Unit test Guava cache

TestGuavaCache.java

import com.google.common.cache.*;
import org.junit.Test;

import java.util.HashMap;
import java.util.Map;

import static org.fest.assertions.Assertions.assertThat;

/**
 * Created by Tu Pham Phuong - phamptu@gmail.com on 7/2/15.
 */
public class TestGuavaCache {
    @Test
    public void whenCacheMiss_thenValueIsComputed() {
        CacheLoader<String, String> loader = new CacheLoader<String, String>() {
            @Override
            public String load(String key) {
                return key.toUpperCase();
            }
        };

        LoadingCache<String, String> cache = CacheBuilder.newBuilder().build(loader);

        assertThat(0).isEqualTo((int) cache.size());
        assertThat("HELLO").isEqualTo(cache.getUnchecked("hello"));
        assertThat(1).isEqualTo((int) cache.size());
    }

    @Test
    public void whenPreloadCache_thenUsePutAll() {
        CacheLoader<String, String> loader = new CacheLoader<String, String>() {
            @Override
            public String load(String key) {
                return key.toUpperCase();
            }
        };

        LoadingCache<String, String> cache = CacheBuilder.newBuilder().build(loader);

        Map<String, String> map = new HashMap<String, String>();
        map.put("first", "FIRST");
        map.put("second", "SECOND");
        cache.putAll(map);

        assertThat(2).isEqualTo((int) cache.size());
    }

    @Test
    public void whenEntryRemovedFromCache_thenNotify() {
        CacheLoader<String, String> loader = new CacheLoader<String, String>() {
            @Override
            public String load(final String key) {
                return key.toUpperCase();
            }
        };

        RemovalListener<String, String> listener = new RemovalListener<String, String>() {
            @Override
            public void onRemoval(RemovalNotification<String, String> n){
                if (n.wasEvicted()) {
                    String cause = n.getCause().name();
                    assertThat(RemovalCause.SIZE.toString()).isEqualTo(cause);
                }
            }
        };

        LoadingCache<String, String> cache = CacheBuilder.newBuilder()
                .maximumSize(3)
                .removalListener(listener)
                .build(loader);

        cache.getUnchecked("first");
        cache.getUnchecked("second");
        cache.getUnchecked("third");
        cache.getUnchecked("last");
        assertThat(3).isEqualTo((int) cache.size());
    }
}