beautify.js

/*jslint adsafe: false, bitwise: true, browser: true, cap: false, css: false,
  debug: false, devel: true, eqeqeq: true, es5: false, evil: false,
  forin: false, fragment: false, immed: true, laxbreak: false, newcap: true,
  nomen: false, on: false, onevar: true, passfail: false, plusplus: true,
  regexp: false, rhino: true, safe: false, strict: false, sub: false,
  undef: true, white: false, widget: false, windows: false */
/*global exports: false */
"use strict";

/*

 JS Beautifier
---------------


  Written by Einar Lielmanis, <einar@jsbeautifier.org>
      http://jsbeautifier.org/

  Originally converted to javascript by Vital, <vital76@gmail.com>

  You are free to use this in any way you want, in case you find this useful or working for you.

  Usage:
    js_beautify(js_source_text);
    js_beautify(js_source_text, options);

  The options are:
    indent_size (default 4)          — indentation size,
    indent_char (default space)      — character to indent with,
    preserve_newlines (default true) — whether existing line breaks should be preserved,
    indent_level (default 0)         — initial indentation level, you probably won't need this ever,

    space_after_anon_function (default false) — if true, then space is added between "function ()"
            (jslint is happy about this); if false, then the common "function()" output is used.
    braces_on_own_line (default false) - ANSI / Allman brace style, each opening/closing brace gets its own line.

    e.g

    js_beautify(js_source_text, {indent_size: 1, indent_char: '\t'});


*/



function js_beautify(js_source_text, options) {

  options = options ? options : {};

  var input,
    output,
    token_text,
    last_type,
    last_text,
    last_last_text,
    last_word,
    flags,
    flag_store,
    indent_string,
    whitespace,
    wordchar,
    punct,
    parser_pos,
    line_starters,
    digits,
    prefix,
    token_type,
    do_block_just_closed,
    wanted_newline,
    just_added_newline = false,
    n_newlines,
    opt_braces_on_own_line = options.braces_on_own_line ? options.braces_on_own_line : false,
    opt_indent_size = options.indent_size ? options.indent_size : 4,
    opt_indent_char = options.indent_char ? options.indent_char : ' ',
    opt_preserve_newlines = typeof options.preserve_newlines === 'undefined' ? true : options.preserve_newlines,
    opt_indent_level = options.indent_level ? options.indent_level : 0, // starting indentation
    opt_space_after_anon_function = options.space_after_anon_function === 'undefined' ? false : options.space_after_anon_function,
    opt_keep_array_indentation = typeof options.keep_array_indentation === 'undefined' ? false : options.keep_array_indentation,
    input_length = js_source_text.length,
    space_before = true,
    space_after = true,
    t,
    i,
    lines;


  function trim_output() {
    while (output.length && (output[output.length - 1] === ' ' || output[output.length - 1] === indent_string)) {
      output.pop();
    }
  }
  

  function is_array(mode) {
    return mode === '[EXPRESSION]' || mode === '[INDENTED-EXPRESSION]';
  }


  function print_newline(ignore_repeated) {
    flags.eat_next_space = false;
    if (opt_keep_array_indentation && is_array(flags.mode)) {
      return;
    }

    ignore_repeated = typeof ignore_repeated === 'undefined' ? true : ignore_repeated;

    flags.if_line = false;
    trim_output();

    if (!output.length) {
      return; // no newline on start of file
    }

    if (output[output.length - 1] !== "\n" || !ignore_repeated) {
      just_added_newline = true;
      output.push("\n");
    }
    
    for (var i = 0; i < flags.indentation_level; i += 1) {
      output.push(indent_string);
    }
    
    if (flags.var_line && flags.var_line_reindented) {
      if (opt_indent_char === ' ') {
        output.push('    '); // var_line always pushes 4 spaces, so that the variables would be one under another
      }
      else {
        output.push(indent_string); // skip space-stuffing, if indenting with a tab
      }
    }
  }


