DefaultFeedItemStoreTest.java

package org.eclipse.recommenders.news.impl.poll;

import static org.hamcrest.Matchers.*;
import static org.junit.Assert.assertThat;

import java.io.ByteArrayInputStream;
import java.io.InputStream;
import java.net.URI;
import java.nio.charset.StandardCharsets;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.List;
import java.util.Locale;

import org.eclipse.recommenders.news.api.NewsItem;
import org.junit.Test;

public class DefaultFeedItemStoreTest {

    private static final URI FEED_URI = URI.create("http://www.example.org/feed.xml");

    private static final NewsItem FIRST_ITEM = new NewsItem("Item 1", new Date(0L),
            URI.create("http://www.example.org/items/1"), null);
    private static final NewsItem SECOND_ITEM = new NewsItem("Item 2", new Date(1000L),
            URI.create("http://www.example.org/items/2"), null);

    @Test
    public void testUpdateWithAddedItems() throws Exception {
        DefaultFeedItemStore sut = new DefaultFeedItemStore();
        sut.udpate(FEED_URI, asInputStream(FIRST_ITEM), null);

        List<NewsItem> newItems = sut.udpate(FEED_URI, asInputStream(FIRST_ITEM, SECOND_ITEM), null);

        assertThat(newItems, contains(SECOND_ITEM));
        assertThat(newItems, hasSize(1));
    }

    @Test
    public void testUpdateWithRemovedItems() throws Exception {
        DefaultFeedItemStore sut = new DefaultFeedItemStore();
        sut.udpate(FEED_URI, asInputStream(FIRST_ITEM, SECOND_ITEM), null);

        List<NewsItem> newItems = sut.udpate(FEED_URI, asInputStream(SECOND_ITEM), null);

        assertThat(newItems, hasSize(0));
    }

    @Test
    public void testUpdateWithoutChanges() throws Exception {
        DefaultFeedItemStore sut = new DefaultFeedItemStore();
        sut.udpate(FEED_URI, asInputStream(FIRST_ITEM, SECOND_ITEM), null);

        List<NewsItem> newItems = sut.udpate(FEED_URI, asInputStream(FIRST_ITEM, SECOND_ITEM), null);

        assertThat(newItems, hasSize(0));
    }

    @Test
    public void testGetFeedItemsWithoutUpdate() {
        DefaultFeedItemStore sut = new DefaultFeedItemStore();

        List<NewsItem> items = sut.getNewsItems(FEED_URI);

        assertThat(items, hasSize(0));
    }

    @Test
    public void testGetFeedItemsAfterEmptyUpdate() throws Exception {
        DefaultFeedItemStore sut = new DefaultFeedItemStore();
        sut.udpate(FEED_URI, asInputStream(), null);

        List<NewsItem> items = sut.getNewsItems(FEED_URI);

        assertThat(items, hasSize(0));
    }

    @Test
    public void testGetFeedItemsAfterSingleUpdate() throws Exception {
        DefaultFeedItemStore sut = new DefaultFeedItemStore();
        sut.udpate(FEED_URI, asInputStream(FIRST_ITEM), null);

        List<NewsItem> items = sut.getNewsItems(FEED_URI);

        assertThat(items, contains(FIRST_ITEM));
        assertThat(items, hasSize(1));
    }

    @Test
    public void testGetFeedItemsAfterTwoComplementaryUpdates() throws Exception {
        DefaultFeedItemStore sut = new DefaultFeedItemStore();
        sut.udpate(FEED_URI, asInputStream(FIRST_ITEM), null);
        sut.udpate(FEED_URI, asInputStream(SECOND_ITEM), null);

        List<NewsItem> items = sut.getNewsItems(FEED_URI);

        assertThat(items, contains(SECOND_ITEM));
        assertThat(items, hasSize(1));
    }

    @Test
    public void testGetFeedItemsAfterTwoIncrementalUpdates() throws Exception {
        DefaultFeedItemStore sut = new DefaultFeedItemStore();
        sut.udpate(FEED_URI, asInputStream(FIRST_ITEM), null);
        sut.udpate(FEED_URI, asInputStream(FIRST_ITEM, SECOND_ITEM), null);

        List<NewsItem> items = sut.getNewsItems(FEED_URI);

        assertThat(items, contains(FIRST_ITEM, SECOND_ITEM));
        assertThat(items, hasSize(2));
    }

    private static InputStream asInputStream(NewsItem... items) {
        DateFormat formatter = new SimpleDateFormat("EEE, dd MMM yyyy HH:mm:ss zzz", Locale.ENGLISH);

        StringBuilder rss = new StringBuilder();
        rss.append("<?xml version='1.0' encoding='UTF-8'?>");
        rss.append("<rss version='2.0'>");
        rss.append("<channel>");
        rss.append("<title>Feed</title>");

        for (NewsItem item : items) {
            rss.append("<item>");
            rss.append("<title>").append(item.getTitle()).append("</title>");
            rss.append("<pubDate>").append(formatter.format(item.getDate())).append("</pubDate>");
            rss.append("<link>").append(item.getUri().toString()).append("</link>");
            rss.append("</item>");
        }
        rss.append("</channel>");
        rss.append("</rss>");

        return new ByteArrayInputStream(rss.toString().getBytes(StandardCharsets.UTF_8));
    }
}