commentwrap.js

var reLeadingDot = /^\./;
var slashStarComments = {
  leading: '/*',
  line:    ' * ',
  end:     ' */ '
};
var fileComments = {
  js: slashStarComments,
  css: slashStarComments,
  coffee: {
    leading: '###',
    line:    '',
    end:     '###'
  }
};
var reLineBreak = /\r?\n/;

// intialise line endings based on platform
var lineEnding = process.platform == 'win32' ? '\r\n' : '\n';

module.exports = function(opts, content) {
  // split the content on line breaks
  var lines = [''].concat((content || '').split(reLineBreak)).concat('');
  var lastLineIdx = lines.length - 1;
  var filetype = (opts.filetype || 'js').replace(reLeadingDot, '');
  var comments;

  // get the comments for the specific filetype
  comments = fileComments[filetype] || slashStarComments;
  
  // if we have a leader then add an additional line for a tidy output
  if (opts.leader) {
    lines.unshift('');
  }
  
  // iterate through the lines and add the comments
  lines = lines.map(function(line, index) {
    var comment = comments[index === 0 ? 'leading' : 'line'];
    
    // if we are at the first line, then add the optional leader
    if (index === 0) {
      comment += (opts.leader || '');
    }

    // add the comment line to the content line
    return comment + line;
  }).concat(comments.end);

  // wrap in the comments
  return lines.join(lineEnding);
};