use playground default settings when possible

CHANGELOG.md

@@ -27,6 +27,7 @@ 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)
+- playground would use its own settings as default [#1516](https://github.com/apollographql/apollo-server/pull/1516)
 - Lambda: Look in event.path first when picking endpoint for GraphQL Playground [#1527](https://github.com/apollographql/apollo-server/pull/1527)
 - Fix to allow enabling GraphQL Playground in production with custom config [#1495](https://github.com/apollographql/apollo-server/pull/1495)
 

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

@@ -49,13 +49,19 @@ export function createPlaygroundOptions(
   const playgroundOverrides =
     typeof playground === 'boolean' ? {} : playground || {};
 
+  const settingsOverrides = playgroundOverrides.hasOwnProperty('settings')
+    ? {
+        settings: {
+          ...defaultPlaygroundOptions.settings,
+          ...playgroundOverrides.settings,
+        },
+      }
+    : { settings: undefined };
+
   const playgroundOptions: PlaygroundRenderPageOptions = {
     ...defaultPlaygroundOptions,
     ...playgroundOverrides,
-    settings: {
-      ...defaultPlaygroundOptions.settings,
-      ...playgroundOverrides.settings,
-    },
+    ...settingsOverrides,
   };
 
   return playgroundOptions;

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

@@ -171,6 +171,7 @@ describe('apollo-server-express', () => {
               reject(error);
             } else {
               expect(body).toMatch('GraphQLPlayground');
+              expect(body).not.toMatch('settings');
               expect(response.statusCode).toEqual(200);
               resolve();
             }