Feat: Added CORS to config (#302)

Author: adampash

examples/social-network/config/environments/development.js

@@ -1,4 +1,25 @@
 export default {
+  server: {
+    cors: {
+      origin: '*',
+      enabled: true,
+
+      headers: [
+        'Accept',
+        'Content-Type'
+      ],
+
+      methods: [
+        'GET',
+        'POST',
+        'PATCH',
+        'DELETE',
+        'HEAD',
+        'OPTIONS'
+      ]
+    }
+  },
+
   logging: {
     level: 'DEBUG',
     format: 'text',

src/packages/application/initialize.js

@@ -20,7 +20,8 @@ export default async function initialize<T: Application>(app: T, {
   path,
   port,
   logging,
-  database
+  database,
+  server: serverConfig
 }: Application$opts) {
   const routes = loader(path, 'routes');
   const models = loader(path, 'models');
@@ -103,7 +104,8 @@ export default async function initialize<T: Application>(app: T, {
 
   const server = new Server({
     router,
-    logger
+    logger,
+    ...serverConfig
   });
 
   if (!LUX_CONSOLE) {

src/packages/config/index.js

@@ -8,6 +8,11 @@ export function createDefaultConfig(): Config {
   const isProdENV = NODE_ENV === 'production';
 
   return {
+    server: {
+      cors: {
+        enabled: false
+      }
+    },
     logging: {
       level: isProdENV ? 'INFO' : 'DEBUG',
       format: isProdENV ? 'json' : 'text',

src/packages/config/interfaces.js

@@ -1,6 +1,8 @@
 // @flow
 import type { Logger$config } from '../logger';
+import type { Server$config } from '../server';
 
 export type Config = {
   logging: Logger$config;
+  server: Server$config;
 };

src/packages/server/index.js

@@ -10,13 +10,14 @@ import { createResponder } from './responder';
 import { tryCatchSync } from '../../utils/try-catch';
 import validateAccept from './utils/validate-accept';
 import validateContentType from './utils/validate-content-type';
+import setCORSHeaders from './utils/set-cors-headers';
 
 import type { Writable } from 'stream';
 import type { IncomingMessage, Server as HTTPServer } from 'http';
 
 import type { Request } from './request/interfaces';
 import type { Response } from './response/interfaces';
-import type { Server$opts } from './interfaces';
+import type { Server$opts, Server$config } from './interfaces';
 
 /**
  * @private
@@ -26,9 +27,11 @@ class Server {
 
   router: Server$opts.router;
 
+  cors: Server$config.cors;
+
   instance: HTTPServer;
 
-  constructor({ logger, router }: Server$opts) {
+  constructor({ logger, router, cors }: Server$opts) {
     Object.defineProperties(this, {
       router: {
         value: router,
@@ -44,6 +47,13 @@ class Server {
         configurable: false
       },
 
+      cors: {
+        value: cors,
+        writable: false,
+        enumerable: false,
+        configurable: false
+      },
+
       instance: {
         value: createServer(this.receiveRequest),
         writable: false,
@@ -58,19 +68,22 @@ class Server {
   }
 
   initializeRequest(req: IncomingMessage, res: Writable): [Request, Response] {
-    const { logger, router } = this;
+    const { logger, router, cors } = this;
 
     req.setEncoding('utf8');
 
-    return [
-      createRequest(req, {
-        logger,
-        router
-      }),
-      createResponse(res, {
-        logger
-      })
-    ];
+    const response = createResponse(res, {
+      logger
+    });
+
+    setCORSHeaders(response, cors);
+
+    const request = createRequest(req, {
+      logger,
+      router
+    });
+
+    return [request, response];
   }
 
   validateRequest({ method, headers }: Request): true {
@@ -122,6 +135,8 @@ export default Server;
 export { getDomain } from './request';
 export { default as createServerError } from './utils/create-server-error';
 
+export type { Server$config } from './interfaces';
+
 export type {
   Request,
   Request$params,

src/packages/server/interfaces.js

@@ -2,7 +2,18 @@
 import type Logger from '../logger';
 import type Router from '../router';
 
-export type Server$opts = {
+export type Server$cors = {
+  enabled: boolean;
+  origin?: string;
+  headers?: Array<string>;
+  methods?: Array<string>;
+};
+
+export type Server$config = {
+  cors: Server$cors;
+};
+
+export type Server$opts = Server$config & {
   logger: Logger;
   router: Router;
 };

src/packages/server/utils/set-cors-headers.js

@@ -0,0 +1,26 @@
+// @flow
+import type { Response } from '../index';
+import type { Server$cors } from '../interfaces';
+
+export default function setCORSHeaders(res: Response, {
+  origin,
+  methods,
+  headers,
+  enabled
+}: Server$cors) {
+  if (!enabled) {
+    return;
+  }
+
+  if (origin) {
+    res.setHeader('Access-Control-Allow-Origin', origin);
+  }
+
+  if (methods) {
+    res.setHeader('Access-Control-Allow-Methods', methods.join());
+  }
+
+  if (headers) {
+    res.setHeader('Access-Control-Allow-Headers', headers.join());
+  }
+}