refactor: configure gem defaults on boot and remove manual config merging

Gemfile

@@ -4,12 +4,12 @@ source 'https://rubygems.org'
 
 git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 
-gem 'html2rss', '~> 0.19'
+# gem 'html2rss', '~> 0.19'
 # gem 'html2rss', github: 'html2rss/html2rss', branch: 'master'
 gem 'html2rss-configs', github: 'html2rss/html2rss-configs'
 
 # Use these instead of the two above (uncomment them) when developing locally:
-# gem 'html2rss', path: '../html2rss'
+gem 'html2rss', path: '../html2rss'
 # gem 'html2rss-configs', path: '../html2rss-configs'
 
 gem 'concurrent-ruby'

Gemfile.lock

@@ -5,6 +5,29 @@ GIT
     html2rss-configs (0.2.0)
       html2rss
 
+PATH
+  remote: ../html2rss
+  specs:
+    html2rss (0.19.1)
+      addressable (~> 2.7)
+      brotli
+      dry-validation
+      faraday (> 2.0.1, < 3.0)
+      faraday-follow_redirects
+      faraday-gzip (~> 3)
+      kramdown
+      mime-types (> 3.0)
+      nokogiri (>= 1.10, < 2.0)
+      parallel
+      puppeteer-ruby
+      regexp_parser
+      reverse_markdown (~> 3.0)
+      rss
+      sanitize
+      thor
+      tzinfo
+      zeitwerk
+
 GEM
   remote: https://rubygems.org/
   specs:
@@ -136,25 +159,6 @@ GEM
       fiber-storage
     fiber-storage (1.0.1)
     hashdiff (1.2.1)
-    html2rss (0.19.1)
-      addressable (~> 2.7)
-      brotli
-      dry-validation
-      faraday (> 2.0.1, < 3.0)
-      faraday-follow_redirects
-      faraday-gzip (~> 3)
-      kramdown
-      mime-types (> 3.0)
-      nokogiri (>= 1.10, < 2.0)
-      parallel
-      puppeteer-ruby
-      regexp_parser
-      reverse_markdown (~> 3.0)
-      rss
-      sanitize
-      thor
-      tzinfo
-      zeitwerk
     i18n (1.14.8)
       concurrent-ruby (~> 1.0)
     io-console (0.8.2)
@@ -371,7 +375,7 @@ PLATFORMS
 DEPENDENCIES
   climate_control
   concurrent-ruby
-  html2rss (~> 0.19)
+  html2rss!
   html2rss-configs!
   irb
   parallel
@@ -439,7 +443,7 @@ CHECKSUMS
   fiber-local (1.1.0) sha256=c885f94f210fb9b05737de65d511136ea602e00c5105953748aa0f8793489f06
   fiber-storage (1.0.1) sha256=f48e5b6d8b0be96dac486332b55cee82240057065dc761c1ea692b2e719240e1
   hashdiff (1.2.1) sha256=9c079dbc513dfc8833ab59c0c2d8f230fa28499cc5efb4b8dd276cf931457cd1
-  html2rss (0.19.1) sha256=0af89c99421eb45ad386885cd4e9d946fbb1a887e757922c6f6bc5d825a32ac2
+  html2rss (0.19.1)
   html2rss-configs (0.2.0)
   i18n (1.14.8) sha256=285778639134865c5e0f6269e0b818256017e8cde89993fdfcbfb64d088824a5
   io-console (0.8.2) sha256=d6e3ae7a7cc7574f4b8893b4fca2162e57a825b223a177b7afa236c5ef9814cc

app/web/boot/setup.rb

@@ -23,11 +23,21 @@ def call!
             configure_sentry!
             configure_request_service!
             configure_runtime_logging!
+            configure_gem_defaults!
             log_startup!
           end
 
           private
 
+          # @return [void]
+          def configure_gem_defaults!
+            global_config = LocalConfig.global
+            Html2rss.configure do |config|
+              config.headers = global_config[:headers] if global_config[:headers]
+              config.stylesheets = global_config[:stylesheets] if global_config[:stylesheets]
+            end
+          end
+
           # @return [void]
           def validate_environment!
             EnvironmentValidator.validate_environment!

app/web/config/local_config.rb

@@ -42,7 +42,7 @@ def find(name)
           config_hash = local_feed_config(normalized_name) || embedded_feed_config(normalized_name)
           raise NotFound, "Did not find local feed config at '#{normalized_name}'" unless config_hash
 
-          apply_global_defaults(config_hash)
+          config_hash
         end
 
