Node 控制台进度条

index.js

const ProgressBar = require('./progress-bar');

const pb = new ProgressBar('下载进度', 50);
let num = 0,
  total = 200;

function download() {
  if (num <= total) {
    pb.render({ completed: num, total });
    ++num;
    setTimeout(download, 100);
  }
}

download();

progress-bar.js

const slog = require('single-line-log').stdout;

class ProgressBar {
  constructor(describtion = 'Progress', length = 25) {
    this.describtion = describtion;
    this.length = length;
  }
  render(opts) {
    const percent = (opts.completed / opts.total).toFixed(4);
    const cellNum = Math.floor(percent * this.length);
    let cell = '';
    for (let i = 0; i < cellNum; ++i) cell += '█';

    let empty = '';
    for (let i = 0; i < this.length - cellNum; ++i) empty += '░';

    const cmdText = `${this.describtion}: ${(100 * percent).toFixed(
      2
    )}% ${cell}${empty}`;
    slog(cmdText);
  }
}

module.exports = ProgressBar;