Add spec for extract_plid

spec/helpers_spec.cr

@@ -9,6 +9,7 @@ require "../src/invidious/channels"
 require "../src/invidious/comments"
 require "../src/invidious/playlists"
 require "../src/invidious/search"
+require "../src/invidious/trending"
 require "../src/invidious/users"
 
 describe "Helper" do
@@ -124,6 +125,15 @@ describe "Helper" do
     end
   end
 
+  describe "#extract_plid" do
+    it "correctly extracts playlist ID from trending URL" do
+      extract_plid("/feed/trending?bp=4gIuCggvbS8wNHJsZhIiUExGZ3F1TG5MNTlhbVBud2pLbmNhZUp3MDYzZlU1M3Q0cA%3D%3D").should eq("PLFgquLnL59amPnwjKncaeJw063fU53t4p")
+      extract_plid("/feed/trending?bp=4gIvCgkvbS8wYnp2bTISIlBMaUN2Vkp6QnVwS2tDaFNnUDdGWFhDclo2aEp4NmtlTm0%3D").should eq("PLiCvVJzBupKkChSgP7FXXCrZ6hJx6keNm")
+      extract_plid("/feed/trending?bp=4gIuCggvbS8wNWpoZxIiUEwzWlE1Q3BOdWxRbUtPUDNJekdsYWN0V1c4dklYX0hFUA%3D%3D").should eq("PL3ZQ5CpNulQmKOP3IzGlactWW8vIX_HEP")
+      extract_plid("/feed/trending?bp=4gIuCggvbS8wMnZ4bhIiUEx6akZiYUZ6c21NUnFhdEJnVTdPeGNGTkZhQ2hqTkVERA%3D%3D").should eq("PLzjFbaFzsmMRqatBgU7OxcFNFaChjNEDD")
+    end
+  end
+
   describe "#sign_token" do
     it "correctly signs a given hash" do
       token = {