var fs = require('fs');

function readLines(input, func) {
  var remaining = '';
  const words = [];

  input.on('data', function(data) {
    remaining += data;
    var index = remaining.indexOf('\n');
    var last  = 0;
    while (index > -1) {
      var line = remaining.substring(last, index);
      last = index + 1;
      words.push(line);
      index = remaining.indexOf('\n', last);
    }

    remaining = remaining.substring(last);
  });

  input.on('end', function() {
    if (remaining.length > 0) {
      words.push(remaining);
    }

    func(words);
  });
}

function func(data) {
   fs.writeFileSync('words.json', JSON.stringify(data), 'utf8');
}

var input = fs.createReadStream('wordlist.txt');
readLines(input, func);