Adress the last requested changes + update YoutubeCommentsExtractor mocks

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/YoutubeParsingHelper.java

@@ -78,7 +78,8 @@ public class YoutubeParsingHelper {
     private static String[] youtubeMusicKey;
 
     private static boolean keyAndVersionExtracted = false;
-    private static Boolean areHardcodedClientVersionAndKeyValidValue = null;
+    @SuppressWarnings("OptionalUsedAsFieldOrParameterType")
+    private static Optional<Boolean> hardcodedClientVersionAndKeyValid = Optional.empty();
 
     private static Random numberGenerator = new Random();
 
@@ -308,10 +309,10 @@ public class YoutubeParsingHelper {
         }
     }
 
-    public static boolean areHardcodedClientVersionAndKeyValid()
+    public static Optional<Boolean> areHardcodedClientVersionAndKeyValid()
             throws IOException, ExtractionException {
-        if (areHardcodedClientVersionAndKeyValidValue != null) {
+        if (hardcodedClientVersionAndKeyValid.isPresent()) {
-            return areHardcodedClientVersionAndKeyValidValue;
+            return hardcodedClientVersionAndKeyValid;
         }
         // @formatter:off
         final byte[] body = JsonWriter.string()
@@ -343,12 +344,12 @@ public class YoutubeParsingHelper {
         final String responseBody = response.responseBody();
         final int responseCode = response.responseCode();
 
-        return areHardcodedClientVersionAndKeyValidValue = responseBody.length() > 5000
+        return hardcodedClientVersionAndKeyValid = Optional.of(responseBody.length() > 5000
-                && responseCode == 200; // Ensure to have a valid response
+                && responseCode == 200); // Ensure to have a valid response
     }
 
     private static void extractClientVersionAndKey() throws IOException, ExtractionException {
-        // Don't extract the client version and the innertube key if it has been already extracted
+        // Don't extract the client version and the InnerTube key if it has been already extracted
         if (keyAndVersionExtracted) return;
         // Don't provide a search term in order to have a smaller response
         final String url = "https://www.youtube.com/results?search_query=&ucbcb=1";
@@ -424,7 +425,7 @@ public class YoutubeParsingHelper {
      */
     public static String getClientVersion() throws IOException, ExtractionException {
         if (!isNullOrEmpty(clientVersion)) return clientVersion;
-        if (areHardcodedClientVersionAndKeyValid()) {
+        if (areHardcodedClientVersionAndKeyValid().orElse(false)) {
             return clientVersion = HARDCODED_CLIENT_VERSION;
         }
 
@@ -437,7 +438,7 @@ public class YoutubeParsingHelper {
      */
     public static String getKey() throws IOException, ExtractionException {
         if (!isNullOrEmpty(key)) return key;
-        if (areHardcodedClientVersionAndKeyValid()) {
+        if (areHardcodedClientVersionAndKeyValid().orElse(false)) {
             return key = HARDCODED_KEY;
         }
 

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

@@ -81,30 +81,31 @@ public class YoutubeChannelExtractor extends ChannelExtractor {
     @Override
     public void onFetchPage(@Nonnull final Downloader downloader) throws IOException,
             ExtractionException {
-        final String channel_path = super.getId();
+        final String channelPath = super.getId();
-        final String[] channelInfo = channel_path.split("/");
+        final String[] channelId = channelPath.split("/");
         String id = "";
         // If the url is an URL which is not a /channel URL, we need to use the
-        // navigation/resolve_url endpoint of the youtubei API to get the channel id. Otherwise, we
+        // navigation/resolve_url endpoint of the InnerTube API to get the channel id. Otherwise,
-        // couldn't get information about the channel associated with this URL, if there is one.
+        // we couldn't get information about the channel associated with this URL, if there is one.
-        if (!channelInfo[0].equals("channel")) {
+        if (!channelId[0].equals("channel")) {
             final byte[] body = JsonWriter.string(prepareJsonBuilder(getExtractorLocalization(),
                     getExtractorContentCountry())
-                    .value("url", "https://www.youtube.com/" + channel_path)
+                    .value("url", "https://www.youtube.com/" + channelPath)
                     .done())
                     .getBytes(UTF_8);
 
             final JsonObject jsonResponse = getJsonPostResponse("navigation/resolve_url",
                     body, getExtractorLocalization());
 
