HTTPS 加载器
在当前的 Node.js 中,不支持以 https://
开头的说明符。
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 'https';
export function resolve(specifier, context, defaultResolve) {
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 {
url: specifier
};
} else if (parentURL && parentURL.startsWith('https://')) {
return {
url: new URL(specifier, parentURL).href
};
}
// 让 Node.js 处理所有其他说明符。
return defaultResolve(specifier, context, defaultResolve);
}
export function getFormat(url, context, defaultGetFormat) {
// 此加载器假定所有网络提供的 JavaScript 都是 ES 模块代码。
if (url.startsWith('https://')) {
return {
format: 'module'
};
}
// 让 Node.js 处理所有其他 URL。
return defaultGetFormat(url, context, defaultGetFormat);
}
export function getSource(url, context, defaultGetSource) {
// 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({ source: data }));
}).on('error', (err) => reject(err));
});
}
// 让 Node.js 处理所有其他 URL。
return defaultGetSource(url, context, defaultGetSource);
}
// 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 unsupported. 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 'https';
export function resolve(specifier, context, defaultResolve) {
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 {
url: specifier
};
} else if (parentURL && parentURL.startsWith('https://')) {
return {
url: new URL(specifier, parentURL).href
};
}
// Let Node.js handle all other specifiers.
return defaultResolve(specifier, context, defaultResolve);
}
export function getFormat(url, context, defaultGetFormat) {
// This loader assumes all network-provided JavaScript is ES module code.
if (url.startsWith('https://')) {
return {
format: 'module'
};
}
// Let Node.js handle all other URLs.
return defaultGetFormat(url, context, defaultGetFormat);
}
export function getSource(url, context, defaultGetSource) {
// 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({ source: data }));
}).on('error', (err) => reject(err));
});
}
// Let Node.js handle all other URLs.
return defaultGetSource(url, context, defaultGetSource);
}
// 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
.