  function print_single_space() {
    var last_output = ' ';

    if (flags.eat_next_space) {
      flags.eat_next_space = false;
      return;
    }

    if (output.length) {
      last_output = output[output.length - 1];
    }

    if (last_output !== ' ' && last_output !== '\n' && last_output !== indent_string) { // prevent occassional duplicate space
      output.push(' ');
    }
  }


  function print_token() {
    just_added_newline = false;
    flags.eat_next_space = false;
    output.push(token_text);
  }
  

  function indent() {
    flags.indentation_level += 1;
  }


  function remove_indent() {
    if (output.length && output[output.length - 1] === indent_string) {
      output.pop();
    }
  }


  function set_mode(mode) {
    if (flags) {
      flag_store.push(flags);
    }

    flags = {
      previous_mode: flags ? flags.mode : 'BLOCK',
      mode: mode,
      var_line: false,
      var_line_tainted: false,
      var_line_reindented: false,
      in_html_comment: false,
      if_line: false,
      in_case: false,
      eat_next_space: false,
      indentation_baseline: -1,
      indentation_level: (flags ? flags.indentation_level + ((flags.var_line && flags.var_line_reindented) ? 1 : 0) : opt_indent_level)
    };
  }


  function is_expression(mode) {
    return mode === '[EXPRESSION]' || mode === '[INDENTED-EXPRESSION]' || mode === '(EXPRESSION)';
  }
  

  function restore_mode() {
    do_block_just_closed = flags.mode === 'DO_BLOCK';
    if (flag_store.length > 0) {
      flags = flag_store.pop();
    }
  }


  function in_array(what, arr) {
    for (var i = 0; i < arr.length; i += 1) {
      if (arr[i] === what) {
        return true;
      }
    }
    return false;
  }


  // Walk backwards from the colon to find a '?' (colon is part of a ternary op)
  // or a '{' (colon is part of a class literal).  Along the way, keep track of
  // the blocks and expressions we pass so we only trigger on those chars in our
  // own level, and keep track of the colons so we only trigger on the matching '?'.

  function is_ternary_op() {
    var level = 0,
      colon_count = 0,
      i;
        
    for (i = output.length - 1; i >= 0; i -= 1) {
      switch (output[i]) {
      case ':':
        if (level === 0) {
          colon_count += 1;
        }
        break;
        
      case '?':
        if (level === 0) {
          if (colon_count === 0) {
            return true;
          } else {
            colon_count -= 1;
          }
        }
        break;
        
      case '{':
        if (level === 0) {
          return false;
        }
        level -= 1;
        break;
        
      case '(':
      case '[':
        level -= 1;
        break;
        
      case ')':
      case ']':
      case '}':
        level += 1;
        break;
      }
    }
  }
  

  function get_next_token() {
    var c,
      keep_whitespace = opt_keep_array_indentation && is_array(flags.mode),
      whitespace_count = 0,
      i,
      sign,
      t,
      comment,
      inline_comment,
      sep,
      esc,
      resulting_string,
      in_char_class,
      sharp;
    
    n_newlines = 0;

    if (parser_pos >= input_length) {
      return ['', 'TK_EOF'];
    }

    wanted_newline = false;

    c = input.charAt(parser_pos);
    parser_pos += 1;

    if (keep_whitespace) {
      //
      // slight mess to allow nice preservation of array indentation and reindent that correctly
      // first time when we get to the arrays:
      // var a = [
      // ....'something'
      // we make note of whitespace_count = 4 into flags.indentation_baseline
      // so we know that 4 whitespaces in original source match indent_level of reindented source
      //
      // and afterwards, when we get to
      //    'something,
      // .......'something else'
      // we know that this should be indented to indent_level + (7 - indentation_baseline) spaces
      //

      while (in_array(c, whitespace)) {
        if (c === "\n") {
          trim_output();
          output.push("\n");
          just_added_newline = true;
          whitespace_count = 0;
        }
        else {
          if (c === '\t') {
            whitespace_count += 4;
          }
          else {
            whitespace_count += 1;
          }
        }

