rubocop: reduce code complexity and remove duplicated code

.rubocop.yml

@@ -4,7 +4,6 @@ AllCops:
   Include:
     - lib/**/*.rb
   Exclude:
-    - lib/jekyll/renderer.rb
     - bin/**/*
     - exe/**/*
     - benchmark/**/*

lib/jekyll/convertible.rb

@@ -78,7 +78,7 @@ module Jekyll
     #
     # Returns the transformed contents.
     def transform
-      _renderer.transform
+      _renderer.convert(content)
     end
 
     # Determine the extension depending on content_type.

lib/jekyll/page.rb

@@ -127,12 +127,12 @@ module Jekyll
     # layouts      - The Hash of {"name" => "layout"}.
     # site_payload - The site payload Hash.
     #
-    # Returns nothing.
+    # Returns String rendered page.
     def render(layouts, site_payload)
-      site_payload["page"] = to_liquid
+      self.output = _renderer.tap do |renderer|
-      site_payload["paginator"] = pager.to_liquid
+        renderer.layouts = layouts
-
+        renderer.payload = site_payload
-      do_layout(site_payload, layouts)
+      end.run
     end
 
     # The path to the source file

lib/jekyll/renderer.rb

@@ -33,50 +33,44 @@ module Jekyll
     # Determine which converters to use based on this document's
     # extension.
     #
-    # Returns an array of Converter instances.
+    # Returns Array of Converter instances.
     def converters
       @converters ||= site.converters.select { |c| c.matches(document.extname) }.sort
     end
 
     # Determine the extname the outputted file should have
     #
-    # Returns the output extname including the leading period.
+    # Returns String the output extname including the leading period.
     def output_ext
       @output_ext ||= (permalink_ext || converter_output_ext)
     end
 
-    ######################
+    # Prepare payload and render the document
-    ## DAT RENDER THO
+    #
-    ######################
+    # Returns String rendered document output
-
     def run
       Jekyll.logger.debug "Rendering:", document.relative_path
 
-      payload["page"] = document.to_liquid
+      assign_pages!
-
+      assign_related_posts!
-      if document.respond_to? :pager
+      assign_highlighter_options!
-        payload["paginator"] = document.pager.to_liquid
-      end
-
-      if document.is_a?(Document) && document.collection.label == "posts"
-        payload["site"]["related_posts"] = document.related_posts
-      else
-        payload["site"]["related_posts"] = nil
-      end
-
-      # render and transform content (this becomes the final content of the object)
-      payload["highlighter_prefix"] = converters.first.highlighter_prefix
-      payload["highlighter_suffix"] = converters.first.highlighter_suffix
 
       Jekyll.logger.debug "Pre-Render Hooks:", document.relative_path
       document.trigger_hooks(:pre_render, payload)
 
+      render_document
+    end
+
+    # Render the document.
+    #
+    # Returns String rendered document output
+    # rubocop: disable AbcSize
+    def render_document
       info = {
+        :filters   => [Jekyll::Filters],
         :registers => { :site => site, :page => payload["page"] }
       }
-
       output = document.content
-
       if document.render_with_liquid?
         Jekyll.logger.debug "Rendering Liquid:", document.relative_path
         output = render_liquid(output, payload, info, document.path)
@@ -88,21 +82,16 @@ module Jekyll
 
       if document.place_in_layout?
         Jekyll.logger.debug "Rendering Layout:", document.relative_path
-        place_in_layouts(
+        output = place_in_layouts(output, payload, info)
-          output,
-          payload,
-          info
-        )
-      else
-        output
       end
-    end
 
-    # Convert the given content using the converters which match this renderer's document.
+      output
+    end
+    # rubocop: enable AbcSize
+
+    # Convert the document using the converters which match this renderer's document.
     #
-    # content - the raw, unconverted content
+    # Returns String the converted content.
-    #
-    # Returns the converted content.
     def convert(content)
       converters.reduce(content) do |output, converter|
         begin
@@ -124,7 +113,7 @@ module Jekyll
     # info    -
     # path    - (optional) the path to the file, for use in ex
     #
-    # Returns the content, rendered by Liquid.
+    # Returns String the content, rendered by Liquid.
     def render_liquid(content, payload, info, path = nil)
       template = site.liquid_renderer.file(path).parse(content)
       template.warnings.each do |e|
@@ -144,26 +133,18 @@ module Jekyll
     #
     # layout - the layout to check
     #
-    # Returns true if the layout is invalid, false if otherwise
+    # Returns Boolean true if the layout is invalid, false if otherwise
     def invalid_layout?(layout)
       !document.data["layout"].nil? && layout.nil? && !(document.is_a? Jekyll::Excerpt)
     end
 
