index.js

/**
 * Beautify Pug(former jade) file.
 *
 * var pugBeautify = require('pug-beautify');
 * var beautifiedString = pugBeautify-beautify(code,{fill_tab:true,omit_div:false,tab_size:4});
 *
 * @param  {string} code - strings to be beautified.
 * @param  {Object} opt - options.
 * @param  {boolean} opt.fill_tab - fill whether tab or space, default true.
 * @param  {boolean} opt.omit_div - whether omit 'div' tag, default false.
 * @param  {number} opt.tab_size - when 'fill_tab' is false, fill 'tab_size' spaces, default 4.
 * @param  {boolean} opt.separator_space - When 'separator_space' is true, the attribute separator is comma, default true.
 * @param  {boolean} opt.omit_empty_lines - When 'separator_space' is false, delete line blank, default true.
 * @return {string} code - strings beautified.
 */

module.exports = function(code, opt) {
  'use strict';

  opt = (typeof opt === 'undefined') ? {} : opt;
  if (typeof code !== 'string') quit('Code must be a string text.');
  if (typeof opt !== 'undefined' && typeof opt !== 'object') quit('Option must be a object.');

  var fill_tab = (typeof opt.fill_tab !== 'undefined') ? opt.fill_tab : true;
  var omit_div = (typeof opt.omit_div !== 'undefined') ? opt.omit_div : false;
  var tab_size = (typeof opt.tab_size !== 'undefined') ? opt.tab_size : 4;
  var separator = opt.separator_space ? ' ' : ', ';
  var empty_lines = (typeof opt.omit_empty_lines !== 'undefined') ? opt.omit_empty_lines : true;
  var debug = (typeof opt.debug !== 'undefined') ? opt.debug : false;

  if (debug) console.log(fill_tab, omit_div, tab_size, debug, separator);

  // list of indents
  var indentList = [];

  var prevIndent = {
    type: 'code', // type 'code' or 'remark'
    indent: 0, // count of indent space. it replace tab with space
    tab: 0, // count of tab ,line indent will be filled up with this value.
    input: '', // input line after removing indent.
  };

  if (!empty_lines) {
    code = code.replace(/^\s*[\r\n]/gm, '');
  }

  var lines = code.split('\n');

  lines.forEach(function(line, n) { // array.forEach is blocking, no async function.
    // it return matching space --> data[0], data[index] = 0, remained input --> data.input
    var data = line.match(/^\s*/);

    // when tab and space mixed, it replace all tab to spaces.
    var tmp = data[0].replace(/\t/g, Array(tab_size + 1).join(' '));
    var remainedInput = data.input.replace(/^\s*/, '');
    var indent = (remainedInput.length === 0) ? 0 : tmp.length;

    var tab = 0;
    var type = (remainedInput.match(/^\/\/|^\/\*|^\*/)) ? 'remark' : 'code';

    if (omit_div) {
      remainedInput = remainedInput.replace(/^div(\.|#)/i, '$1');
    }

    if (indent === 0) {
      tab = 0;
    } else {
      // when this line & prev line is 'remark', it fallow prev line tab.
      if (indentList.length > 0 && type === 'remark' && indentList[indentList.length - 1].type === 'remark') {
        tab = prevIndent.tab;
      } else {
        if (indent === prevIndent.indent) { // when same indent, follow prev tab.
          tab = prevIndent.tab;
        } else if (indent > prevIndent.indent) { // when indented, add tab
          tab = prevIndent.tab + 1;
        } else { // when new indent, if find the same indent, and follow it's tab.
          for (var i = indentList.length - 1; i >= 0; i--) {
            if (indent == indentList[i].indent) {
              tab = indentList[i].tab;
              break;
            }
          }
        }
      }
    }
    if (debug) console.log(n + 1, indent, tab, prevIndent.indent);

    if (remainedInput.match(/\w+\(.+(,|\s).*\)/)) {
      if (debug) console.log('antes =>', remainedInput);
      if (remainedInput.match(/\w+=('|").+('|")\s?,\s/)) {
        remainedInput = remainedInput.replace(/('|")(,\s+)(([\w-]+=("|'))|$)/g, '$1' + separator + '$4');
        if (debug) console.log('new(' + separator + ')=>', remainedInput);
      }
    }

    var curIndent = {
      type: type,
      indent: indent,
      tab: tab,
      input: remainedInput,
    };

    indentList.push(curIndent);

    if (remainedInput.length !== 0) { // discard null line
      prevIndent = curIndent;
    }
  });

  // // Here,it reformat with it's tab count.
  var formatedLine = indentList.map(function(line, n) {
    var space = Array(line.tab + 1).join('\t');
    //when fill with space
    if (!fill_tab) space = space.replace(/\t/g, Array(tab_size + 1).join(' '));

    if (debug) console.log(n + 1, line.indent, line.tab, space + line.input);
    return space + line.input;
  });

  //Rewrite data
  return formatedLine.join('\n');
};

function quit(reason) {
  throw new Error(reason);
}