setinha.js

import { stdin as input, stdout as output } from 'process';
import { emitKeypressEvents } from 'readline';

function clearConsole(lengthOfOptions) {
  //adapted from sindresorhus ansi-escape module
  const ESC = '\u001B['
  const eraseLine = ESC + '2K';
  const cursorUp = (count = 1) => ESC + count + 'A'
  const cursorLeft = ESC + 'G'

  let clear = '';

  for (let i = 0; i < lengthOfOptions; i++)
    clear += eraseLine + (i < lengthOfOptions - 1 ? cursorUp() : '');

  if (lengthOfOptions) clear += cursorLeft;
  
  return clear;
}

function ask(question, { lengthOfOptions, onUp, onDown, onSelect, renderOption }) {
  console.log(question);
  const renderOptions = renderOptionsBuilder(renderOption, lengthOfOptions);
  emitKeypressEvents(input);
  input.setRawMode(true);
  input.resume();
  input.on('keypress', (_, key) => {
    if (key) {
      if (key.name === 'down') {
        onDown()
        renderOptions()
      }
      else if (key.name === 'up') {
        onUp();
        renderOptions()
      }
      else if (key.name === 'escape' || (key.name === 'c' && key.ctrl)) {
        close()
      } else if (key.name === 'return') {
        output.write(clearConsole(lengthOfOptions+1));
        onSelect()
        close()
      }
    }
  });

  renderOptions(true);
}

function close() {
  input.setRawMode(false)
  input.pause()
  process.exit(0)
}

function renderOptionsBuilder(renderOption, lengthOfOptions) {
  return (isFirstRender = false) => {
    if (!isFirstRender) output.write(clearConsole(lengthOfOptions));

    for (let i=0; i < lengthOfOptions; i++) output.write(renderOption(i))
  }
}

const main = () => {
  const question = 'O que você prefere comer?';

  const options = ['bosta', 'cocô', 'kiwi', 'insetos no geral', 'sei la'];
  let selectedOption = 0;
  ask(question, {
    lengthOfOptions: options.length,
    onUp: () => {
      if (selectedOption <= 0) return;
      selectedOption -= 1;
    },
    onDown: () => {
      if (selectedOption >= options.length - 1) return;
      selectedOption += 1;
    },
    onSelect: () => {
      console.log(`${question} ${options[selectedOption]}`);
    },
    renderOption: (index) => {

      const isSelected = index === selectedOption;
      const isEnding = index === options.length - 1;
      const optionText = `${isSelected ? `> ${options[index]}` : `  ${options[index]}`}${isEnding ? '' : '\n'}`;
      return optionText;
    }
  })
}

main()