feat: Adds support for custom channel handle urls with tab paths (ex: {INSTANCE}/markrober/streams) (#5811)

* feat: add support for additional channel urls (:user/:tab)

* fix: check known_tabs against downcased selected_tab

* rebase, remove whitespace and move route to the correct place

---------

Co-authored-by: Fijxu <fijxu@nadeko.net>

src/invidious/routes/channels.cr

@@ -359,6 +359,17 @@ module Invidious::Routes::Channels
     "posts",
   }
 
+  def self.potential_brand_redirect(env)
+    # Check for known tab in url before trying to brand_redirect (avoids unneeded request to YouTube)
+    selected_tab = env.params.url["tab"]?.try &.downcase
+
+    if KNOWN_TABS.includes? selected_tab
+      brand_redirect(env)
+    else
+      Invidious::Routes::Misc.home(env)
+    end
+  end
+
   # Redirects brand url channels to a normal /channel/:ucid route
   def self.brand_redirect(env)
     locale = env.get("preferences").as(Preferences).locale
@@ -381,7 +392,7 @@ module Invidious::Routes::Channels
       return Errors.error_template(404, I18n.translate(locale, "This channel does not exist."))
     end
 
-    selected_tab = env.params.url["tab"]?
+    selected_tab = env.params.url["tab"]?.try &.downcase
 
     if KNOWN_TABS.includes? selected_tab
       url = "/channel/#{ucid}/#{selected_tab}"

src/invidious/routing.cr

@@ -146,6 +146,9 @@ module Invidious::Routing
     get "/user/:user", Routes::Channels, :brand_redirect
     get "/user/:user/:tab", Routes::Channels, :brand_redirect
 
+    # /linuxtechtips/streams
+    get "/:user/:tab", Routes::Channels, :potential_brand_redirect
+
     # /@LinusTechTips (Handle)
     get "/@:user", Routes::Channels, :brand_redirect
     get "/@:user/:tab", Routes::Channels, :brand_redirect