-            if (jsonResponse.has("error")) {
+            if (!isNullOrEmpty(jsonResponse.getObject("error"))) {
-                if (jsonResponse.getInt("code") == 404) {
+                final JsonObject errorJsonObject = jsonResponse.getObject("error");
-                    throw new ContentNotAvailableException(
+                final int errorCode = errorJsonObject.getInt("code");
-                            "No channel associated with this user exists");
+                if (errorCode == 404) {
+                    throw new ContentNotAvailableException("This channel doesn't exist.");
                 } else {
                     throw new ContentNotAvailableException("Got error:\""
-                            + jsonResponse.getString("status") + "\": "
+                        + errorJsonObject.getString("status") + "\": "
-                            + jsonResponse.getString("message"));
+                        + errorJsonObject.getString("message"));
                 }
             }
 
@@ -128,7 +129,7 @@ public class YoutubeChannelExtractor extends ChannelExtractor {
                 redirectedChannelId = browseId;
             }
         } else {
-            id = channelInfo[1];
+            id = channelId[1];
         }
         JsonObject ajaxJson = null;
 
@@ -145,13 +146,14 @@ public class YoutubeChannelExtractor extends ChannelExtractor {
                     getExtractorLocalization());
 
             if (!isNullOrEmpty(jsonResponse.getObject("error"))) {
-                final int errorCode = jsonResponse.getObject("error").getInt("code");
+                final JsonObject errorJsonObject = jsonResponse.getObject("error");
-                if (errorCode == 400) {
+                final int errorCode = errorJsonObject.getInt("code");
+                if (errorCode == 404) {
                     throw new ContentNotAvailableException("This channel doesn't exist.");
                 } else {
                     throw new ContentNotAvailableException("Got error:\""
-                            + jsonResponse.getString("status") + "\": "
+                            + errorJsonObject.getString("status") + "\": "
-                            + jsonResponse.getString("message"));
+                            + errorJsonObject.getString("message"));
                 }
             }
 
@@ -330,13 +332,13 @@ public class YoutubeChannelExtractor extends ChannelExtractor {
                     .getArray("contents").getObject(0).getObject("itemSectionRenderer")
                     .getArray("contents").getObject(0).getObject("gridRenderer");
 
-            final List<String> channelInfo = new ArrayList<>();
+            final List<String> channelIds = new ArrayList<>();
-            channelInfo.add(getName());
+            channelIds.add(getName());
-            channelInfo.add(getUrl());
+            channelIds.add(getUrl());
             final JsonObject continuation = collectStreamsFrom(collector, gridRenderer
-                    .getArray("items"), channelInfo);
+                    .getArray("items"), channelIds);
 
-            nextPage = getNextPageFrom(continuation, channelInfo);
+            nextPage = getNextPageFrom(continuation, channelIds);
         }
 
         return new InfoItemsPage<>(collector, nextPage);
@@ -349,7 +351,7 @@ public class YoutubeChannelExtractor extends ChannelExtractor {
             throw new IllegalArgumentException("Page doesn't contain an URL");
         }
 
-        final List<String> channelInfos = page.getIds();
+        final List<String> channelIds = page.getIds();
 
         final StreamInfoItemsCollector collector = new StreamInfoItemsCollector(getServiceId());
         final Map<String, List<String>> headers = new HashMap<>();
@@ -365,14 +367,14 @@ public class YoutubeChannelExtractor extends ChannelExtractor {
                 .getObject("appendContinuationItemsAction");
 
         final JsonObject continuation = collectStreamsFrom(collector, sectionListContinuation
-                .getArray("continuationItems"), channelInfos);
+                .getArray("continuationItems"), channelIds);
 