        if (parser_pos >= input_length) {
          return ['', 'TK_EOF'];
        }

        c = input.charAt(parser_pos);
        parser_pos += 1;
      }

      if (flags.indentation_baseline === -1) {
        flags.indentation_baseline = whitespace_count;
      }

      if (just_added_newline) {
        for (i = 0; i < flags.indentation_level + 1; i += 1) {
          output.push(indent_string);
        }
        
        if (flags.indentation_baseline !== -1) {
          for (i = 0; i < whitespace_count - flags.indentation_baseline; i += 1) {
            output.push(' ');
          }
        }
      }

    }
    else {
      while (in_array(c, whitespace)) {
        if (c === "\n") {
          n_newlines += 1;
        }

        if (parser_pos >= input_length) {
          return ['', 'TK_EOF'];
        }

        c = input.charAt(parser_pos);
        parser_pos += 1;
      }

      if (opt_preserve_newlines) {
        if (n_newlines > 1) {
          for (i = 0; i < n_newlines; i += 1) {
            print_newline(i === 0);
            just_added_newline = true;
          }
        }
      }
      wanted_newline = n_newlines > 0;
    }

    if (in_array(c, wordchar)) {
      if (parser_pos < input_length) {
        while (in_array(input.charAt(parser_pos), wordchar)) {
          c += input.charAt(parser_pos);
          parser_pos += 1;
          
          if (parser_pos === input_length) {
            break;
          }
        }
      }

      // small and surprisingly unugly hack for 1E-10 representation
      if (parser_pos !== input_length && c.match(/^[0-9]+[Ee]$/) && (input.charAt(parser_pos) === '-' || input.charAt(parser_pos) === '+')) {

        sign = input.charAt(parser_pos);
        parser_pos += 1;

        t = get_next_token(parser_pos);
        c += sign + t[0];
        
        return [c, 'TK_WORD'];
      }

      if (c === 'in') { // hack for 'in' operator
        return [c, 'TK_OPERATOR'];
      }
      
      if (wanted_newline && last_type !== 'TK_OPERATOR' && !flags.if_line && (opt_preserve_newlines || last_text !== 'var')) {
        print_newline();
      }
      
      return [c, 'TK_WORD'];
    }

    if (c === '(' || c === '[') {
      return [c, 'TK_START_EXPR'];
    }

    if (c === ')' || c === ']') {
      return [c, 'TK_END_EXPR'];
    }

    if (c === '{') {
      return [c, 'TK_START_BLOCK'];
    }

    if (c === '}') {
      return [c, 'TK_END_BLOCK'];
    }

    if (c === ';') {
      return [c, 'TK_SEMICOLON'];
    }

    if (c === '/') {
      // peek for comment /* ... */
      inline_comment = true;
      comment = '';
      
      if (input.charAt(parser_pos) === '*') {
        parser_pos += 1;
        if (parser_pos < input_length) {
          while (!(input.charAt(parser_pos) === '*' && input.charAt(parser_pos + 1) && input.charAt(parser_pos + 1) === '/') && parser_pos < input_length) {
            c = input.charAt(parser_pos);
            comment += c;

            if (c === '\x0d' || c === '\x0a') {
              inline_comment = false;
            }

            parser_pos += 1;

            if (parser_pos >= input_length) {
              break;
            }
          }
        }

        parser_pos += 2;

        if (inline_comment) {
          return ['/*' + comment + '*/', 'TK_INLINE_COMMENT'];
        }
        else {
          return ['/*' + comment + '*/', 'TK_BLOCK_COMMENT'];
        }
      }
      // peek for comment // ...
      if (input.charAt(parser_pos) === '/') {
        comment = c;
        while (input.charAt(parser_pos) !== "\x0d" && input.charAt(parser_pos) !== "\x0a") {
          comment += input.charAt(parser_pos);
          parser_pos += 1;

