NodeJS V18稳定版本正式发布，这个特性太棒了

前几天，Node.js v18作为当前的稳定版本发布了。我们归纳了 v18 的一些更新。

全局 fetch

Node.js在——试验性-fetch后有了一个全局fetch，它允许你在Node.js中原生使用浏览器fetchAPI。在v18中，实验性的Fetch API默认是可用的。

fetch('https://example.com/todos/1')
  .then(response => response.json())
  .then(json => console.log(json))

你还可以访问FormData、header、Request和Response对象。

访问Web流媒体API

Node.js现在对Web流媒体API提供了实验性支持:

fetch('https://example.com/api/articles?per_page=1000&page=1')
    .then(response => response.body)
    .then(rb => rb.getReader())
    .then(reader => {
        const stream = new ReadableStream({
            ...
        })
    })

内置测试框架

node .js现在有一个内置的测试框架，可以在import('node:test')访问：

import test from 'node:test';
import assert from 'node:assert';

test('true is not false', async t => {
    assert.strictEqual(true, !false);
});

测试：

$ node test.js
(node:83584) ExperimentalWarning: The test runner is an experimental feature. This feature could change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
TAP version 13
ok 1 - true is not false
  ---
  duration_ms: 0.000730654
  ...
1..1
# tests 1
# pass 1
# fail 0
# skipped 0
# todo 0
# duration_ms 0.074570679

输出为TAP格式。你可以使用tap或faucet CLIs来打印它:

$ npm i -g tap
$ tap test.js
index.js 2> (node:84725) ExperimentalWarning: The test runner is an experimental feature. This feature could change at any time
index.js 2> (Use `node --trace-warnings ...` to show where the warning was created)
 PASS  index.js 1 OK 239.361ms



  🌈 SUMMARY RESULTS 🌈


Suites:   1 passed, 1 of 1 completed
Asserts:  1 passed, of 1
Time:   415.463ms
----------|---------|----------|---------|---------|-------------------
File      | % Stmts | % Branch | % Funcs | % Lines | Uncovered Line #s
----------|---------|----------|---------|---------|-------------------
All files |       0 |        0 |       0 |       0 |
----------|---------|----------|---------|---------|-------------------

• faucet:

$ npm i -g faucet
$ node test.js | faucet

(node:84914) ExperimentalWarning: The test runner is an experimental feature. This feature could change at any time
(Use `node --trace-warnings ...` to show where the warning was created)
✓ true is not false
# tests 1
# pass 1
✓ skipped 0
✓ todo 0
✓ duration_ms 0.076367098

二进制文件

用户现在可以使用自定义V8启动快照来构建Node.js，以提高性能。

通俗地说，这意味着你可以在node.js源代码中缓存一些依赖项，以提高启动时间。

$ cd /where/is/node/source/code
$ ./configure --node-snapshot-main=marked.js # where marked.js is the source of the marked library
$ make node

---

// your-program.js
// globalThis.marked is now deserialized from the snapshot
// so node.js doesnt need to parse it again
// which improves startup time
const marked = globalThis.marked;
marked(/* ... */);

---

$ out/Release/node your-program.js

Node.js正在为此开发JS api，这意味着我们基本上可以将Node.js应用构建为可分发的二进制文件!

Node.js v18有一些真正令人兴奋的新特性。我一直在等待fetch API，我一直希望Node.js有二进制文件。测试框架也很简洁!