Feature.terminal truecolor

lib/rouge.rb

@@ -72,6 +72,7 @@ def lexer_dir(path = '')
 load_relative 'rouge/formatters/html_line_table'
 load_relative 'rouge/formatters/html_inline'
 load_relative 'rouge/formatters/terminal256'
+load_relative 'rouge/formatters/terminal_truecolor'
 load_relative 'rouge/formatters/tex'
 load_relative 'rouge/formatters/null'
 

lib/rouge/cli.rb

@@ -4,6 +4,8 @@
 # not required by the main lib.
 # to use this module, require 'rouge/cli'.
 
+require 'rbconfig'
+
 module Rouge
   class FileReader
     attr_reader :input
@@ -200,9 +202,22 @@ def self.doc
         yield %[                            delimiters. implies --escape]
       end
 
+      # There is no consistent way to do this, but this is used elsewhere,
+      # and we provide explicit opt-in and opt-out with $COLORTERM
+      def self.supports_truecolor?
+        return true if %w(24bit truecolor).include?(ENV['COLORTERM'])
+        return false if ENV['COLORTERM'] && ENV['COLORTERM'] =~ /256/
+
+        if RbConfig::CONFIG['host_os'] =~ /mswin|mingw/
+          ENV['ConEmuANSI'] == 'ON' && !ENV['ANSICON']
+        else
+          ENV['TERM'] !~ /(^rxvt)|(-color$)/
+        end
+      end
+
       def self.parse(argv)
         opts = {
-          :formatter => 'terminal256',
+          :formatter => supports_truecolor? ? 'terminal-truecolor' : 'terminal256',
           :theme => 'thankful_eyes',
           :css_class => 'codehilite',
           :input_file => '-',
@@ -299,8 +314,10 @@ def initialize(opts={})
 
         theme = Theme.find(opts[:theme]).new or error! "unknown theme #{opts[:theme]}"
 
+        # TODO: document this in --help
         @formatter = case opts[:formatter]
         when 'terminal256' then Formatters::Terminal256.new(theme)
+        when 'terminal-truecolor' then Formatters::TerminalTruecolor.new(theme)
         when 'html' then Formatters::HTML.new
         when 'html-pygments' then Formatters::HTMLPygments.new(Formatters::HTML.new, opts[:css_class])
         when 'html-inline' then Formatters::HTMLInline.new(theme)

lib/rouge/formatters/terminal256.rb

@@ -174,7 +174,11 @@ def escape_sequence(token)
         return Unescape.new if escape?(token)
         @escape_sequences ||= {}
         @escape_sequences[token.qualname] ||=
-          EscapeSequence.new(get_style(token))
+          make_escape_sequence(get_style(token))
+      end
+
+      def make_escape_sequence(style)
+        EscapeSequence.new(style)
       end
 
       def get_style(token)

lib/rouge/formatters/terminal_truecolor.rb

@@ -0,0 +1,37 @@
+# -*- coding: utf-8 -*- #
+# frozen_string_literal: true
+module Rouge
+  module Formatters
+    class TerminalTruecolor < Terminal256
+      tag 'terminal_truecolor'
+
+      class TruecolorEscapeSequence < Terminal256::EscapeSequence
+        def style_string
+          @style_string ||= begin
+            out = String.new('')
+            out << escape(['48', '2', *get_rgb(style.bg)]) if style.bg
+            out << escape(['38', '2', *get_rgb(style.fg)]) if style.fg
+            out << escape(['1']) if style[:bold] || style[:italic]
+            out
+          end
+        end
+
+        def get_rgb(color)
+          color = $1 if color =~ /#(\h+)/
+
+          case color.size
+          when 3 then color.chars.map { |c| c.to_i(16) * 2 }
+          when 6 then color.scan(/../).map { |cc| cc.to_i(16) }
+          else
+            raise "invalid color: #{color.inspect}"
+          end
+        end
+      end
+
+      # @override
+      def make_escape_sequence(style)
+        TruecolorEscapeSequence.new(style)
+      end
+    end
+  end
+end

spec/formatters/terminal_truecolor_spec.rb

@@ -0,0 +1,12 @@
+# -*- coding: utf-8 -*- #
+# frozen_string_literal: true
+
+describe Rouge::Formatters::TerminalTruecolor do
+  let(:subject) { Rouge::Formatters::TerminalTruecolor.new }
+
+  it 'renders a thing' do
+    result = subject.format([[Token['Text'], 'foo']])
+
+    assert { result == "\e[38;2;250;246;228mfoo\e[39m" }
+  end
+end