-        return new InfoItemsPage<>(collector, getNextPageFrom(continuation, channelInfos));
+        return new InfoItemsPage<>(collector, getNextPageFrom(continuation, channelIds));
     }
 
     @Nullable
     private Page getNextPageFrom(final JsonObject continuations,
-                                 final List<String> channelInfo) throws IOException,
+                                 final List<String> channelIds) throws IOException,
             ExtractionException {
         if (isNullOrEmpty(continuations)) {
             return null;
@@ -388,23 +390,24 @@ public class YoutubeChannelExtractor extends ChannelExtractor {
                 .done())
                 .getBytes(UTF_8);
 
-        return new Page(YOUTUBEI_V1_URL + "browse?key=" + getKey(), null, channelInfo, null, body);
+        return new Page(YOUTUBEI_V1_URL + "browse?key=" + getKey(), null, channelIds, null, body);
     }
 
     /**
      * Collect streams from an array of items
      *
-     * @param collector the collector where videos will be commited
+     * @param collector  the collector where videos will be committed
      * @param videos     the array to get videos from
+     * @param channelIds the ids of the channel, which are its name and its URL
      * @return the continuation object
      */
     private JsonObject collectStreamsFrom(@Nonnull final StreamInfoItemsCollector collector,
                                           @Nonnull final JsonArray videos,
-                                          @Nonnull final List<String> channelInfo) {
+                                          @Nonnull final List<String> channelIds) {
         collector.reset();
 
-        final String uploaderName = channelInfo.get(0);
+        final String uploaderName = channelIds.get(0);
-        final String uploaderUrl = channelInfo.get(1);
+        final String uploaderUrl = channelIds.get(1);
         final TimeAgoParser timeAgoParser = getTimeAgoParser();
 
         JsonObject continuation = null;

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

@@ -189,7 +189,7 @@ public class YoutubeCommentsExtractor extends CommentsExtractor {
     public void onFetchPage(@Nonnull final Downloader downloader) throws IOException, ExtractionException {
         final Map<String, List<String>> requestHeaders = new HashMap<>();
         requestHeaders.put("User-Agent", singletonList(USER_AGENT));
-        final Response response = downloader.get(getUrl() + "&ucbcb=1", requestHeaders, getExtractorLocalization());
+        final Response response = downloader.get(getUrl(), requestHeaders, getExtractorLocalization());
         responseBody = YoutubeParsingHelper.unescapeDocument(response.responseBody());
         ytClientVersion = findValue(responseBody, "INNERTUBE_CONTEXT_CLIENT_VERSION\":\"", "\"");
         ytClientName = Parser.matchGroup1(YT_CLIENT_NAME_PATTERN, responseBody);

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

@@ -85,7 +85,6 @@ public class YoutubeMixPlaylistExtractor extends PlaylistExtractor {
         if (isNullOrEmpty(playlistData)) throw new ExtractionException(
                 "Could not get playlistData");
         cookieValue = extractCookieValue(COOKIE_NAME, response);
-
     }
 
     @Nonnull

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

@@ -962,7 +962,8 @@ public class YoutubeStreamExtractor extends StreamExtractor {
                         }
                     }
                 }
-            } else if (streamingData.has("formats")) {
+            }
+            if (streamingData.has("formats")) {
                 final JsonArray formats = streamingData.getArray("formats");
                 if (!isNullOrEmpty(formats)) {
                     for (final Object format : formats) {

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/linkHandler/YoutubeSearchQueryHandlerFactory.java

@@ -3,6 +3,7 @@ package org.schabi.newpipe.extractor.services.youtube.linkHandler;
 import org.schabi.newpipe.extractor.exceptions.ParsingException;
 import org.schabi.newpipe.extractor.linkhandler.SearchQueryHandlerFactory;
 
