核弹发射代码

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

class ProgressBar {
  constructor(description, barLength) {
    this.description = description || 'Progress';
    this.barLength = barLength || 25;
  }
  render (options) {
    const percent = (options.completed / options.total).toFixed(4);
    const cell_num = Math.floor(percent * this.barLength);

    let cell = '';
    for (let i = 0; i < cell_num; i++) {
      cell += '█';
    }

    let empty = '';
    for (let j = 0; j < this.barLength - cell_num; j++) {
      empty += '░';
    }

    const cmdText = this.description + ': ' + (100 * percent).toFixed(2) + '% ' + cell + empty;

    slog(cmdText);
  }
}

const awaitTime = async (time) => {
  return new Promise((resolve) => {
    setTimeout(() => {
      resolve();
    }, time)
  });
};

const start = async () => {
  let progressBar = null;
  let num = 0;
  let total = 100;
  const handle = async (data, beforeMessage) => {
    if (num <= total) {
      data.render({ completed: num, total: total });
      num++;

      return new Promise((resolve) => {
        setTimeout(async () => {
          await handle(data, beforeMessage)
          resolve();
        }, 30)
      });
    }
    await awaitTime(300);
    slog(beforeMessage);
  }

  progressBar = new ProgressBar('检查发射环境', 50);
  await handle(progressBar, '发射环境检查完毕... 开始启动发射程序...');

  await awaitTime(1000);

  total = 100;
  num = 0;
  progressBar = new ProgressBar('启动发射程序', 50);
  await handle(progressBar, '启动发射程序完毕... 核弹即将发射...');
  setTimeout(() => { return }, 1000)
  launch();
}
start();

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