回调和基于 promise 的操作的顺序

¥Ordering of callback and promise-based operations

因为它们是由底层线程池异步地执行，所以当使用回调或基于 promise 的方法时无法保证顺序。

¥Because they are executed asynchronously by the underlying thread pool, there is no guaranteed ordering when using either the callback or promise-based methods.

例如，以下内容容易出错，因为 fs.stat() 操作可能会在 fs.rename() 操作之前完成：

¥For example, the following is prone to error because the fs.stat() operation might complete before the fs.rename() operation:

const fs = require('node:fs');

fs.rename('/tmp/hello', '/tmp/world', (err) => {
  if (err) throw err;
  console.log('renamed complete');
});
fs.stat('/tmp/world', (err, stats) => {
  if (err) throw err;
  console.log(`stats: ${JSON.stringify(stats)}`);
}); 拷贝

通过在调用另一个之前等待前一个的结果来正确地排序操作，这是很重要的：

¥It is important to correctly order the operations by awaiting the results of one before invoking the other:

import { rename, stat } from 'node:fs/promises';

const oldPath = '/tmp/hello';
const newPath = '/tmp/world';

try {
  await rename(oldPath, newPath);
  const stats = await stat(newPath);
  console.log(`stats: ${JSON.stringify(stats)}`);
} catch (error) {
  console.error('there was an error:', error.message);
}const { rename, stat } = require('node:fs/promises');

(async function(oldPath, newPath) {
  try {
    await rename(oldPath, newPath);
    const stats = await stat(newPath);
    console.log(`stats: ${JSON.stringify(stats)}`);
  } catch (error) {
    console.error('there was an error:', error.message);
  }
})('/tmp/hello', '/tmp/world');拷贝

或者，当使用回调 API 时，将 fs.stat() 调用移动到 fs.rename() 操作的回调中。

¥Or, when using the callback APIs, move the fs.stat() call into the callback of the fs.rename() operation:

import { rename, stat } from 'node:fs';

rename('/tmp/hello', '/tmp/world', (err) => {
  if (err) throw err;
  stat('/tmp/world', (err, stats) => {
    if (err) throw err;
    console.log(`stats: ${JSON.stringify(stats)}`);
  });
});const { rename, stat } = require('node:fs/promises');

rename('/tmp/hello', '/tmp/world', (err) => {
  if (err) throw err;
  stat('/tmp/world', (err, stats) => {
    if (err) throw err;
    console.log(`stats: ${JSON.stringify(stats)}`);
  });
});拷贝