顶层 await

\Top-level await

await 关键字可以用在 ECMAScript 模块的顶层主体中。

\The await keyword may be used in the top level body of an ECMAScript module.

假设 a.mjs 具有

\Assuming an a.mjs with

export const five = await Promise.resolve(5); 拷贝

并且 b.mjs 具有

\And a b.mjs with

import { five } from './a.mjs';
console.log(five); // Logs `5` 拷贝

node b.mjs # works 拷贝

如果顶层 await 表达式永远无法解析,则 node 进程将退出并返回 13 状态码。

\If a top level await expression never resolves, the node process will exit with a 13 status code.

import { spawn } from 'node:child_process';
import { execPath } from 'node:process';
spawn(execPath, [
 '--input-type=module',
 '--eval',
 // Never-resolving Promise:
 'await new Promise(() => {})',
]).once('exit', (code) => {
 console.log(code); // Logs `13`
}); 拷贝