         ##
@@ -120,19 +120,6 @@ def embedded_feed_config(normalized_name)
           nil
         end
 
-        # Applies global defaults only when feed-level keys are absent.
-        #
-        # @param config [Hash{Symbol=>Object}]
-        # @return [Hash{Symbol=>Object}]
-        def apply_global_defaults(config)
-          global_config = global
-
-          config[:stylesheets] ||= deep_dup(global_config[:stylesheets]) if global_config[:stylesheets]
-          config[:headers] ||= deep_dup(global_config[:headers]) if global_config[:headers]
-
-          config
-        end
-
         # @param name [String, Symbol, #to_s]
         # @return [String] path without feed extension for feed lookup.
         def normalize_name(name)

app/web/rendering/xml_builder.rb

@@ -1,7 +1,8 @@
 # frozen_string_literal: true
 
-require 'nokogiri'
+require 'rss'
 require 'time'
+
 module Html2rss
   module Web
     ##
@@ -18,17 +19,11 @@ class << self
         # @param timestamp [Time, nil]
         # @return [String] serialized RSS XML document.
         def build_rss_feed(title:, description:, link: nil, items: [], timestamp: nil)
-          current_time = timestamp || Time.now
-          formatted_now = format_pub_date(current_time)
-
-          Nokogiri::XML::Builder.new(encoding: 'UTF-8') do |xml|
-            xml.rss(version: '2.0') do
-              xml.channel do
-                build_channel(xml, title:, description:, link:, now: formatted_now)
-                build_items(xml, items, default_pub_date: formatted_now)
-              end
-            end
-          end.doc.to_xml(save_with: Nokogiri::XML::Node::SaveOptions::AS_XML)
+          RSS::Maker.make('2.0') do |maker|
+            apply_stylesheets(maker)
+            build_channel(maker.channel, title:, description:, link:, timestamp:)
+            build_items(maker, items, default_timestamp: timestamp)
+          end.to_s
         end
 
         # @param message [String]
@@ -61,6 +56,16 @@ def build_empty_feed_warning(url:, strategy:, site_title: nil)
 
         private
 
+        # @param maker [RSS::Maker::RSS20]
+        # @return [void]
+        def apply_stylesheets(maker)
+          # Use the gem's internal stylesheet support.
+          stylesheets = Html2rss.configuration.stylesheets.map do |s|
+            Html2rss::RssBuilder::Stylesheet.new(**s)
+          end
+          Html2rss::RssBuilder::Stylesheet.add(maker, stylesheets)
+        end
+
         # @param title [String]
         # @param description [String]
         # @param item [Hash{Symbol=>Object}]
@@ -81,57 +86,43 @@ def build_single_item_feed(title:, description:, item:, link: nil)
         # @param timestamp [Time]
         # @return [Hash{Symbol=>Object}] normalized item with required RSS fields.
         def feed_item(item, timestamp:)
-          feed_item = {
+          {
             title: item[:title],
             description: item[:description],
+            link: item[:link],
             pubDate: timestamp
           }
-          feed_item[:link] = item[:link] if item[:link]
-          feed_item
         end
 
-        # @param xml [Nokogiri::XML::Builder]
+        # @param channel [RSS::Maker::RSS20::Channel]
         # @param title [String]
         # @param description [String]
         # @param link [String, nil]
-        # @param now [String]
+        # @param timestamp [Time, nil]
         # @return [void]
-        def build_channel(xml, title:, description:, link:, now:)
-          xml.title(title.to_s)
-          xml.description(description.to_s)
-          xml.link(link.to_s) if link
-          xml.lastBuildDate(now)
-          xml.pubDate(now)
+        def build_channel(channel, title:, description:, link:, timestamp:)
+          now = timestamp || Time.now
+          channel.title = title.to_s
+          channel.description = description.to_s
+          channel.link = link.to_s
+          channel.lastBuildDate = now
+          channel.pubDate = now
         end
 
-        # @param xml [Nokogiri::XML::Builder]
+        # @param maker [RSS::Maker::RSS20]
         # @param items [Array<Hash{Symbol=>Object}>]
-        # @param default_pub_date [String]
+        # @param default_timestamp [Time, nil]
         # @return [void]
-        def build_items(xml, items, default_pub_date:)
+        def build_items(maker, items, default_timestamp:)
           items.each do |item|
-            xml.item do
-              append_text_node(xml, :title, item[:title])
-              append_text_node(xml, :description, item[:description])
-              append_text_node(xml, :link, item[:link])
-              xml.pubDate(format_pub_date(item[:pubDate] || default_pub_date))
+            maker.items.new_item do |i|
+              i.title = item[:title].to_s
+              i.description = item[:description].to_s
+              i.link = item[:link].to_s
+              i.pubDate = item[:pubDate] || default_timestamp || Time.now
             end
           end
         end
-
-        # @param xml [Nokogiri::XML::Builder]
-        # @param node_name [Symbol]
-        # @param value [Object]
-        # @return [void]
-        def append_text_node(xml, node_name, value)
-          xml.public_send(node_name, value.to_s) if value
-        end
-
-        # @param pub_date [Time, String]
-        # @return [String] RFC2822 date string for RSS output.
-        def format_pub_date(pub_date)
-          pub_date.is_a?(Time) ? pub_date.rfc2822 : pub_date.to_s
-        end
       end
     end
   end

spec/html2rss/web/xml_builder_spec.rb

@@ -29,5 +29,9 @@
     it 'does not mention hidden strategy controls in item text' do
       expect(xml_doc.at_xpath('//item/description').text).not_to include('browserless strategy')
     end
+
+    it 'includes the default stylesheet processing instruction' do
+      expect(xml_doc.to_s).to include('<?xml-stylesheet href="/rss.xsl" type="text/xsl" media="all"?>')
+    end
   end
 end