          if (parser_pos >= input_length) {
            break;
          }
        }

        parser_pos += 1;

        if (wanted_newline) {
          print_newline();
        }

        return [comment, 'TK_COMMENT'];
      }
    }

    if (c === "'" || // string
      c === '"' || // string
      (c === '/' && ((last_type === 'TK_WORD' && in_array(last_text, ['return', 'do'])) || (last_type === 'TK_START_EXPR' || last_type === 'TK_START_BLOCK' || last_type === 'TK_END_BLOCK' || last_type === 'TK_OPERATOR' || last_type === 'TK_EQUALS' || last_type === 'TK_EOF' || last_type === 'TK_SEMICOLON'))))
    { // regexp

      sep = c;
      esc = false;
      resulting_string = c;

      if (parser_pos < input_length) {
        if (sep === '/') {
          // handle regexp separately...
          in_char_class = false;

          while (esc || in_char_class || input.charAt(parser_pos) !== sep) {
            resulting_string += input.charAt(parser_pos);

            if (!esc) {
              esc = input.charAt(parser_pos) === '\\';

              if (input.charAt(parser_pos) === '[') {
                in_char_class = true;
              }
              else if (input.charAt(parser_pos) === ']') {
                in_char_class = false;
              }
            }
            else {
              esc = false;
            }
            
            parser_pos += 1;
            
            if (parser_pos >= input_length) {
              // incomplete string/rexp when end-of-file reached.
              // bail out with what had been received so far.
              return [resulting_string, 'TK_STRING'];
            }
          }
        }
        else {
          // and handle string also separately
          while (esc || input.charAt(parser_pos) !== sep) {
            resulting_string += input.charAt(parser_pos);

            if (!esc) {
              esc = input.charAt(parser_pos) === '\\';
            }
            else {
              esc = false;
            }
            
            parser_pos += 1;
            
            if (parser_pos >= input_length) {
              // incomplete string/rexp when end-of-file reached.
              // bail out with what had been received so far.
              return [resulting_string, 'TK_STRING'];
            }
          }
        }
      }

      parser_pos += 1;
      resulting_string += sep;

      if (sep === '/') {
        // regexps may have modifiers /regexp/MOD , so fetch those, too
        while (parser_pos < input_length && in_array(input.charAt(parser_pos), wordchar)) {
          resulting_string += input.charAt(parser_pos);
          parser_pos += 1;
        }
      }
      
      return [resulting_string, 'TK_STRING'];
    }

    if (c === '#') {
      // Spidermonkey-specific sharp variables for circular references
      // https://developer.mozilla.org/En/Sharp_variables_in_JavaScript
      // http://mxr.mozilla.org/mozilla-central/source/js/src/jsscan.cpp around line 1935
      sharp = '#';
      
      if (parser_pos < input_length && in_array(input.charAt(parser_pos), digits)) {
        do {
          c = input.charAt(parser_pos);
          sharp += c;
          parser_pos += 1;
        } while (parser_pos < input_length && c !== '#' && c !== '=');
        
        if (c === '#') {
          //
        }
        else if (input.charAt(parser_pos) === '[' && input.charAt(parser_pos + 1) === ']') {
          sharp += '[]';
          parser_pos += 2;
        }
        else if (input.charAt(parser_pos) === '{' && input.charAt(parser_pos + 1) === '}') {
          sharp += '{}';
          parser_pos += 2;
        }
        
        return [sharp, 'TK_WORD'];
      }
    }

    if (c === '<' && input.substring(parser_pos - 1, parser_pos + 3) === '<!--') {
      parser_pos += 3;
      flags.in_html_comment = true;
      return ['<!--', 'TK_COMMENT'];
    }

    if (c === '-' && flags.in_html_comment && input.substring(parser_pos - 1, parser_pos + 2) === '-->') {
      flags.in_html_comment = false;
      parser_pos += 2;
      
