simplify youtube channels url detection

commafeed-server/src/test/java/com/commafeed/backend/urlprovider/YoutubeFeedURLProviderTest.java

@@ -0,0 +1,22 @@
+package com.commafeed.backend.urlprovider;
+
+import org.junit.jupiter.api.Assertions;
+import org.junit.jupiter.api.Test;
+
+class YoutubeFeedURLProviderTest {
+
+	private final YoutubeFeedURLProvider provider = new YoutubeFeedURLProvider();
+
+	@Test
+	void matchesYoutubeChannelURL() {
+		Assertions.assertEquals("https://www.youtube.com/feeds/videos.xml?channel_id=abc",
+				provider.get("https://www.youtube.com/channel/abc", null));
+	}
+
+	@Test
+	void doesNotmatchYoutubeChannelURL() {
+		Assertions.assertNull(provider.get("https://www.anothersite.com/channel/abc", null));
+		Assertions.assertNull(provider.get("https://www.youtube.com/user/abc", null));
+	}
+
+}