Fixed GraphQL Playground with custom configuration in production.

CHANGELOG.md

@@ -7,6 +7,7 @@ All of the packages in the `apollo-server` repo are released with the same versi
 - express, koa: remove next after playground [#1436](https://github.com/apollographql/apollo-server/pull/1436)
 - Hapi: Pass the response toolkit to the context function. [#1407](https://github.com/apollographql/apollo-server/pull/1407)
 - update apollo-engine-reporting-protobuf to non-beta [#1429](https://github.com/apollographql/apollo-server/pull/1429)
+- Fix to allow enabling GraphQL Playground in production with custom config [#1495](https://github.com/apollographql/apollo-server/pull/1495)
 
 ### rc.10
 

packages/apollo-server-core/src/playground.ts

@@ -39,7 +39,8 @@ export function createPlaygroundOptions(
   playground: PlaygroundConfig = {},
 ): PlaygroundRenderPageOptions | undefined {
   const isDev = process.env.NODE_ENV !== 'production';
-  const enabled: boolean = typeof playground === 'boolean' ? playground : isDev;
+  const enabled: boolean =
+    typeof playground !== 'undefined' ? !!playground : isDev;
 
   if (!enabled) {
     return undefined;

packages/apollo-server-express/src/__tests__/ApolloServer.test.ts

@@ -181,7 +181,7 @@ describe('apollo-server-express', () => {
 
     it('accepts partial GraphQL Playground Options', async () => {
       const nodeEnv = process.env.NODE_ENV;
-      delete process.env.NODE_ENV;
+      process.env.NODE_ENV = 'production';
 
       const defaultQuery = 'query { foo { bar } }';
       const endpoint = '/fumanchupacabra';