Expose Cors option from vanilla ApolloServer constructor (#1335)

* add cors option to apollo-server's constructor

* docs: add cors option to costructor for apollo-server

* expose CorsOptions from vanilla and express integrations

* Update apollo-server.md

docs/source/api/apollo-server.md

@@ -86,6 +86,10 @@ new ApolloServer({
 
   The persisted queries option can be set to an object containing a `cache` field, which will be used to store the mapping between hash and query string.
 
+* `cors`: <`Object` | `boolean`> ([apollo-server](https://github.com/expressjs/cors#cors))
+
+  Pass the integration-specific CORS options. `false` removes the CORS middleware and `true` uses the defaults. This option is only available to `apollo-server`. For other server integrations, place `cors` inside of `applyMiddleware`.
+
 #### Returns
 
 `ApolloServer`

packages/apollo-server-express/src/index.ts

@@ -21,3 +21,6 @@ export {
   registerServer,
   ServerRegistration,
 } from './ApolloServer';
+
+export { CorsOptions } from 'cors';
+export { OptionsJson } from 'body-parser';

packages/apollo-server/src/index.test.ts

@@ -102,6 +102,26 @@ describe('apollo-server', () => {
       await apolloFetch({ query: '{hello}' });
     });
 
+    it('configures cors', async () => {
+      server = new ApolloServer({
+        typeDefs,
+        resolvers,
+        cors: { origin: 'localhost' },
+      });
+
+      const { url: uri } = await server.listen();
+
+      const apolloFetch = createApolloFetch({ uri }).useAfter(
+        (response, next) => {
+          expect(
+            response.response.headers.get('access-control-allow-origin'),
+          ).to.equal('localhost');
+          next();
+        },
+      );
+      await apolloFetch({ query: '{hello}' });
+    });
+
     it('creates a healthcheck endpoint', async () => {
       server = new ApolloServer({
         typeDefs,

packages/apollo-server/src/index.ts

@@ -5,15 +5,22 @@
 import * as express from 'express';
 import * as http from 'http';
 import * as net from 'net';
-import { ApolloServer as ApolloServerBase } from 'apollo-server-express';
+import {
+  ApolloServer as ApolloServerBase,
+  CorsOptions,
+} from 'apollo-server-express';
+import { Config } from 'apollo-server-core';
 
 export {
   GraphQLUpload,
   GraphQLOptions,
   GraphQLExtension,
   gql,
+  Config,
 } from 'apollo-server-core';
 
+export { CorsOptions } from 'apollo-server-express';
+
 export * from './exports';
 
 export interface ServerInfo {
@@ -27,7 +34,13 @@ export interface ServerInfo {
 }
 
 export class ApolloServer extends ApolloServerBase {
-  private httpServer: http.Server;
+  private httpServer!: http.Server;
+  private cors?: CorsOptions | boolean;
+
+  constructor(config: Config & { cors?: CorsOptions | boolean }) {
+    super(config);
+    this.cors = config && config.cors;
+  }
 
   private createServerInfo(
     server: http.Server,
@@ -78,9 +91,12 @@ export class ApolloServer extends ApolloServerBase {
       app,
       path: '/',
       bodyParserConfig: { limit: '50mb' },
-      cors: {
-        origin: '*',
-      },
+      cors:
+        typeof this.cors !== 'undefined'
+          ? this.cors
+          : {
+              origin: '*',
+            },
     });
 
     this.httpServer = http.createServer(app);