Add bin and edit workflow

bin/gems/html-proofer-5.0.10/lib/html_proofer/check/favicon.rb

@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+module HTMLProofer
+  class Check
+    class Favicon < HTMLProofer::Check
+      def run
+        found = false
+        @html.css("link").each do |node|
+          @favicon = create_element(node)
+
+          next if @favicon.ignore?
+
+          break if (found = @favicon.node["rel"].split.last.eql?("icon"))
+        end
+
+        return if immediate_redirect?
+
+        if found
+          if @favicon.url.protocol_relative?
+            add_failure(
+              "favicon link #{@favicon.url} is a protocol-relative URL, use explicit https:// instead",
+              element: @favicon,
+            )
+          elsif @favicon.url.remote?
+            add_to_external_urls(@favicon.url, @favicon.line)
+          elsif !@favicon.url.exists?
+            add_failure(
+              "internal favicon #{@favicon.url.raw_attribute} does not exist",
+              element: @favicon,
+            )
+          end
+        else
+          add_failure("no favicon provided")
+        end
+      end
+
+      private
+
+      # allow any instant-redirect meta tag
+      def immediate_redirect?
+        @html.xpath("//meta[@http-equiv='refresh']").attribute("content").value.start_with?("0;")
+      rescue StandardError
+        false
+      end
+    end
+  end
+end