HTTPS 加载器
在当前的 Node.js 中,以 https://
开头的说明符是实验性的(参见 HTTPS 和 HTTP 导入)。
下面的加载器注册钩子以启用对此类说明符的基本支持。 虽然这似乎是对 Node.js 核心功能的重大改进,但实际使用这个加载器有很大的缺点:性能比从磁盘加载文件慢得多,没有缓存,也没有安全性。
// https-loader.mjs
import { get } from 'node:https';
export function resolve(specifier, context, nextResolve) {
const { parentURL = null } = context;
// 通常,Node.js 会在以 'https://' 开头的说明符上出错,
// 因此此钩子会拦截它们并将它们转换为绝对 URL,
// 以便传给下面的后面的钩子。
if (specifier.startsWith('https://')) {
return {
shortCircuit: true,
url: specifier,
};
} else if (parentURL && parentURL.startsWith('https://')) {
return {
shortCircuit: true,
url: new URL(specifier, parentURL).href,
};
}
// 让 Node.js 处理所有其他说明符。
return nextResolve(specifier);
}
export function load(url, context, nextLoad) {
// 要通过网络加载 JavaScript,
// 则需要获取并返回它。
if (url.startsWith('https://')) {
return new Promise((resolve, reject) => {
get(url, (res) => {
let data = '';
res.on('data', (chunk) => data += chunk);
res.on('end', () => resolve({
// 本示例假设所有网络提供的 JavaScript
// 都是 ES 模块代码。
format: 'module',
shortCircuit: true,
source: data,
}));
}).on('error', (err) => reject(err));
});
}
// 让 Node.js 处理所有其他 URL。
return nextLoad(url);
}
// main.mjs
import { VERSION } from 'https://coffeescript.org/browser-compiler-modern/coffeescript.js';
console.log(VERSION);
使用前面的加载器,运行 node --experimental-loader ./https-loader.mjs ./main.mjs
会在 main.mjs
中的 URL 处按照模块打印当前版本的 CoffeeScript。
In current Node.js, specifiers starting with https://
are experimental (see
HTTPS and HTTP imports).
The loader below registers hooks to enable rudimentary support for such specifiers. While this may seem like a significant improvement to Node.js core functionality, there are substantial downsides to actually using this loader: performance is much slower than loading files from disk, there is no caching, and there is no security.
// https-loader.mjs
import { get } from 'node:https';
export function resolve(specifier, context, nextResolve) {
const { parentURL = null } = context;
// Normally Node.js would error on specifiers starting with 'https://', so
// this hook intercepts them and converts them into absolute URLs to be
// passed along to the later hooks below.
if (specifier.startsWith('https://')) {
return {
shortCircuit: true,
url: specifier,
};
} else if (parentURL && parentURL.startsWith('https://')) {
return {
shortCircuit: true,
url: new URL(specifier, parentURL).href,
};
}
// Let Node.js handle all other specifiers.
return nextResolve(specifier);
}
export function load(url, context, nextLoad) {
// For JavaScript to be loaded over the network, we need to fetch and
// return it.
if (url.startsWith('https://')) {
return new Promise((resolve, reject) => {
get(url, (res) => {
let data = '';
res.on('data', (chunk) => data += chunk);
res.on('end', () => resolve({
// This example assumes all network-provided JavaScript is ES module
// code.
format: 'module',
shortCircuit: true,
source: data,
}));
}).on('error', (err) => reject(err));
});
}
// Let Node.js handle all other URLs.
return nextLoad(url);
}
// main.mjs
import { VERSION } from 'https://coffeescript.org/browser-compiler-modern/coffeescript.js';
console.log(VERSION);
With the preceding loader, running
node --experimental-loader ./https-loader.mjs ./main.mjs
prints the current version of CoffeeScript per the module at the URL in
main.mjs
.