-    # Render layouts and place given content inside.
+    # Render layouts and place document content inside.
     #
-    # content - the content to be placed in the layout
+    # Returns String rendered content
-    #
-    #
-    # Returns the content placed in the Liquid-rendered layouts
     def place_in_layouts(content, payload, info)
       output = content.dup
       layout = layouts[document.data["layout"]]
-
+      validate_layout(layout)
-      Jekyll.logger.warn(
-        "Build Warning:",
-        "Layout '#{document.data["layout"]}' requested in "\
-        "#{document.relative_path} does not exist."
-      ) if invalid_layout? layout
 
       used = Set.new([layout])
 
@@ -171,33 +152,87 @@ module Jekyll
       payload["layout"] = nil
 
       while layout
-        payload["content"] = output
+        output = render_layout(output, layout, info)
-        payload["layout"]  = Utils.deep_merge_hashes(layout.data, payload["layout"] || {})
+        add_regenerator_dependencies(layout)
 
-        output = render_liquid(
+        if (layout = site.layouts[layout.data["layout"]])
-          layout.content,
-          payload,
-          info,
-          layout.relative_path
-        )
-
-        # Add layout to dependency tree
-        site.regenerator.add_dependency(
-          site.in_source_dir(document.path),
-          site.in_source_dir(layout.path)
-        ) if document.write?
-
-        if (layout = layouts[layout.data["layout"]])
           break if used.include?(layout)
           used << layout
         end
       end
-
       output
     end
 
+    # Checks if the layout specified in the document actually exists
+    #
+    # layout - the layout to check
+    # Returns nothing
     private
+    def validate_layout(layout)
+      Jekyll.logger.warn(
+        "Build Warning:",
+        "Layout '#{document.data["layout"]}' requested "\
+        "in #{document.relative_path} does not exist."
+      ) if invalid_layout?(layout)
+    end
 
+    # Render layout content into document.output
+    #
+    # Returns String rendered content
+    private
+    def render_layout(output, layout, info)
+      payload["content"] = output
+      payload["layout"]  = Utils.deep_merge_hashes(layout.data, payload["layout"] || {})
+
+      render_liquid(
+        layout.content,
+        payload,
+        info,
+        layout.relative_path
+      )
+    end
+
+    private
+    def add_regenerator_dependencies(layout)
+      site.regenerator.add_dependency(
+        site.in_source_dir(document.path),
+        site.in_source_dir(layout.path)
+      ) if document.write?
+    end
+
+    # Set page content to payload and assign pager if document has one.
+    #
+    # Returns nothing
+    private
+    def assign_pages!
+      payload["page"] = document.to_liquid
+      payload["paginator"] = if document.respond_to?(:pager)
+                               document.pager.to_liquid
+                             end
+    end
+
+    # Set related posts to payload if document is a post.
+    #
+    # Returns nothing
+    private
+    def assign_related_posts!
+      if document.is_a?(Document) && document.collection.label == "posts"
+        payload["site"]["related_posts"] = document.related_posts
+      else
+        payload["site"]["related_posts"] = nil
+      end
+    end
+
+    # Set highlighter prefix and suffix
+    #
+    # Returns nothing
+    private
+    def assign_highlighter_options!
+      payload["highlighter_prefix"] = converters.first.highlighter_prefix
+      payload["highlighter_suffix"] = converters.first.highlighter_suffix
+    end
+
+    private
     def permalink_ext
       if document.permalink && !document.permalink.end_with?("/")
         permalink_ext = File.extname(document.permalink)
@@ -205,6 +240,7 @@ module Jekyll
       end
     end
 
+    private
     def converter_output_ext
       if output_exts.size == 1
         output_exts.last
@@ -213,6 +249,7 @@ module Jekyll
       end
     end
 
+    private
     def output_exts
       @output_exts ||= converters.map do |c|
         c.output_ext(document.extname)