class RuboCop::Cop::Style::Tab

This cop checks for tabs inside the source code.

def autocorrect(range) 

def autocorrect(range)
  @corrections << lambda do |corrector|
    corrector.replace(range, range.source.gsub(/\t/, '  '))
  end
end

def investigate(processed_source) 

def investigate(processed_source)
  processed_source.lines.each_with_index do |line, index|
    match = line.match(/^( *)[\t ]*\t/)
    next unless match
    spaces = match.captures[0]
    range = source_range(processed_source.buffer,
                         index + 1,
                         (spaces.length)...(match.end(0)))
    add_offense(range, range, MSG)
  end
end