    @Test
    public void toEntities() {
        List<String> entities = listsTransformer.toEntities(dtos);
        assertEquals(this.entities, entities);
    }

    @Test
    public void toDtos_emptyList() {
        entities.clear();
        List<Integer> dtos = listsTransformer.toDtos(entities);
        assertTrue(dtos.isEmpty());
    }

    @Test
    public void toEntities_emptyList() {
        dtos.clear();
        List<String> entities = listsTransformer.toEntities(dtos);
        assertTrue(entities.isEmpty());
    }
}

class ListsTransformer extends Transformer<Integer, String> {

    @Override
    public Integer toDto(String entity) {
        return Integer.valueOf(entity);
    }

    @Override
    public String toEntity(Integer dto) {
        return dto.toString();
    }
}