Add tests for live chat functionality in YouTube extractors

Author: Ecomont

extractor/src/test/java/org/schabi/newpipe/extractor/services/DefaultStreamExtractorTest.java

@@ -83,6 +83,7 @@ public abstract class DefaultStreamExtractorTest extends DefaultExtractorTest<St
     public int expectedStreamSegmentsCount() { return -1; } // return 0 or greater to test (default is -1 to ignore)
     public List<MetaInfo> expectedMetaInfo() throws MalformedURLException { return Collections.emptyList(); } // default: no metadata info available
     public ContentAvailability expectedContentAvailability() { return ContentAvailability.UNKNOWN; } // default: unknown content availability
+    public boolean expectedHasLiveChat() { return false; } // default: no live chat available
 
     @Test
     @Override
@@ -480,4 +481,9 @@ public void testMetaInfo() throws Exception {
     public void testContentAvailability() throws Exception {
         assertEquals(expectedContentAvailability(), extractor().getContentAvailability());
     }
+
+    @Test
+    public void testHasLiveChat() throws Exception {
+        assertEquals(expectedHasLiveChat(), extractor().hasLiveChat());
+    }
 }

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

@@ -427,4 +427,50 @@ public void testGetCommentsFormatting() throws IOException, ExtractionException
             assertContains("<b>", firstComment.getCommentText().getContent());
         }
     }
+
+    /**
+     * Test live chat mode behavior on a regular video extractor.
+     * Does not extend {@link Base} because these tests do not need network/mock data.
+     */
+    public static class LiveChatMode {
+        private static final String URL = "https://www.youtube.com/watch?v=D00Au7k3i6o";
+
+        @org.junit.jupiter.api.BeforeAll
+        static void setUp() {
+            org.schabi.newpipe.extractor.InitNewPipeTest.initEmpty();
+            org.schabi.newpipe.extractor.NewPipe.init(new org.schabi.newpipe.extractor.downloader.Downloader() {
+                @org.jetbrains.annotations.NotNull
+                @Override
+                public org.schabi.newpipe.extractor.downloader.Response execute(
+                        @org.jetbrains.annotations.NotNull final org.schabi.newpipe.extractor.downloader.Request request) {
+                    throw new UnsupportedOperationException("No communication expected");
+                }
+            });
+        }
+
+        private YoutubeCommentsExtractor createExtractor() throws Exception {
+            return (YoutubeCommentsExtractor) YouTube.getCommentsExtractor(URL);
+        }
+
+        @Test
+        void testIsLiveChatDefaultFalse() throws Exception {
+            assertFalse(createExtractor().isLiveChat());
+        }
+
+        @Test
+        void testSetLiveChatContinuationActivatesLiveChat() throws Exception {
+            final YoutubeCommentsExtractor extractor = createExtractor();
+            assertFalse(extractor.isLiveChat());
+            extractor.setLiveChatContinuation("test-continuation");
+            assertTrue(extractor.isLiveChat());
+        }
+
+        @Test
+        void testCommentsDisabledIsFalseInLiveChatMode() throws Exception {
+            final YoutubeCommentsExtractor extractor = createExtractor();
+            extractor.setLiveChatContinuation("test-continuation");
+            assertTrue(extractor.isLiveChat());
+            assertFalse(extractor.isCommentsDisabled());
+        }
+    }
 }

extractor/src/test/java/org/schabi/newpipe/extractor/services/youtube/stream/YoutubeStreamExtractorLivestreamTest.java

@@ -1,5 +1,7 @@
 package org.schabi.newpipe.extractor.services.youtube.stream;
 
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.schabi.newpipe.extractor.ServiceList.YouTube;
 
 import org.junit.jupiter.api.Test;
@@ -38,7 +40,15 @@ public void testUploaderName() throws Exception {
     @Override public String expectedOriginalUrlContains() { return URL; }
 
     @Override public StreamType expectedStreamType() { return StreamType.LIVE_STREAM; }
+    @Override public boolean expectedHasLiveChat() { return true; }
     @Override public String expectedUploaderName() { return "Lofi Girl"; }
+
+    @Test
+    void testLiveChatContinuationNotNull() throws Exception {
+        final String continuation = extractor().getLiveChatContinuation();
+        assertNotNull(continuation);
+        assertFalse(continuation.isEmpty());
+    }
     @Override public String expectedUploaderUrl() { return "https://www.youtube.com/channel/UCSJ4gkVC6NrvII8umztf0Ow"; }
     @Override public long expectedUploaderSubscriberCountAtLeast() { return 9_800_000; }
     @Override public List<String> expectedDescriptionContains() {