Merge pull request #215 from gzsombor/fix-search-paging

Fix search result paging

extractor/src/main/java/org/schabi/newpipe/extractor/services/media_ccc/extractors/MediaCCCSearchExtractor.java

@@ -48,6 +48,7 @@ public class MediaCCCSearchExtractor extends SearchExtractor {
     @Override
     public InfoItemsPage<InfoItem> getInitialPage() throws IOException, ExtractionException {
         InfoItemsSearchCollector searchItems = getInfoItemSearchCollector();
+        searchItems.reset();
 
         if(getLinkHandler().getContentFilters().contains(CONFERENCES)
                 || getLinkHandler().getContentFilters().contains(ALL)

extractor/src/main/java/org/schabi/newpipe/extractor/services/soundcloud/SoundcloudSearchExtractor.java

@@ -76,6 +76,7 @@ public class SoundcloudSearchExtractor extends SearchExtractor {
 
     private InfoItemsCollector<InfoItem, InfoItemExtractor> collectItems(JsonArray searchCollection) {
         final InfoItemsSearchCollector collector = getInfoItemSearchCollector();
+        collector.reset();
 
         for (Object result : searchCollection) {
             if (!(result instanceof JsonObject)) continue;

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/extractors/YoutubeSearchExtractor.java

@@ -106,6 +106,7 @@ public class YoutubeSearchExtractor extends SearchExtractor {
 
     private InfoItemsSearchCollector collectItems(Document doc) throws NothingFoundException  {
         InfoItemsSearchCollector collector = getInfoItemSearchCollector();
+        collector.reset();
 
         Element list = doc.select("ol[class=\"item-section\"]").first();
         final TimeAgoParser timeAgoParser = getTimeAgoParser();

extractor/src/test/java/org/schabi/newpipe/extractor/services/youtube/search/YoutubeSearchPagingTest.java

@@ -0,0 +1,71 @@
+package org.schabi.newpipe.extractor.services.youtube.search;
+
+import static java.util.Collections.singletonList;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+import static org.schabi.newpipe.extractor.ServiceList.YouTube;
+
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.schabi.newpipe.DownloaderTestImpl;
+import org.schabi.newpipe.extractor.InfoItem;
+import org.schabi.newpipe.extractor.ListExtractor;
+import org.schabi.newpipe.extractor.NewPipe;
+import org.schabi.newpipe.extractor.services.youtube.extractors.YoutubeSearchExtractor;
+import org.schabi.newpipe.extractor.services.youtube.linkHandler.YoutubeSearchQueryHandlerFactory;
+
+public class YoutubeSearchPagingTest {
+    private static ListExtractor.InfoItemsPage<InfoItem> page1;
+    private static ListExtractor.InfoItemsPage<InfoItem> page2;
+    private static Set<String> urlList1;
+    private static Set<String> urlList2;
+    private static int page1Size;
+    private static int page2Size;
+
+    @BeforeClass
+    public static void setUpClass() throws Exception {
+        NewPipe.init(DownloaderTestImpl.getInstance());
+
+        YoutubeSearchExtractor extractor = (YoutubeSearchExtractor) YouTube.getSearchExtractor("cirque du soleil",
+                singletonList(YoutubeSearchQueryHandlerFactory.VIDEOS), null);
+
+        extractor.fetchPage();
+        page1 = extractor.getInitialPage();
+        urlList1 = extractUrls(page1.getItems());
+        assertTrue("failed to load search result page one: too few items", 15 < page1.getItems().size());
+        page1Size = page1.getItems().size();
+        assertEquals("duplicated items in search result on page one", page1Size, urlList1.size());
+
+        assertTrue("search result has no second page", page1.hasNextPage());
+        assertNotNull("next page url is null", page1.getNextPageUrl());
+        page2 = extractor.getPage(page1.getNextPageUrl());
+        urlList2 = extractUrls(page2.getItems());
+        page2Size = page2.getItems().size();
+    }
+
+    private static Set<String> extractUrls(List<InfoItem> list) {
+        Set<String> result = new HashSet<>();
+        for (InfoItem item : list) {
+            result.add(item.getUrl());
+        }
+        return result;
+    }
+
+    @Test
+    public void secondPageUniqueVideos() {
+        assertEquals("Second search result page has duplicated items", page2Size, urlList2.size());
+    }
+
+    @Test
+    public void noRepeatingVideosInPages() {
+        Set<String> intersection = new HashSet<>(urlList2);
+        intersection.retainAll(urlList1);
+        assertEquals("Found the same item on first AND second search page", 0, intersection.size());
+    }
+
+}