      if (wanted_newline) {
        print_newline();
      }
      
      return ['-->', 'TK_COMMENT'];
    }

    if (in_array(c, punct)) {
      while (parser_pos < input_length && in_array(c + input.charAt(parser_pos), punct)) {
        c += input.charAt(parser_pos);
        parser_pos += 1;
        if (parser_pos >= input_length) {
          break;
        }
      }

      if (c === '=') {
        return [c, 'TK_EQUALS'];
      } else {
        return [c, 'TK_OPERATOR'];
      }
    }

    return [c, 'TK_UNKNOWN'];
  }
  // END get_next_token()
  

  //----------------------------------
  
  
  indent_string = '';
  
  while (opt_indent_size > 0) {
    indent_string += opt_indent_char;
    opt_indent_size -= 1;
  }

  input = js_source_text;
  last_word = ''; // last 'TK_WORD' passed
  last_type = 'TK_START_EXPR'; // last token type
  last_text = ''; // last token text
  last_last_text = ''; // pre-last token text
  output = [];

  do_block_just_closed = false;

  whitespace = "\n\r\t ".split('');
  wordchar = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789_$'.split('');
  digits = '0123456789'.split('');
  punct = '+ - * / % & ++ -- = += -= *= /= %= == === != !== > < >= <= >> << >>> >>>= >>= <<= && &= | || ! !! , : ? ^ ^= |= ::'.split(' ');

  // words which should always start on new line.
  line_starters = 'continue,try,throw,return,var,if,switch,case,default,for,while,break,function'.split(',');

  // states showing if we are currently in expression (i.e. "if" case) - 'EXPRESSION', or in usual block (like, procedure), 'BLOCK'.
  // some formatting depends on that.
  flag_store = [];
  set_mode('BLOCK');

  parser_pos = 0;
  while (true) {
    t = get_next_token(parser_pos);
    token_text = t[0];
    token_type = t[1];
    if (token_type === 'TK_EOF') {
      break;
    }

    switch (token_type) {

      case 'TK_START_EXPR':
        if (token_text === '[') {

          if (last_type === 'TK_WORD' || last_text === ')') {
            // this is array index specifier, break immediately
            // a[x], fn()[x]
            if (in_array(last_text, line_starters)) {
              print_single_space();
            }
          
            set_mode('(EXPRESSION)');
            print_token();
            break;
          }

          if (flags.mode === '[EXPRESSION]' || flags.mode === '[INDENTED-EXPRESSION]') {
            if (last_last_text === ']' && last_text === ',') {
              // ], [ goes to new line
              if (flags.mode === '[EXPRESSION]') {
                flags.mode = '[INDENTED-EXPRESSION]';

                if (!opt_keep_array_indentation) {
                  indent();
                }
              }
            
              set_mode('[EXPRESSION]');
            
              if (!opt_keep_array_indentation) {
                print_newline();
              }
            }
            else if (last_text === '[') {
              if (flags.mode === '[EXPRESSION]') {
                flags.mode = '[INDENTED-EXPRESSION]';
                if (!opt_keep_array_indentation) {
                  indent();
                }
              }
              set_mode('[EXPRESSION]');

              if (!opt_keep_array_indentation) {
                print_newline();
              }
            }
            else {
              set_mode('[EXPRESSION]');
            }
          }
          else {
            set_mode('[EXPRESSION]');
          }
        }
        else {
          set_mode('(EXPRESSION)');
        }

        if (last_text === ';' || last_type === 'TK_START_BLOCK') {
          print_newline();
        }
        else if (last_type === 'TK_END_EXPR' || last_type === 'TK_START_EXPR' || last_type === 'TK_END_BLOCK' || last_text === '.') {
          // do nothing on (( and )( and ][ and ]( and .(
        }
        else if (last_type !== 'TK_WORD' && last_type !== 'TK_OPERATOR') {
          print_single_space();
        }
        else if (last_word === 'function') {
          // function() vs function ()
          if (opt_space_after_anon_function) {
            print_single_space();
          }
        }
        else if (in_array(last_text, line_starters) || last_text === 'catch') {
          print_single_space();
        }
      
