diff --git a/server/middleware/PackageUtils.js b/server/middleware/PackageUtils.js index 7ed5810..2925e3f 100644 --- a/server/middleware/PackageUtils.js +++ b/server/middleware/PackageUtils.js @@ -25,16 +25,16 @@ const parsePackageURL = (url) => { return null const packageName = match[1] - const version = decodeParam(match[2]) || 'latest' + const packageVersion = decodeParam(match[2]) || 'latest' const filename = decodeParam(match[3]) - return { // If the URL is /@scope/name@version/path.js?main=browser: - pathname, // /@scope/name@version/path.js - search, // ?main=browser - query, // { main: 'browser' } - packageName, // @scope/name - version, // version - filename // /path.js + return { // If the URL is /@scope/name@version/file.js?main=browser: + pathname, // /@scope/name@version/path.js + search, // ?main=browser + query, // { main: 'browser' } + packageName, // @scope/name + packageVersion, // version + filename // /file.js } } diff --git a/server/middleware/checkBlacklist.js b/server/middleware/checkBlacklist.js new file mode 100644 index 0000000..61eba20 --- /dev/null +++ b/server/middleware/checkBlacklist.js @@ -0,0 +1,14 @@ +/** + * Check the blacklist to see if we can serve files from this package. + */ +function checkBlacklist(blacklist) { + return function (req, res, next) { + if (blacklist.includes(req.packageName)) { + res.status(403).send(`Package ${req.packageName} is blacklisted`) + } else { + next() + } + } +} + +module.exports = checkBlacklist diff --git a/server/middleware/fetchPackage.js b/server/middleware/fetchPackage.js new file mode 100644 index 0000000..563b73f --- /dev/null +++ b/server/middleware/fetchPackage.js @@ -0,0 +1,70 @@ +const fs = require('fs') +const path = require('path') +const tmpdir = require('os-tmpdir') +const { maxSatisfying: maxSatisfyingVersion } = require('semver') +const { createPackageURL } = require('./PackageUtils') +const { getPackageInfo, getPackage } = require('./RegistryUtils') + +function checkLocalCache(dir, callback) { + fs.stat(path.join(dir, 'package.json'), function (error, stats) { + callback(stats && stats.isFile()) + }) +} + +function createTempPath(name) { + return path.join(tmpdir(), `unpkg-${name}`) +} + +/** + * Fetch the package from the registry and store a local copy on disk. + * Redirect if the URL does not specify an exact req.packageVersion number. + */ +function fetchPackage(registryURL) { + return function (req, res, next) { + req.packageDir = createTempPath(req.packageSpec) + + // TODO: fix race condition! (see #38) + // TODO: ensure req.packageInfo is always populated so we can re-use later + checkLocalCache(req.packageDir, function (isCached) { + if (isCached) + return next() // Best case: we already have this package on disk. + + // Fetch package info from NPM. + getPackageInfo(registryURL, req.packageName, function (error, packageInfo) { + if (error) + return res.status(500).send(error.message || error) + + if (packageInfo == null || packageInfo.versions == null) + return res.status(404).send(`Cannot find package "${req.packageName}"`) + + const { versions, 'dist-tags': tags } = packageInfo + + if (req.packageVersion in versions) { + // A valid request for a package we haven't downloaded yet. + const packageConfig = versions[req.packageVersion] + const tarballURL = packageConfig.dist.tarball + + getPackage(tarballURL, req.packageDir, function (error) { + if (error) { + res.status(500).send(error.message || error) + } else { + next() + } + }) + } else if (req.packageVersion in tags) { + res.redirect(createPackageURL(req.packageName, tags[req.packageVersion], req.filename, req.search)) + } else { + const maxVersion = maxSatisfyingVersion(Object.keys(versions), req.packageVersion) + + if (maxVersion) { + res.redirect(createPackageURL(req.packageName, maxVersion, req.filename, req.search)) + } else { + res.status(404).send(`Cannot find package ${req.packageSpec}`) + } + } + }) + }) + } +} + +module.exports = fetchPackage diff --git a/server/middleware/findFile.js b/server/middleware/findFile.js new file mode 100644 index 0000000..7e7e169 --- /dev/null +++ b/server/middleware/findFile.js @@ -0,0 +1,120 @@ +const fs = require('fs') +const path = require('path') + +const ResolveExtensions = [ '', '.js', '.json' ] + +/** + * Resolves a path like "lib/file" into "lib/file.js" or "lib/file.json" + * depending on which one is available, similar to require('lib/file'). + */ +function resolveFile(base, useIndex, callback) { + ResolveExtensions.reduceRight(function (next, ext) { + const file = base + ext + + return function () { + fs.stat(file, function (error, stats) { + if (error) { + if (error.code === 'ENOENT' || error.code === 'ENOTDIR') { + next() + } else { + callback(error) + } + } else if (useIndex && stats.isDirectory()) { + resolveFile(path.join(file, 'index'), false, function (error, indexFile, indexStats) { + if (error) { + callback(error) + } else if (indexFile) { + callback(null, indexFile, indexStats) + } else { + next() + } + }) + } else { + callback(null, file, stats) + } + }) + } + }, callback)() +} + +/** + * Determine which file we're going to serve and get its stats. + * Redirect if the request targets a directory with no trailing slash. + */ +function findFile() { + return function (req, res, next) { + if (req.filename) { + const base = path.join(req.packageDir, req.filename) + + // Based on the URL, figure out which file they want. + resolveFile(base, false, function (error, file, stats) { + if (error) + console.error(error) + + if (file == null) { + res.status(404).send(`Cannot find file "${req.filename}" in package ${req.packageSpec}`) + } else if (stats.isDirectory() && req.pathname[req.pathname.length - 1] !== '/') { + // Append / to directory URLs. + res.redirect(`${req.pathname}/${req.search}`) + } else { + req.file = file.replace(req.packageDir, '') + req.stats = stats + next() + } + }) + } else { + // No filename in the URL. Try to figure out which file they want by + // checking package.json's "unpkg", "browser", and "main" fields. + fs.readFile(path.join(req.packageDir, 'package.json'), 'utf8', function (error, data) { + if (error) { + console.error(error) + return res.status(500).send(`Cannot read ${req.packageSpec}/package.json`) + } + + let packageConfig + try { + packageConfig = JSON.parse(data) + } catch (error) { + return res.status(500).send(`Cannot parse ${req.packageSpec}/package.json: ${error.message}`) + } + + let mainFilename + const queryMain = query && query.main + + if (queryMain) { + if (!(queryMain in packageConfig)) + return res.status(404).send(`Cannot find field "${queryMain}" in ${req.packageSpec}/package.json`) + + mainFilename = packageConfig[queryMain] + } else { + if (typeof packageConfig.unpkg === 'string') { + // The "unpkg" field allows packages to explicitly declare the + // file to serve at the bare URL (see #59). + mainFilename = packageConfig.unpkg + } else if (typeof packageConfig.browser === 'string') { + // Fall back to the "browser" field if declared (only support strings). + mainFilename = packageConfig.browser + } else { + // If there is no main, use "index" (same as npm). + mainFilename = packageConfig.main || 'index' + } + } + + resolveFile(path.join(req.packageDir, mainFilename), true, function (error, file, stats) { + if (error) + console.error(error) + + if (file == null) { + res.status(404).send(`Cannot find main file "${mainFilename}" in package ${req.packageSpec}`) + } else { + req.file = file.replace(req.packageDir, '') + req.stats = stats + next() + } + }) + }) + } + } +} + +module.exports = findFile diff --git a/server/middleware/index.js b/server/middleware/index.js index 83f4c62..81a1a84 100644 --- a/server/middleware/index.js +++ b/server/middleware/index.js @@ -1,71 +1,9 @@ -const tmpdir = require('os-tmpdir') -const { join: joinPaths } = require('path') -const { stat: statFile, readFile } = require('fs') -const { maxSatisfying: maxSatisfyingVersion } = require('semver') -const { parsePackageURL, createPackageURL } = require('./PackageUtils') -const { getPackageInfo, getPackage } = require('./RegistryUtils') -const { generateDirectoryIndexHTML } = require('./IndexUtils') -const { generateMetadata } = require('./MetadataUtils') -const { getFileType } = require('./FileUtils') -const { - sendNotFoundError, - sendInvalidURLError, - sendServerError, - sendRedirect, - sendFile, - sendText, - sendJSON, - sendHTML -} = require('./ResponseUtils') - -const oneMinute = 60 -const oneDay = oneMinute * 60 * 24 -const oneYear = oneDay * 365 - -const checkLocalCache = (dir, callback) => - statFile(joinPaths(dir, 'package.json'), (error, stats) => { - callback(stats && stats.isFile()) - }) - -const createTempPath = (name) => - joinPaths(tmpdir(), `unpkg-${name}`) - -const ResolveExtensions = [ '', '.js', '.json' ] - -/** - * Resolves a path like "lib/file" into "lib/file.js" or - * "lib/file.json" depending on which one is available, similar - * to how require('lib/file') does. - */ -const resolveFile = (path, useIndex, callback) => { - ResolveExtensions.reduceRight((next, ext) => { - const file = path + ext - - return () => { - statFile(file, (error, stats) => { - if (error) { - if (error.code === 'ENOENT' || error.code === 'ENOTDIR') { - next() - } else { - callback(error) - } - } else if (useIndex && stats.isDirectory()) { - resolveFile(joinPaths(file, 'index'), false, (error, indexFile, indexStats) => { - if (error) { - callback(error) - } else if (indexFile) { - callback(null, indexFile, indexStats) - } else { - next() - } - }) - } else { - callback(null, file, stats) - } - }) - } - }, callback)() -} +const express = require('express') +const parseURL = require('./parseURL') +const checkBlacklist = require('./checkBlacklist') +const fetchPackage = require('./fetchPackage') +const findFile = require('./findFile') +const serveFile = require('./serveFile') /** * Creates and returns a function that can be used in the "request" @@ -93,177 +31,17 @@ const createRequestHandler = (options = {}) => { const maximumDepth = options.maximumDepth || Number.MAX_VALUE const blacklist = options.blacklist || [] - const handleRequest = (req, res) => { - let url - try { - url = parsePackageURL(req.url) - } catch (error) { - return sendInvalidURLError(res, req.url) - } + const app = express.Router() - if (url == null) - return sendInvalidURLError(res, req.url) + app.use( + parseURL(), + checkBlacklist(blacklist), + fetchPackage(registryURL), + findFile(), + serveFile(registryURL, autoIndex, maximumDepth) + ) - const { pathname, search, query, packageName, version, filename } = url - const displayName = `${packageName}@${version}` - - const isBlacklisted = blacklist.indexOf(packageName) !== -1 - - if (isBlacklisted) - return sendText(res, 403, `Package ${packageName} is blacklisted`) - - // Step 1: Fetch the package from the registry and store a local copy. - // Redirect if the URL does not specify an exact version number. - const fetchPackage = (next) => { - const packageDir = createTempPath(displayName) - - checkLocalCache(packageDir, (isCached) => { - if (isCached) - return next(packageDir) // Best case: we already have this package on disk. - - // Fetch package info from NPM registry. - getPackageInfo(registryURL, packageName, (error, packageInfo) => { - if (error) - return sendServerError(res, error) - - if (packageInfo == null || packageInfo.versions == null) - return sendNotFoundError(res, `package "${packageName}"`) - - const { versions, 'dist-tags': tags } = packageInfo - - if (version in versions) { - // A valid request for a package we haven't downloaded yet. - const packageConfig = versions[version] - const tarballURL = packageConfig.dist.tarball - - getPackage(tarballURL, packageDir, (error) => { - if (error) { - sendServerError(res, error) - } else { - next(packageDir) - } - }) - } else if (version in tags) { - sendRedirect(res, createPackageURL(packageName, tags[version], filename, search)) - } else { - const maxVersion = maxSatisfyingVersion(Object.keys(versions), version) - - if (maxVersion) { - sendRedirect(res, createPackageURL(packageName, maxVersion, filename, search)) - } else { - sendNotFoundError(res, `package ${displayName}`) - } - } - }) - }) - } - - // Step 2: Determine which file we're going to serve and get its stats. - // Redirect if the request targets a directory with no trailing slash. - const findFile = (packageDir, next) => { - if (filename) { - const path = joinPaths(packageDir, filename) - - // Based on the URL, figure out which file they want. - resolveFile(path, false, (error, file, stats) => { - if (error) { - sendServerError(res, error) - } else if (file == null) { - sendNotFoundError(res, `file "${filename}" in package ${displayName}`) - } else if (stats.isDirectory() && pathname[pathname.length - 1] !== '/') { - // Append `/` to directory URLs - sendRedirect(res, pathname + '/' + search) - } else { - next(file.replace(packageDir, ''), stats) - } - }) - } else { - // No filename in the URL. Try to serve the package's "main" file. - readFile(joinPaths(packageDir, 'package.json'), 'utf8', (error, data) => { - if (error) - return sendServerError(res, error) - - let packageConfig - try { - packageConfig = JSON.parse(data) - } catch (error) { - return sendText(res, 500, `Error parsing ${displayName}/package.json: ${error.message}`) - } - - let mainFilename - const queryMain = query && query.main - - if (queryMain) { - if (!