resolves #3641 add support for inline linenums mode when using Rouge as source highlighter (PR #4129)

6 files changed, 72 insertions, 25 deletions

diff --git a/CHANGELOG.adoc b/CHANGELOG.adoc
index da662c24..9f9f7495 100644
--- a/CHANGELOG.adoc
+++ b/CHANGELOG.adoc
@@ -17,6 +17,10 @@ This project utilizes semantic versioning.
 
 == Unreleased
 
+Enhancements::
+
+  * Add support for inline linenums mode when using Rouge as source highlighter (`rouge-linenums-mode=inline`) (#3641)
+
 Bug Fixes::
 
   * Remove unnamespaced selectors in Pygments stylesheet
diff --git a/data/stylesheets/asciidoctor-default.css b/data/stylesheets/asciidoctor-default.css
index 1a65da65..7b34860a 100644
--- a/data/stylesheets/asciidoctor-default.css
+++ b/data/stylesheets/asciidoctor-default.css
@@ -225,8 +225,8 @@ pre.prettyprint li:not(:first-child) code[data-lang]::before{display:none}
 table.linenotable{border-collapse:separate;border:0;margin-bottom:0;background:none}
 table.linenotable td[class]{color:inherit;vertical-align:top;padding:0;line-height:inherit;white-space:normal}
 table.linenotable td.code{padding-left:.75em}
-table.linenotable td.linenos,pre.pygments .linenos{border-right:1px solid;opacity:.35;padding-right:.5em}
-pre.pygments span.linenos{display:inline-block;margin-right:.75em}
+table.linenotable td.linenos,pre.pygments .linenos,pre.rouge .linenos{border-right:1px solid;opacity:.35;padding-right:.5em}
+pre.pygments span.linenos,pre.rouge span.linenos{display:inline-block;margin-right:.75em}
 .quoteblock{margin:0 1em 1.25em 1.5em;display:table}
 .quoteblock:not(.excerpt)>.title{margin-left:-1.5em;margin-bottom:.75em}
 .quoteblock blockquote,.quoteblock p{color:rgba(0,0,0,.85);font-size:1.15rem;line-height:1.75;word-spacing:.1em;letter-spacing:0;font-style:italic;text-align:justify}
diff --git a/lib/asciidoctor/rouge_ext.rb b/lib/asciidoctor/rouge_ext.rb
index 57a65d1b..96339beb 100644
--- a/lib/asciidoctor/rouge_ext.rb
+++ b/lib/asciidoctor/rouge_ext.rb
@@ -5,40 +5,56 @@ require 'rouge' unless defined? Rouge.version
 module Asciidoctor
 module RougeExt
   module Formatters
-    class HTMLTable < ::Rouge::Formatter
+    class HTMLLineHighlighter < ::Rouge::Formatter
+      def initialize delegate, opts
+        @delegate = delegate
+        @lines = opts[:lines] || []
+      end
+
+      def stream tokens
+        if @lines.empty?
+          token_lines(tokens) {|tokens_in_line| yield (@delegate.format tokens_in_line) + LF }
+        else
+          (token_lines tokens).with_index 1 do |tokens_in_line, lineno|
+            formatted_line = (@delegate.format tokens_in_line) + LF
+            yield (@lines.include? lineno) ? %(<span class="hll">#{formatted_line}</span>) : formatted_line
+          end
+        end
+      end
+    end
+
+    class HTMLLineNumberer < ::Rouge::Formatter
       def initialize delegate, opts
         @delegate = delegate
         @start_line = opts[:start_line] || 1
       end
 
       def stream tokens
-        formatted_code = @delegate.format tokens
-        formatted_code += LF unless formatted_code.end_with? LF, HangingEndSpanTagCs
-        last_lineno = (first_lineno = @start_line) + (formatted_code.count LF) - 1 # assume number of newlines is constant
-        lineno_format = %(%#{(::Math.log10 last_lineno).floor + 1}i)
-        formatted_linenos = ((first_lineno..last_lineno).map {|lineno| sprintf lineno_format, lineno } << '').join LF
-        yield %(<table class="linenotable"><tbody><tr><td class="linenos gl"><pre class="lineno">#{formatted_linenos}</pre></td><td class="code"><pre>#{formatted_code}</pre></td></tr></tbody></table>)
+        formatted_lines = (@delegate.to_enum :stream, tokens).map.with_index(@start_line) {|line, lineno| [lineno.to_s, line] }
+        return unless (last_lineno = (formatted_lines[-1] || [])[0])
+        lineno_width = last_lineno.length
+        formatted_lines.each {|(lineno, line)| yield %(<span class="linenos">#{lineno.rjust lineno_width}</span>#{line}) }
       end
     end
 
