unpkg/modules/middleware/fetchPackage.js

123 lines
3.2 KiB
JavaScript

import createPackageURL from '../utils/createPackageURL.js';
import createSearch from '../utils/createSearch.js';
import { getPackageConfig, resolveVersion } from '../utils/npm.js';
function semverRedirect(req, res, newVersion) {
res
.set({
'Cache-Control': 'public, s-maxage=600, max-age=60', // 10 mins on CDN, 1 min on clients
'Cache-Tag': 'redirect, semver-redirect'
})
.redirect(
302,
createPackageURL(req.packageName, newVersion, req.filename, req.search)
);
}
const leadingSlashes = /^\/*/;
function filenameRedirect(req, res) {
let filename;
if (req.query.module != null) {
// See https://github.com/rollup/rollup/wiki/pkg.module
filename = req.packageConfig.module || req.packageConfig['jsnext:main'];
if (!filename) {
// https://nodejs.org/api/esm.html#esm_code_package_json_code_code_type_code_field
if (req.packageConfig.type === 'module') {
// Use whatever is in pkg.main or index.js
filename = req.packageConfig.main || '/index.js';
} else if (
req.packageConfig.main &&
/\.mjs$/.test(req.packageConfig.main)
) {
// Use .mjs file in pkg.main
filename = req.packageConfig.main;
}
}
if (!filename) {
return res
.status(404)
.type('text')
.send(`Package ${req.packageSpec} does not contain an ES module`);
}
} else if (
req.query.main &&
req.packageConfig[req.query.main] &&
typeof req.packageConfig[req.query.main] === 'string'
) {
// Deprecated, see #63
filename = req.packageConfig[req.query.main];
} else if (
req.packageConfig.unpkg &&
typeof req.packageConfig.unpkg === 'string'
) {
filename = req.packageConfig.unpkg;
} else if (
req.packageConfig.browser &&
typeof req.packageConfig.browser === 'string'
) {
// Deprecated, see #63
filename = req.packageConfig.browser;
} else {
filename = req.packageConfig.main || '/index.js';
}
// Redirect to the exact filename so relative imports
// and URLs resolve correctly.
res
.set({
'Cache-Control': 'public, max-age=31536000', // 1 year
'Cache-Tag': 'redirect, filename-redirect'
})
.redirect(
302,
createPackageURL(
req.packageName,
req.packageVersion,
filename.replace(leadingSlashes, '/'),
createSearch(req.query)
)
);
}
/**
* Fetch the package config. Redirect to the exact version if the request
* targets a tag or uses semver, or to the exact filename if the request
* omits the filename.
*/
export default async function fetchPackage(req, res, next) {
const version = await resolveVersion(req.packageName, req.packageVersion);
if (!version) {
return res
.status(404)
.type('text')
.send(`Cannot find package ${req.packageSpec}`);
}
if (version !== req.packageVersion) {
return semverRedirect(req, res, version);
}
req.packageConfig = await getPackageConfig(
req.packageName,
req.packageVersion
);
if (!req.packageConfig) {
// TODO: Log why.
return res
.status(500)
.type('text')
.send(`Cannot get config for package ${req.packageSpec}`);
}
if (!req.filename) {
return filenameRedirect(req, res);
}
next();
}