задача кодевам

index.js

необходимо чтобы на сходе давать команду и на выходе после расчета нужно показать позицию и ориентацию. 
суть в том что есть газонокосилка ездящая налево\направо\прямо и передвигаться она может ездить туда-сюда без гранично
и вот 

const _d = {
  r: 'r',
  l: 'l'
};

class Mower {

  directions = [
    {name: 'E', axis: 'x', direction: 1},
    {name: 'S', axis: 'y', direction: 1},
    {name: 'W', axis: 'x', direction: -1},
    {name: 'N', axis: 'y', direction: -1}
  ];

  commands = {
    [_d.r]: {name: 'R', step: 1, botton: 0, top: 3, direction: 'clockwise'},
    [_d.l]: {name: 'L', step: -1, top: 0, bottom: 3, direction: 'counter-clockwise'},
    a: {name: 'A', direction: 'advance'}
  }

  position = {
    x: 0,
    y: 0,
    orientation: this.directions[0].name
  }

  _get_orientation_index = () =>
    this.directions.findIndex( e => e === this.position.orientation );

  _turn_around = (direction) => {
    let dir_index;
    this._get_orientation_index === this.commands[direction].top
      ? dir_index = this.commands[direction].bottom + this.commands[direction].step
      : dir_index = this.directions[this._get_orientation_index + this.commands[direction].step];
    this.position.orientation = this.directions[dir_index].name;
  }

  _advance = () => {
    const orientation = this.position.orientation;
    const i = this.directions.findIndex(e => e.name === orientation);
    this.position[i.axis] = this.position[i.axis] + this.position[i.direction];
  }

  _perform_move = (move) => { 
    switch (true) {
      case move === this.commands.r.name: {
        this._turn_around(_d.r);
        break;
      }
      case move === this.commands.l.name: {
        this._turn_around(_d.l);
        break;
      }
      case move === this.commands.a.name: {
        this._advance();
        break;
      }
    }
  }

  run = (passed_commands) => {
    Array.from(passed_commands).map(e => this._perform_move(e));
    this.inform_user();
  }

  inform_user = () => `The mower is at ${this.position.x}, ${this.position.y} and oriented on ${this.position.orientation}`
}

const mower = new Mower();
mower.run('');
mower.run('A');
mower.run('L');
mower.run('AAAR');