-    class HTMLLineHighlighter < ::Rouge::Formatter
+    class HTMLTableLineNumberer < ::Rouge::Formatter
       def initialize delegate, opts
         @delegate = delegate
-        @lines = opts[:lines] || []
+        @start_line = opts[:start_line] || 1
       end
 
       def stream tokens
-        (token_lines tokens).with_index 1 do |tokens_in_line, lineno|
-          formatted_line = (@delegate.format tokens_in_line) + LF
-          yield (@lines.include? lineno) ? %(<span class="hll">#{formatted_line}</span>) : formatted_line
-        end
+        formatted_lines = (@delegate.to_enum :stream, tokens).with_index(@start_line).with_object({}) {|(line, lineno), accum| accum[lineno.to_s] = line }
+        return unless (last_lineno = formatted_lines.keys[-1])
+        lineno_width = last_lineno.length
+        formatted_linenos = formatted_lines.keys.map {|lineno| (lineno.rjust lineno_width) + LF }
+        yield %(<table class="linenotable"><tbody><tr><td class="linenos gl"><pre class="lineno">#{formatted_linenos.join}</pre></td><td class="code"><pre>#{formatted_lines.values.join}</pre></td></tr></tbody></table>)
       end
     end
 
     LF = ?\n
-    HangingEndSpanTagCs = %(#{LF}</span>)
 
-    private_constant :HangingEndSpanTagCs, :LF
+    private_constant :LF
   end
 end
 end
diff --git a/lib/asciidoctor/syntax_highlighter/rouge.rb b/lib/asciidoctor/syntax_highlighter/rouge.rb
index d483a307..3709e4f6 100644
--- a/lib/asciidoctor/syntax_highlighter/rouge.rb
+++ b/lib/asciidoctor/syntax_highlighter/rouge.rb
@@ -76,10 +76,16 @@ class SyntaxHighlighter::RougeAdapter < SyntaxHighlighter::Base
     formatter = opts[:css_mode] == :class ?
       (::Rouge::Formatters::HTML.new inline_theme: @style) :
       (::Rouge::Formatters::HTMLInline.new (::Rouge::Theme.find @style).new)
-    if (highlight_lines = opts[:highlight_lines])
-      formatter = RougeExt::Formatters::HTMLLineHighlighter.new formatter, lines: highlight_lines
+    if (number_lines = opts[:number_lines])
+      formatter = RougeExt::Formatters::HTMLLineHighlighter.new formatter, lines: opts[:highlight_lines]
+      number_lines == :table ?
+        (RougeExt::Formatters::HTMLTableLineNumberer.new formatter, start_line: opts[:start_line_number]) :
+        (RougeExt::Formatters::HTMLLineNumberer.new formatter, start_line: opts[:start_line_number])
+    elsif (highlight_lines = opts[:highlight_lines])
+      RougeExt::Formatters::HTMLLineHighlighter.new formatter, lines: highlight_lines
+    else
+      formatter
     end
-    opts[:number_lines] ? (RougeExt::Formatters::HTMLTable.new formatter, start_line: opts[:start_line_number]) : formatter
   end
 
   module Loader
diff --git a/src/stylesheets/asciidoctor.css b/src/stylesheets/asciidoctor.css
index 9d86f8f8..6bf43cb4 100644
--- a/src/stylesheets/asciidoctor.css
+++ b/src/stylesheets/asciidoctor.css
@@ -1400,13 +1400,15 @@ table.linenotable td.code {
 }
 
 table.linenotable td.linenos,
-pre.pygments .linenos {
+pre.pygments .linenos,
+pre.rouge .linenos {
   border-right: 1px solid;
   opacity: 0.35;
   padding-right: 0.5em;
 }
 
-pre.pygments span.linenos {
+pre.pygments span.linenos,
+pre.rouge span.linenos {
   display: inline-block;
   margin-right: 0.75em;
 }
diff --git a/test/syntax_highlighter_test.rb b/test/syntax_highlighter_test.rb
index adb5064e..eafbf6ea 100644
--- a/test/syntax_highlighter_test.rb
+++ b/test/syntax_highlighter_test.rb
@@ -809,12 +809,12 @@ context 'Syntax Highlighter' do
       assert_css 'code span.gp', output, 1
     end
 
-    test 'should set starting line number to 1 by default in HTML output if linenums option is enabled' do
+    test 'should number lines using table layout if linenums option is enabled and linenums mode is not set' do
       input = <<~'EOS'
       [source%linenums,ruby]
       ----
-      puts 'Hello, World!'
-      puts 'Goodbye, World!'
+      puts 'Hello, world!'
+      puts 'Goodbye, world!'
       ----
       EOS
       output = convert_string_to_embedded input, attributes: { 'source-highlighter' => 'rouge' }
@@ -826,6 +826,25 @@ context 'Syntax Highlighter' do
       assert_xpath %(//pre[@class="lineno"][text()="1\n2\n"]), output, 1
     end
 
+    test 'should number lines using inline element if linenums option is enabled and linenums mode is inline' do
+      input = <<~'EOS'
+      :rouge-linenums-mode: inline
+
+      [source%linenums,ruby]
+      ----
+      puts 'Hello, world!'
+      puts 'Goodbye, world!'
+      ----
+      EOS
+      expected = <<~EOS.chop
+      <span class="linenos">1</span><span class="nb">puts</span> <span class="s1">'Hello, world!'</span>
+      <span class="linenos">2</span><span class="nb">puts</span> <span class="s1">'Goodbye, world!'</span>
+      EOS
+      output = convert_string_to_embedded input, attributes: { 'source-highlighter' => 'rouge' }
+      assert_css 'table.linenotable', output, 0
+      assert_includes output, expected
+    end
+
     test 'should set starting line number in HTML output if linenums option is enabled and start attribute is set' do
       input = <<~'EOS'
       [source%linenums,ruby,start=9]