Class: Riff

Inherits:
Object
  • Object
show all
Includes:
Colors
Defined in:
lib/riff.rb

Overview

Call do_stream() with the output of some diff-like tool (diff, diff3, git diff, …) and it will highlight that output for you.

rubocop:disable Metrics/ClassLength

Constant Summary collapse

DIFF_HEADER = 
/^diff /
DIFF_HUNK_HEADER = 
/^@@ /
DIFF_ADDED = 
/^\+(.*)/
DIFF_REMOVED = 
/^-(.*)/
DIFF_CONTEXT = 
/^ /
DIFF_NO_ENDING_NEWLINE = 
/^\\/
LINE_PREFIX = 
{
  initial:          '',
  diff_header:      BOLD,
  diff_hunk_header: CYAN,
  diff_hunk:        '',
  diff_added:       GREEN,
  diff_removed:     RED,
  diff_context:     '',
  diff_no_ending_newline: ''
}

Constants included from Colors

Colors::BOLD, Colors::CYAN, Colors::DEFAULT_COLOR, Colors::ESC, Colors::GREEN, Colors::NOT_REVERSE, Colors::RED, Colors::RESET, Colors::REVERSE

Instance Method Summary collapse

Methods included from Colors

#reversed, #uncolor

Constructor Details

#initialize ⇒ Riff

Returns a new instance of Riff.



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# File 'lib/riff.rb', line 31

def initialize()
  @state = :initial

  @replace_old = ''
  @replace_new = ''
end

Instance Method Details

#consume_replacement ⇒ Object

If we have stored adds / removes, calling this method will flush those.



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# File 'lib/riff.rb', line 108

def consume_replacement()
  return '' if @replace_old.empty? && @replace_new.empty?

  refiner = Refiner.new(@replace_old, @replace_new)
  return_me = refiner.refined_old
  return_me += refiner.refined_new

  @replace_old = ''
  @replace_new = ''

  return return_me
end

#do_stream(diff_stream) ⇒ Object

Read diff from a stream and output a highlighted version to stdout



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# File 'lib/riff.rb', line 155

def do_stream(diff_stream)
  output = ''
  current_line = nil

  begin
    diff_stream.each do |line|
      current_line = line
      output += handle_diff_line(line)
    end
    output += consume_replacement()
  rescue
    STDERR.puts "State: <#{@state}>"
    STDERR.puts "Current line: <#{current_line}>"
    raise
  end

  return output
end

#handle_diff_added_line(line) ⇒ Object 



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# File 'lib/riff.rb', line 90

def handle_diff_added_line(line)
  handle_diff_hunk_line(line)
end

#handle_diff_context_line(line) ⇒ Object 



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# File 'lib/riff.rb', line 98

def handle_diff_context_line(line)
  handle_diff_hunk_line(line)
end

#handle_diff_header_line(line) ⇒ Object 



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# File 'lib/riff.rb', line 44

def handle_diff_header_line(line)
  if line =~ DIFF_HUNK_HEADER
    @state = :diff_hunk_header
  end
end

#handle_diff_hunk_header_line(line) ⇒ Object 



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# File 'lib/riff.rb', line 50

def handle_diff_hunk_header_line(line)
  handle_diff_hunk_line(line)
end

#handle_diff_hunk_line(line) ⇒ Object 



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# File 'lib/riff.rb', line 71

def handle_diff_hunk_line(line)
  case line
  when DIFF_HUNK_HEADER
    @state = :diff_hunk_header
  when DIFF_HEADER
    @state = :diff_header
  when DIFF_ADDED
    @state = :diff_added
  when DIFF_REMOVED
    @state = :diff_removed
  when DIFF_CONTEXT
    @state = :diff_context
  when DIFF_NO_ENDING_NEWLINE
    handle_no_ending_newline(line)
  else
    fail NotImplementedError, "Can't handle <#{@state}> line: <#{line}>"
  end
end

#handle_diff_line(line) ⇒ Object 



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# File 'lib/riff.rb', line 130

def handle_diff_line(line)
  line.chomp!
  line = uncolor(line)

  handle_line_for_state(@state, line)

  case @state
  when :diff_added
    @replace_new += DIFF_ADDED.match(line)[1] + "\n"
    return ''
  when :diff_removed
    @replace_old += DIFF_REMOVED.match(line)[1] + "\n"
    return ''
  when :diff_no_ending_newline
    return ''
  else
    refined = consume_replacement()

    color = LINE_PREFIX.fetch(@state)

    return refined + DiffString.decorate_string('', color, line + "\n")
  end
end

#handle_diff_no_ending_newline_line(line) ⇒ Object 



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# File 'lib/riff.rb', line 102

def handle_diff_no_ending_newline_line(line)
  handle_diff_hunk_line(line)
end

#handle_diff_removed_line(line) ⇒ Object 



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# File 'lib/riff.rb', line 94

def handle_diff_removed_line(line)
  handle_diff_hunk_line(line)
end

#handle_initial_line(line) ⇒ Object 



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# File 'lib/riff.rb', line 38

def handle_initial_line(line)
  if line =~ DIFF_HEADER
    @state = :diff_header
  end
end

#handle_line_for_state(state, line) ⇒ Object

Call handle_<state>_line() for the given state and line



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# File 'lib/riff.rb', line 122

def handle_line_for_state(state, line)
  method_name = "handle_#{state}_line"
  fail "Unknown state: <:#{state}>" unless
    self.respond_to? method_name

  send(method_name, line)
end

#handle_no_ending_newline(line) ⇒ Object 



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# File 'lib/riff.rb', line 54

def handle_no_ending_newline(line)
  case @state
  when :diff_added
    @replace_new.sub!(/\n$/, '')
  when :diff_removed
    @replace_old.sub!(/\n$/, '')
  when :diff_context
    # Intentionally ignored
    return
  else
    fail NotImplementedError,
         "Can't handle no-ending-newline in <#{@state}> line: <#{line}>"
  end

  @state = :diff_no_ending_newline
end