+import javax.annotation.Nonnull;
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
 import java.util.List;
@@ -26,24 +27,31 @@ public class YoutubeSearchQueryHandlerFactory extends SearchQueryHandlerFactory
     private static final String SEARCH_URL = "https://www.youtube.com/results?search_query=";
     private static final String MUSIC_SEARCH_URL = "https://music.youtube.com/search?q=";
 
+    @Nonnull
     public static YoutubeSearchQueryHandlerFactory getInstance() {
         return new YoutubeSearchQueryHandlerFactory();
     }
 
     @Override
-    public String getUrl(String searchString, List<String> contentFilters, String sortFilter) throws ParsingException {
+    public String getUrl(final String searchString,
+                         @Nonnull final List<String> contentFilters,
+                         final String sortFilter) throws ParsingException {
         try {
             if (!contentFilters.isEmpty()) {
-                switch (contentFilters.get(0)) {
+                final String contentFilter = contentFilters.get(0);
+                switch (contentFilter) {
                     case ALL:
                     default:
                         break;
                     case VIDEOS:
-                        return SEARCH_URL + URLEncoder.encode(searchString, UTF_8) + "&sp=EgIQAQ%253D%253D";
+                        return SEARCH_URL + URLEncoder.encode(searchString, UTF_8)
+                                + "&sp=EgIQAQ%253D%253D";
                     case CHANNELS:
-                        return SEARCH_URL + URLEncoder.encode(searchString, UTF_8) + "&sp=EgIQAg%253D%253D";
+                        return SEARCH_URL + URLEncoder.encode(searchString, UTF_8)
+                                + "&sp=EgIQAg%253D%253D";
                     case PLAYLISTS:
-                        return SEARCH_URL + URLEncoder.encode(searchString, UTF_8) + "&sp=EgIQAw%253D%253D";
+                        return SEARCH_URL + URLEncoder.encode(searchString, UTF_8)
+                                + "&sp=EgIQAw%253D%253D";
                     case MUSIC_SONGS:
                     case MUSIC_VIDEOS:
                     case MUSIC_ALBUMS:
@@ -54,7 +62,7 @@ public class YoutubeSearchQueryHandlerFactory extends SearchQueryHandlerFactory
             }
 
             return SEARCH_URL + URLEncoder.encode(searchString, UTF_8);
-        } catch (UnsupportedEncodingException e) {
+        } catch (final UnsupportedEncodingException e) {
             throw new ParsingException("Could not encode query", e);
         }
     }
@@ -70,10 +78,11 @@ public class YoutubeSearchQueryHandlerFactory extends SearchQueryHandlerFactory
                 MUSIC_VIDEOS,
                 MUSIC_ALBUMS,
                 MUSIC_PLAYLISTS
-//                MUSIC_ARTISTS
+                // MUSIC_ARTISTS
         };
     }
 
+    @Nonnull
     public static String getSearchParameter(final String contentFilter) {
         if (isNullOrEmpty(contentFilter)) return "";
         switch (contentFilter) {

extractor/src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubeParsingHelperTest.java

@@ -27,7 +27,7 @@ public class YoutubeParsingHelperTest {
     @Test
     public void testAreHardcodedClientVersionAndKeyValid() throws IOException, ExtractionException {
         assertTrue("Hardcoded client version and key are not valid anymore",
-                YoutubeParsingHelper.areHardcodedClientVersionAndKeyValid());
+                YoutubeParsingHelper.areHardcodedClientVersionAndKeyValid().orElse(false));
     }
 
     @Test
@@ -44,7 +44,7 @@ public class YoutubeParsingHelperTest {
     }
 
     @Test
-    public void testConvertFromGoogleCacheUrl() throws ParsingException {
+    public void testConvertFromGoogleCacheUrl() {
         assertEquals("https://mohfw.gov.in/",
                 YoutubeParsingHelper.extractCachedUrlIfNeeded("https://webcache.googleusercontent.com/search?q=cache:https://mohfw.gov.in/"));
         assertEquals("https://www.infektionsschutz.de/coronavirus-sars-cov-2.html",