        print_token();
        break;

      case 'TK_END_EXPR':
        if (token_text === ']') {
          if (opt_keep_array_indentation) {
            if (last_text === '}') {
              // trim_output();
              // print_newline(true);
              remove_indent();
              print_token();
              restore_mode();
              break;
            }
          }
          else {
            if (flags.mode === '[INDENTED-EXPRESSION]') {
              if (last_text === ']') {
                restore_mode();
                print_newline();
                print_token();
                break;
              }
            }
          }
        }
        restore_mode();
        print_token();
        break;

      case 'TK_START_BLOCK':
        if (last_word === 'do') {
          set_mode('DO_BLOCK');
        }
        else {
          set_mode('BLOCK');
        }
      
        if (opt_braces_on_own_line) {
          if (last_type !== 'TK_OPERATOR') {
            if (last_text === 'return') {
              print_single_space();
            }
            else {
              print_newline(true);
            }
          }
        
          print_token();
          indent();
        }
        else {
          if (last_type !== 'TK_OPERATOR' && last_type !== 'TK_START_EXPR') {
            if (last_type === 'TK_START_BLOCK') {
              print_newline();
            }
            else {
              print_single_space();
            }
          }
          else {
            // if TK_OPERATOR or TK_START_EXPR
            if (is_array(flags.previous_mode) && last_text === ',') {
              print_newline(); // [a, b, c, {
            }
          }
          indent();
          print_token();
        }

        break;

      case 'TK_END_BLOCK':
        restore_mode();
      
        if (opt_braces_on_own_line) {
          print_newline();
          print_token();
        }
        else {
          if (last_type === 'TK_START_BLOCK') {
            // nothing
            if (just_added_newline) {
              remove_indent();
            }
            else {
              // {}
              trim_output();
            }
          }
          else {
            print_newline();
          }

          print_token();
        }
        break;

      case 'TK_WORD':
        // no, it's not you. even I have problems understanding how this works
        // and what does what.
        if (do_block_just_closed) {
          // do {} ## while ()
          print_single_space();
          print_token();
          print_single_space();
          do_block_just_closed = false;
          break;
        }

        if (token_text === 'function') {
          if ((just_added_newline || last_text === ';') && last_text !== '{') {
            // make sure there is a nice clean space of at least one blank line
            // before a new function definition
            n_newlines = just_added_newline ? n_newlines : 0;

            for (i = 0; i < 2 - n_newlines; i += 1) {
              print_newline(false);
            }
          }
        }

        if (token_text === 'case' || token_text === 'default') {
          if (last_text === ':') {
            // switch cases following one another
            remove_indent();
          }
          else {
            // case statement starts in the same line where switch
            flags.indentation_level -= 1;
            print_newline();
            flags.indentation_level += 1;
          }
        
          print_token();
          flags.in_case = true;
          break;
        }

        prefix = 'NONE';

        if (last_type === 'TK_END_BLOCK') {
          if (!in_array(token_text.toLowerCase(), ['else', 'catch', 'finally'])) {
            prefix = 'NEWLINE';
          }
          else {
            if (opt_braces_on_own_line) {
              prefix = 'NEWLINE';
            }
            else {
              prefix = 'SPACE';
              print_single_space();
            }
          }
        }
        else if (last_type === 'TK_SEMICOLON' && (flags.mode === 'BLOCK' || flags.mode === 'DO_BLOCK')) {
          prefix = 'NEWLINE';
        }
        else if (last_type === 'TK_SEMICOLON' && is_expression(flags.mode)) {
          prefix = 'SPACE';
        }
        else if (last_type === 'TK_STRING') {
          prefix = 'NEWLINE';
        }
        else if (last_type === 'TK_WORD') {
          prefix = 'SPACE';
        }
        else if (last_type === 'TK_START_BLOCK') {
          prefix = 'NEWLINE';
        }
        else if (last_type === 'TK_END_EXPR') {
          print_single_space();
          prefix = 'NEWLINE';
        }

