Obfuscate JavaScript code into having zero readable characters; I want to improve this not to use eval at all but I'll have to write a JS tokenizer for that.

obfuscator.js

const zero = '+[]'; // 1
const one = '+!![]'; // 1
const two = '('+ one + one +')'; // 2
const three = '('+ one + one + one +')'; // 3
const four = '('+ one + one + '<<' + one +')'; // 3
const five = '('+ four + one +')'; // 4
const six = '('+ one + one + one + '<<' + one +')'; // 4
const seven = '('+ six + one +')';
const eight = '('+ one + one + '<<' + one + one +')'; // 4
const int_lits = {0: zero, 1: one, 2: two, 3: three, 4: four, 5: five, 6: six, 7: seven, 8: eight};

function compile_int(n) {
  if (n in int_lits) return int_lits[n];
  let compiled = [], m = n;
  if (n < 0) m = -n;
  const stack = m.toString(8).split('');

  for (let sh = 0; stack.length > 0; sh++) {
    const lit = parseInt(stack.pop());
    if (lit === 0) continue;
    let tentative = int_lits[lit];
    if (sh > 0) tentative = '('+tentative+'<<'+compile_int(sh*3)+')';
    compiled.push(tentative);
  }

  compiled = '('+compiled.join('|')+')';
  if (n < 0) compiled = '-'+compiled;
  int_lits[n] = compiled;
  return compiled;
}

const char_lits = {
  'N': '(+{}+[])['+compile_int(0)+']',
  'a': '(+{}+[])['+compile_int(1)+']',
  // N
  '[': '({}+[])['+compile_int(0)+']',
  'o': '({}+[])['+compile_int(1)+']',
  'b': '({}+[])['+compile_int(2)+']',
  'j': '({}+[])['+compile_int(3)+']',
  // e
  'c': '({}+[])['+compile_int(5)+']',
  // t
  ' ': '({}+[])['+compile_int(7)+']',
  'O': '({}+[])['+compile_int(8)+']',
  // bject
  ']': '({}+[])['+compile_int(14)+']',
  'f': '(![]+[])['+compile_int(0)+']',
  // a
  'l': '(![]+[])['+compile_int(2)+']',
  's': '(![]+[])['+compile_int(3)+']',
  // e
  't': '(!![]+[])['+compile_int(0)+']',
  'r': '(!![]+[])['+compile_int(1)+']',
  'u': '(!![]+[])['+compile_int(2)+']',
  'e': '(!![]+[])['+compile_int(3)+']',
  '\/': '(/\\\\/+[])['+compile_int(0)+']',
  '\\': '(/\\\\/+[])['+compile_int(1)+']',
  'I': '((+!![]/+[])+[])['+compile_int(0)+']',
  'n': '((+!![]/+[])+[])['+compile_int(1)+']',
  // f
  'i': '((+!![]/+[])+[])['+compile_int(3)+']',
  // nit
  'y': '((+!![]/+[])+[])['+compile_int(7)+']',
  //un
  'd': '([]['+compile_int(0)+']+[])['+compile_int(2)+']',
  // efined
};
// wanted: m C h in relatively short fashion

function compile_string(s, as_code = false) {
  const compiled = [];

  for (const c of s) {
    const req = '$('+compile_int(c.charCodeAt(0))+')';
    if (c in char_lits && (char_lits[c].length <= req.length || !as_code))
      compiled.push(char_lits[c]);
    else
      compiled.push(req);
  }

  return compiled.join('+');
}


// these are ~300 chars, will require compression
char_lits['p'] = '(/</['+compile_string('constructor')+']+[])['+compile_int(14)+']';
char_lits['S'] = '([]+([]+[])['+compile_string('constructor')+'])['+compile_int(9)+']';
char_lits['g'] = '([]+([]+[])['+compile_string('constructor')+'])['+compile_int(14)+']';
char_lits['('] = '([]+([]+[])['+compile_string('constructor')+'])['+compile_int(15)+']';
char_lits[')'] = '([]+([]+[])['+compile_string('constructor')+'])['+compile_int(16)+']';
char_lits['{'] = '([]+([]+[])['+compile_string('constructor')+'])['+compile_int(18)+']';
char_lits['}'] = '([]+([]+[])['+compile_string('constructor')+'])['+compile_int(34)+']';
char_lits['v'] = '([]+([]+[])['+compile_string('constructor')+'])['+compile_int(25)+']';
char_lits['m'] = '((+[])['+compile_string('constructor')+']+[])['+compile_int(11)+']';

// these are ~800 chars, will require great compression
char_lits['h'] = '('+compile_int(17)+')['+compile_string('toString')+']('+compile_int(24)+')';
char_lits['C'] = '((()=>{})['+compile_string('constructor')+']('+compile_string('return escape')+')()('+compile_string('\\')+'))['+compile_int(2)+']';

const prelude = '$=([]+[])['+compile_string('constructor')+']['+compile_string('fromCharCode')+'];';

function compile_code(code) {
  return prelude + '(()=>{})['+compile_string('constructor')+']('+compile_string(code, true)+')()';
}

if (typeof process === 'undefined')
  process = global.process;

if (process.argv.length < 3) {
  console.log('Usage:', process.argv[0], process.argv[1], '<input file>');
  process.exit(1);
}

if (process.argv[2] === '-') {
  const data = [];
  process.stdin.on('data', function (fragment) {
    data.push(fragment);
  });
  process.stdin.on('close', function() {
    const code = Buffer.concat(data).toString();
    console.log(compile_code(code));
  });
} else {
  if (typeof require === 'undefined')
    require = global.require || global.process.mainModule.constructor._load;
  const fs = require('fs');

  const code = fs.readFileSync(process.argv[2], {encoding: 'utf8'});
  console.log(compile_code(code));
}