Cleanup

src/allowed-method.ts

@@ -0,0 +1,41 @@
+import { IncomingMessage, ServerResponse } from 'micri';
+import { sendError } from './error';
+
+// These methods are allowd for static resources: files and folder listings.
+const ALLOW_METHODS = ['GET', 'HEAD', 'OPTIONS'];
+const ALLOW_METHODS_STR = ALLOW_METHODS.join(', ');
+
+const ALLOW_ORIGIN = '*';
+const ALLOW_REQ_HEADERS = 'Accept, Accept-Encoding, Range';
+const EXPOSE_RES_HEADERS =
+	'Accept-Ranges, Content-Range, Content-Length, Content-Type, Content-Encoding, Content-Disposition, Date, ETag, Transfer-Encoding, Server';
+
+/**
+ * Check that the request method is one of the allowed types for static resources.
+ */
+export default function allowedMethod(req: IncomingMessage, res: ServerResponse): boolean {
+	if (!ALLOW_METHODS.includes(req.method || '')) {
+		res.setHeader('Allow', ALLOW_METHODS_STR);
+		sendError(req, res, 405, {
+			code: 'method_not_allowed',
+			message: 'Method not allowed',
+		});
+
+		return false;
+	}
+
+	if (req.method === 'OPTIONS') {
+		res.writeHead(204, {
+			'Access-Control-Allow-Origin': ALLOW_ORIGIN,
+			'Access-Control-Allow-Methods': ALLOW_METHODS_STR,
+			'Access-Control-Allow-Headers': ALLOW_REQ_HEADERS,
+			'Access-Control-Expose-Headers': EXPOSE_RES_HEADERS,
+			'Access-Control-Max-Age': '86400',
+		});
+		res.end();
+
+		return false;
+	}
+
+	return true;
+}

src/fetch-graph-api.ts

@@ -11,6 +11,19 @@ type OauthToken = {
 	access_token: string;
 };
 
+class GraphApiError extends Error {
+	method: string;
+	path: string;
+	responseBody: string;
+
+	constructor(path: string, opts: FetchOptions, res: Response, body: string, message: string) {
+		super(`${message} (${res.statusText})`);
+		this.method = opts.method || 'GET';
+		this.path = path;
+		this.responseBody = body;
+	}
+}
+
 const RESOURCE = 'https://graph.microsoft.com/';
 const [TENANT_ID, CLIENT_ID, CLIENT_SECRET] = getEnv('TENANT_ID', 'CLIENT_ID', 'CLIENT_SECRET');
 let tokenPromise: Promise<OauthToken> | null;
@@ -28,19 +41,6 @@ async function getToken(): Promise<OauthToken> {
 	return res.json();
 }
 
-class GraphApiError extends Error {
-	method: string;
-	path: string;
-	responseBody: string;
-
-	constructor(path: string, opts: FetchOptions, res: Response, body: string, message: string) {
-		super(`${message} (${res.statusText})`);
-		this.method = opts.method || 'GET';
-		this.path = path;
-		this.responseBody = body;
-	}
-}
-
 export default async function fetchAPI(path: string, opts: FetchOptions = {}) {
 	if (!tokenPromise) {
 		tokenPromise = getToken();

src/get-site-config.ts

@@ -7,6 +7,9 @@ import { DirectoryListing, File, Folder } from './graph-api-types';
 
 const [ROOT] = getEnv('ROOT');
 
+/**
+ * SiteConfig can be set per each domain.
+ */
 export type SiteConfig = {
 	/**
 	 * Custom error page file paths.

src/index.ts

@@ -9,33 +9,30 @@ import serveUri from './serve-uri';
 import { sendError } from './error';
 
 const [ROOT] = getEnv('ROOT');
+const HOSTNAME_RE = /^(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9])$/;
 
 const server = micri(async (req: IncomingMessage, res: ServerResponse) => {
 	accesslog(req, res);
 
-	const url = parse(req.url || '/', true);
+	const pathname = parse(req.url || '/', true).pathname || '';
 	const host = req.headers.host?.split(':')[0] || '';
 
-	if (
-		host === '' ||
-		!/^(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9])$/.test(
-			host
-		)
-	) {
+	if (host === '' || !HOSTNAME_RE.test(host)) {
 		return sendError(req, res, 400, {
 			code: 'invalid_host',
 			message: 'Invalid Host',
 		});
 	}
 
 	const siteConfig = await getSiteConfig(host);
-	return serveUri(req, res, host, url.pathname || '', siteConfig);
+	return serveUri(req, res, host, pathname, siteConfig);
 });
 
 server.listen(process.env.PORT || 3000);
 
+// Start authentication on startup to minimize the effect to serving traffic.
 apiFetch(`${ROOT}:`)
-	.then(() => console.log(`Authenticated`)) // eslint-disable-line no-console
+	.then(() => console.log('Authenticated')) // eslint-disable-line no-console
 	.catch((err: Error) => {
 		console.error(err); // eslint-disable-line no-console
 		process.exit(1);

src/send-file-list.ts

@@ -1,10 +1,13 @@
 import { send, IncomingMessage, ServerResponse } from 'micri';
 import { parseAll } from '@hapi/accept';
-import allowMethods from './allow-methods';
+import allowedMethod from './allowed-method';
 import setVary from './set-vary';
 import { File, Folder } from './graph-api-types';
 
-function getParent(path: string) {
+/**
+ * Get path to the parent folder of path.
+ */
+function getParent(path: string): string {
 	const prev = path.split('/').slice(0, -1).join('/');
 
 	return prev.length === 0 ? '/' : prev;
@@ -42,12 +45,12 @@ export default function sendFileList(
 	res: ServerResponse,
 	pathname: string,
 	files: Array<File | Folder>
-) {
+): void {
 	let types = ['*/*'];
 
 	// Some methods are not allowed here and some will need special
 	// handling.
-	if (!allowMethods(req, res)) {
+	if (!allowedMethod(req, res)) {
 		return;
 	}
 

src/send-file.ts

@@ -1,6 +1,6 @@
 import { createHash } from 'crypto';
 import { IncomingMessage, ServerResponse, send } from 'micri';
-import allowMethods from './allow-methods';
+import allowedMethod from './allowed-method';
 import fetch from './fetch';
 import setVary from './set-vary';
 import { CACHE_CONTROL } from './config';
@@ -22,10 +22,10 @@ function makeReqHeaders(req: IncomingMessage) {
 	return headers;
 }
 
-export default async function sendFile(req: IncomingMessage, res: ServerResponse, file: File) {
+export default async function sendFile(req: IncomingMessage, res: ServerResponse, file: File): Promise<void> {
 	// Some methods are not allowed here and some will need special
 	// handling.
-	if (!allowMethods(req, res)) {
+	if (!allowedMethod(req, res)) {
 		return;
 	}
 

src/set-vary.ts

@@ -1,3 +1,3 @@
 import { ServerResponse } from 'micri';
 
-export default (res: ServerResponse) => res.setHeader('Vary', 'Accept, Accept-Encoding, Range');
+export default (res: ServerResponse): void => res.setHeader('Vary', 'Accept, Accept-Encoding, Range');