Double space

script

// double space

(() => {

  const getLines = () => {
    const e = editor;
    const t =
      e.getSelectedRange()[1] > 0 ?
      e.getTextInRange(...e.getSelectedLineRange()) :
      e.getText();
    return t.split('\n');
  };

  const setLines = (l) => {
    const t = l.join('\n') + '\n';
    const e = editor;
    if (e.getSelectedRange()[1] > 0) {
      const sel = e.getSelectedLineRange();
      e.setTextInRange(...sel, t);
      e.setSelectedRange(sel[0], t.length);
    } else {
      e.setText(t);
    }
  };

  const double = (l) => {
    return l.filter(l => l.trim())
      .reduce((xs, l) => { xs.push(l, ''); return xs; }, []);
  };

  setLines(double(getLines()));

})();