        if (last_type !== 'TK_END_BLOCK' && in_array(token_text.toLowerCase(), ['else', 'catch', 'finally'])) {
          print_newline();
        }
        else if (in_array(token_text, line_starters) || prefix === 'NEWLINE') {
          if (last_text === 'else') {
            // no need to force newline on else break
            print_single_space();
          }
          else if ((last_type === 'TK_START_EXPR' || last_text === '=' || last_text === ',') && token_text === 'function') {
            // no need to force newline on 'function': (function
            // DONOTHING
          }
          else if (last_text === 'return' || last_text === 'throw') {
            // no newline between 'return nnn'
            print_single_space();
          }
          else if (last_type !== 'TK_END_EXPR') {
            if ((last_type !== 'TK_START_EXPR' || token_text !== 'var') && last_text !== ':') {
              // no need to force newline on 'var': for (var x = 0...)
              if (token_text === 'if' && last_word === 'else' && last_text !== '{') {
                // no newline for } else if {
                print_single_space();
              }
              else {
                print_newline();
              }
            }
          }
          else {
            if (in_array(token_text, line_starters) && last_text !== ')') {
              print_newline();
            }
          }
        }
        else if (is_array(flags.mode) && last_text === ',' && last_last_text === '}') {
          print_newline(); // }, in lists get a newline treatment
        }
        else if (prefix === 'SPACE') {
          print_single_space();
        }
      
        print_token();
        last_word = token_text;

        if (token_text === 'var') {
          flags.var_line = true;
          flags.var_line_reindented = false;
          flags.var_line_tainted = false;
        }

        if (token_text === 'if' || token_text === 'else') {
          flags.if_line = true;
        }

        break;

      case 'TK_SEMICOLON':
        print_token();
        flags.var_line = false;
        flags.var_line_reindented = false;
        break;

      case 'TK_STRING':
        if (last_type === 'TK_START_BLOCK' || last_type === 'TK_END_BLOCK' || last_type === 'TK_SEMICOLON') {
          print_newline();
        }
        else if (last_type === 'TK_WORD') {
          print_single_space();
        }
      
        print_token();
        break;

      case 'TK_EQUALS':
        if (flags.var_line) {
          // just got an '=' in a var-line, different formatting/line-breaking, etc will now be done
          flags.var_line_tainted = true;
        }
      
        print_single_space();
        print_token();
        print_single_space();
        break;

      case 'TK_OPERATOR':
        space_before = true;
        space_after = true;

        if (flags.var_line && token_text === ',' && (is_expression(flags.mode))) {
          // do not break on comma, for(var a = 1, b = 2)
          flags.var_line_tainted = false;
        }

        if (flags.var_line) {
          if (token_text === ',') {
            if (flags.var_line_tainted) {
              print_token();
              flags.var_line_reindented = true;
              flags.var_line_tainted = false;
              print_newline();
              break;
            }
            else {
              flags.var_line_tainted = false;
            }
            // } else if (token_text === ':') {
            // hmm, when does this happen? tests don't catch this
            // flags.var_line = false;
          }
        }

        if (last_text === 'return' || last_text === 'throw') {
          // "return" had a special handling in TK_WORD. Now we need to return the favor
          print_single_space();
          print_token();
          break;
        }

        if (token_text === ':' && flags.in_case) {
          print_token(); // colon really asks for separate treatment
          print_newline();
          flags.in_case = false;
          break;
        }

        if (token_text === '::') {
          // no spaces around exotic namespacing syntax operator
          print_token();
          break;
        }

