Update to TypeScript 3.1

package-lock.json

@@ -12470,9 +12470,9 @@
       "dev": true
     },
     "typescript": {
-      "version": "3.0.3",
-      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.0.3.tgz",
-      "integrity": "sha512-kk80vLW9iGtjMnIv11qyxLqZm20UklzuR2tL0QAnDIygIUIemcZMxlMWudl9OOt76H3ntVzcTiddQ1/pAAJMYg==",
+      "version": "3.1.1",
+      "resolved": "https://registry.npmjs.org/typescript/-/typescript-3.1.1.tgz",
+      "integrity": "sha512-Veu0w4dTc/9wlWNf2jeRInNodKlcdLgemvPsrNpfu5Pq39sgfFjvIIgTsvUHCoLBnMhPoUA+tFxsXjU6VexVRQ==",
       "dev": true
     },
     "uglify-js": {

package.json

@@ -113,7 +113,7 @@
     "test-listen": "1.1.0",
     "ts-jest": "23.1.4",
     "tslint": "5.11.0",
-    "typescript": "3.0.3",
+    "typescript": "3.1.1",
     "ws": "6.0.0",
     "yup": "0.26.5"
   },

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

@@ -313,7 +313,7 @@ export async function runHttpQuery(
         context = {} as Record<string, any>;
       } else if (typeof context === 'function') {
         try {
-          context = await context();
+          context = await (context as Function)();
         } catch (e) {
           e.message = `Context creation failed: ${e.message}`;
           // For errors that are not internal, such as authentication, we
@@ -342,11 +342,14 @@ export async function runHttpQuery(
 
         for (const dataSource of Object.values(dataSources)) {
           if (dataSource.initialize) {
-            dataSource.initialize({ context, cache: optionsObject.cache! });
+            dataSource.initialize({
+              context: context!,
+              cache: optionsObject.cache!,
+            });
           }
         }
 
-        if ('dataSources' in context) {
+        if ('dataSources' in context!) {
           throw new Error(
             'Please use the dataSources config option instead of putting dataSources on the context yourself.',
           );

packages/graphql-extensions/src/index.ts

@@ -20,7 +20,7 @@ export type EndHandler = (...errors: Array<Error>) => void;
 // arguments.
 type StartHandlerInvoker<TContext = any> = (
   ext: GraphQLExtension<TContext>,
-) => void;
+) => EndHandler | void;
 
 // Copied from runQuery in apollo-server-core.
 // XXX Will this work properly if it's an identical interface of the