如何中止 readline 接口问题？

Question

TL;DR
Once you call rl.question(query[, options], callback) it looks like there is no way to cancel the question as long als it's pending an answer.
Is there a way to cleanly abort a readline interface question?

我运行使用原生Node.jsReadline模块遇到问题：

我想提供一个简单的暂停或中止功能来干预子程序（如果它花费的时间太长或需要在检查时暂停）。我通过在 stdio 上询问一个可以与运行子例程并行回答的问题来实现这一点。如果给出答案，就会开始干预。

一切正常。但是，如果子例程完成并且当时没有给出答案，则不再需要该问题，因此我正在寻找一种干净的方法来“中止”所提出的问题。

一旦您致电 rl.question(query[, options], callback)，似乎就无法取消问题，因为它正在等待回答。

我创建了这个测试代码来重现问题：

// setting up the CLI
const rl = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});

// ...somewhere later:

// mockup of subroutine starting 
console.log('Start task...');

// ask question to intervene
rl.question('(p)ause/(a)bort: ', answer => {
  console.log(`You entered ${answer}`);
  // ...handle intervene. 
});

// mockup of subroutine ending
setTimeout(()=>{
  console.log('... task has ended. Question can be canelled.');
  // ...cancel the question
}, 5000);

我想出的临时解决办法是关闭界面，清线再打开新界面：

let rl = // ...
//...

// mockup of subroutine ending
setTimeout(() => {
  // ... cancel the question
  rl.close();
  process.stdout.clearLine();
  process.stdout.cursorTo(0);
  rl = require('readline').createInterface({
    input: process.stdin,
    output: process.stdout
  });
  console.log('... task has ended (and question was closed in a very dirty way).');
}, 5000);

它有效...但此解决方案违反了多个编码约定（关注点分离、模块化...）。
原来的readline接口是在程序的一个非常不同的位置初始化的，就这样随便关闭再打开我感觉很不爽。（想象一下代码的另一部分仍然保留旧实例，.createInterface() 的原始选项得到更新，等等）

有没有办法彻底中止 readline 接口问题？

Answer 1

听起来你需要一个中止控制器

// setting up the CLI
const rl = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});

// mockup of subroutine starting 
console.log('Start task...');

// ask question to intervene
const aborter = new AbortController();
rl.question('(p)ause/(a)bort: ', { signal: aborter.signal }, answer => {
  console.log(`You entered ${answer}`);
  // ...handle intervene. 
});

// mockup of subroutine ending
setTimeout(() => {
  console.log('... task has ended. Question can be caneled.');
  aborter.abort();
}, 5000);

如果你的node版本不支持abort controller，可以直接写入接口

// setting up the CLI
const rl = require('readline').createInterface({
  input: process.stdin,
  output: process.stdout
});

// mockup of subroutine starting 
console.log('Start task...');

// ask question to intervene
rl.question('(p)ause/(a)bort: ', answer => {
  console.log(`You entered ${answer}`);
  // ...handle 'e' answer as ended here here
  // ...handle intervene. 
});

// mockup of subroutine ending
setTimeout(() => {
  console.log('... task has ended. Question can be caneled.');
  rl.write("e\n");
}, 5000);

如何中止 readline 接口问题？

How to abort a readline interface question?

javascript

stdio

node.js