        if (token_text === ',') {
          if (flags.var_line) {
            if (flags.var_line_tainted) {
              print_token();
              print_newline();
              flags.var_line_tainted = false;
            }
            else {
              print_token();
              print_single_space();
            }
          }
          else if (last_type === 'TK_END_BLOCK' && flags.mode !== "(EXPRESSION)") {
            print_token();
            if (flags.mode === 'OBJECT' && last_text === '}') {
              print_newline();
            } else {
              print_single_space();
            }
          }
          else {
            if (flags.mode === 'OBJECT') {
              print_token();
              print_newline();
            }
            else {
              // EXPR or DO_BLOCK
              print_token();
              print_single_space();
            }
          }
          break;
          // } else if (in_array(token_text, ['--', '++', '!']) || (in_array(token_text, ['-', '+']) && (in_array(last_type, ['TK_START_BLOCK', 'TK_START_EXPR', 'TK_EQUALS']) || in_array(last_text, line_starters) || in_array(last_text, ['==', '!=', '+=', '-=', '*=', '/=', '+', '-'])))) {
        }
        else if (in_array(token_text, ['--', '++', '!']) || (in_array(token_text, ['-', '+']) && (in_array(last_type, ['TK_START_BLOCK', 'TK_START_EXPR', 'TK_EQUALS', 'TK_OPERATOR']) || in_array(last_text, line_starters)))) {
          // unary operators (and binary +/- pretending to be unary) special cases
          space_before = false;
          space_after = false;

          if (last_text === ';' && is_expression(flags.mode)) {
            // for (;; ++i)
            //        ^^^
            space_before = true;
          }
        
          if (last_type === 'TK_WORD' && in_array(last_text, line_starters)) {
            space_before = true;
          }

          if (flags.mode === 'BLOCK' && (last_text === '{' || last_text === ';')) {
            // { foo; --i }
            // foo(); --bar;
            print_newline();
          }
        }
        else if (token_text === '.') {
          // decimal digits or object.property
          space_before = false;

        }
        else if (token_text === ':') {
          if (!is_ternary_op()) {
            flags.mode = 'OBJECT';
            space_before = false;
          }
        }
      
        if (space_before) {
          print_single_space();
        }

        print_token();

        if (space_after) {
          print_single_space();
        }

        if (token_text === '!') {
          // flags.eat_next_space = true;
        }

        break;

      case 'TK_BLOCK_COMMENT':
        lines = token_text.split(/\x0a|\x0d\x0a/);

        if (/^\/\*\*/.test(token_text)) {
          // javadoc: reformat and reindent
          print_newline();
          output.push(lines[0]);
        
          for (i = 1; i < lines.length; i += 1) {
            print_newline();
            output.push(' ');
            output.push(lines[i].replace(/^\s\s*|\s\s*$/, ''));
          }
        }
        else {
          // simple block comment: leave intact
          if (lines.length > 1) {
            // multiline comment block starts with a new line
            print_newline();
            trim_output();
          }
          else {
            // single-line /* comment */ stays where it is
            print_single_space();
          }
        
          for (i = 0; i < lines.length; i += 1) {
            output.push(lines[i]);
            output.push('\n');
          }
        }

        print_newline();
        break;

      case 'TK_INLINE_COMMENT':
        print_single_space();
        print_token();
        if (is_expression(flags.mode)) {
          print_single_space();
        } else {
          print_newline();
        }
        break;

      case 'TK_COMMENT':
        // print_newline();
        if (wanted_newline) {
          print_newline();
        } else {
          print_single_space();
        }
        print_token();
        print_newline();
        break;

      case 'TK_UNKNOWN':
        print_token();
        break;
    }

    last_last_text = last_text;
    last_type = token_type;
    last_text = token_text;
  }

  return output.join('').replace(/[\n ]+$/, '');
}

// Add support for CommonJS. Just put this file somewhere on your require.paths
// and you will be able to `var js_beautify = require("beautify").js_beautify`.
if (typeof exports !== "undefined") {
  exports.js_beautify = js_beautify;
}