Class: Byebug::SourceFileFormatter

Inherits:
Object
  • Object
show all
Defined in:
lib/convenient_service/dependencies/extractions/byebug_syntax_highlighting.rb

Instance Method Summary collapse

Instance Method Details

#file ⇒ Object

This is a replacement of the internal Byebug::SourceFileFormatter.file method which adds syntax highlighting capability to it.

The original implementation simply returns the file path which is passed to the Byebug::SourceFileFormatter constructor just as file. (See github.com/deivid-rodriguez/byebug/blob/master/lib/byebug/source_file_formatter.rb#L13)

The current replacement, instead of returning the original file path, returns a copy of it, where the syntax is highlighted by the Rouge gem(A pure Ruby code highlighter). (See github.com/rouge-ruby/rouge)

In order to create a copy, it utilizes Ruby’s tempfile stdlib. (See ruby-doc.org/stdlib-2.7.0/libdoc/tempfile/rdoc/Tempfile.html) A tempfile is automatically deleted from the underlying OS when it is garbage-collected.



30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
 
# File 'lib/convenient_service/dependencies/extractions/byebug_syntax_highlighting.rb', line 30

def file
  @highlighted_file ||=
    begin
      if defined? Rouge
        source = File.read(@file)

        theme     = Rouge::Themes::Monokai.new
        formatter = Rouge::Formatters::Terminal256.new(theme)
        lexer     = Rouge::Lexers::Ruby.new

        dest = formatter.format(lexer.lex(source))

        # Tempfile with the highlighted syntax is assigned to the instance variable
        # in order to prevent its premature garbage collection.
        @tempfile_with_highlighted_syntax = Tempfile.new.tap { |t| t.write(dest) }.tap(&:close)

        @tempfile_with_highlighted_syntax.path
      else
        warn %q{Rouge(a pure Ruby code highlighter) is not defined. Maybe you forgot to require it? (require 'rouge')}

        @file
      end
    end
end