FEATURE: Support Spotify Onebox (#27540)

lib/onebox/engine/spotify_onebox.rb

@@ -0,0 +1,31 @@
+# frozen_string_literal: true
+
+module Onebox
+  module Engine
+    class SpotifyOnebox
+      include Engine
+      include StandardEmbed
+
+      matches_regexp(%r{^https?://open\.spotify/\.com})
+      requires_iframe_origins "https://open.spotify.com"
+      always_https
+
+      def to_html
+        oembed = get_oembed
+        oembed.html
+      end
+
+      def placeholder_html
+        oembed = get_oembed
+        return if oembed.thumbnail_url.blank?
+        "<img src='#{oembed.thumbnail_url}' title='#{oembed.title}' alt='#{oembed.title}' height='#{oembed.thumbnail_height}' width='#{oembed.thumbnail_width}'>"
+      end
+
+      protected
+
+      def get_oembed_url
+        "https://open.spotify.com/oembed?url=#{url}"
+      end
+    end
+  end
+end