(queryMain in packageConfig)) - return sendNotFoundError(res, `field "${queryMain}" in ${displayName}/package.json`) - - mainFilename = packageConfig[queryMain] - } else { - if (typeof packageConfig.unpkg === 'string') { - // The "unpkg" field allows packages to explicitly declare the - // file to serve at the bare URL (see #59). - mainFilename = packageConfig.unpkg - } else if (typeof packageConfig.browser === 'string') { - // Fall back to the "browser" field if declared (only support strings). - mainFilename = packageConfig.browser - } else { - // If there is no main, use "index" (same as npm). - mainFilename = packageConfig.main || 'index' - } - } - - resolveFile(joinPaths(packageDir, mainFilename), true, (error, file, stats) => { - if (error) { - sendServerError(res, error) - } else if (file == null) { - sendNotFoundError(res, `main file "${mainFilename}" in package ${displayName}`) - } else { - next(file.replace(packageDir, ''), stats) - } - }) - }) - } - } - - // Step 3: Send the file, JSON metadata, or HTML directory listing. - const serveFile = (baseDir, path, stats) => { - if (query.json != null) { - generateMetadata(baseDir, path, stats, maximumDepth, (error, metadata) => { - if (metadata) { - sendJSON(res, metadata, oneYear) - } else { - sendServerError(res, `unable to generate JSON metadata for ${displayName}${filename}`) - } - }) - } else if (stats.isFile()) { - sendFile(res, joinPaths(baseDir, path), stats, oneYear) - } else if (autoIndex && stats.isDirectory()) { - getPackageInfo(registryURL, packageName, (error, packageInfo) => { - if (error) { - sendServerError(res, `unable to generate index page for ${displayName}${filename}`) - } else { - generateDirectoryIndexHTML(packageInfo, version, baseDir, path, (error, html) => { - if (html) { - sendHTML(res, html) - } else { - sendServerError(res, `unable to generate index page for ${displayName}${filename}`) - } - }) - } - }) - } else { - sendInvalidURLError(res, `${displayName}${filename} is a ${getFileType(stats)}`) - } - } - - fetchPackage(packageDir => { - findFile(packageDir, (file, stats) => { - serveFile(packageDir, file, stats) - }) - }) - } - - return handleRequest + return app } module.exports = createRequestHandler diff --git a/server/middleware/parseURL.js b/server/middleware/parseURL.js new file mode 100644 index 0000000..5dcc6b1 --- /dev/null +++ b/server/middleware/parseURL.js @@ -0,0 +1,30 @@ +const { parsePackageURL } = require('./PackageUtils') + +/** + * Parse and validate the URL. + */ +function parseURL() { + return function (req, res, next) { + let url + try { + url = parsePackageURL(req.url) + } catch (error) { + return res.status(403).send(`Invalid URL: ${req.url}`) + } + + if (url == null) + return res.status(403).send(`Invalid URL: ${req.url}`) + + req.packageName = url.packageName + req.packageVersion = url.packageVersion + req.packageSpec = `${req.packageName}@${req.packageVersion}` + req.pathname = url.pathname + req.filename = url.filename + req.search = url.search + req.query = url.query + + next() + } +} + +module.exports = parseURL diff --git a/server/middleware/serveFile.js b/server/middleware/serveFile.js new file mode 100644 index 0000000..922e36d --- /dev/null +++ b/server/middleware/serveFile.js @@ -0,0 +1,45 @@ +const path = require('path') +const { getPackageInfo } = require('./RegistryUtils') +const { generateMetadata } = require('./MetadataUtils') +const { generateDirectoryIndexHTML } = require('./IndexUtils') +const { sendFile } = require('./ResponseUtils') + +/** + * Send the file, JSON metadata, or HTML directory listing. + */ +function serveFile(registryURL, autoIndex, maximumDepth) { + return function (req, res, next) { + // TODO: change query param from "json" => "meta" + if (req.query.json != null) { + generateMetadata(req.packageDir, req.file, req.stats, maximumDepth, function (error, metadata) { + if (metadata) { + res.set('Cache-Control', 'public, max-age=31536000').send(metadata) + } else { + res.status(500).send(`Cannot generate JSON metadata for ${req.packageSpec}${req.filename}`) + } + }) + } else if (req.stats.isFile()) { + // TODO: use res.sendFile instead of our own custom function? + sendFile(res, path.join(req.packageDir, req.file), req.stats, 31536000) + } else if (autoIndex && req.stats.isDirectory()) { + // TODO: re-use packageInfo from fetchPackage middleware + getPackageInfo(registryURL, req.packageName, function (error, packageInfo) { + if (error) { + res.status(500).send(`Cannot generate index page for ${req.packageSpec}${req.filename}`) + } else { + generateDirectoryIndexHTML(packageInfo, req.packageVersion, req.packageDir, req.file, function (error, html) { + if (html) { + res.send(html) + } else { + res.status(500).send(`Cannot generate index page for ${req.packageSpec}${req.filename}`) + } + }) + } + }) + } else { + res.status(403).send(`Cannot serve ${req.packageSpec}${req.filename}; it's not a req.file`) + } + } +} + +module.exports = serveFile