Run batching queries in parallel (#176)

CHANGELOG.md

@@ -1,6 +1,7 @@
 # Changelog
 
 ### VNEXT
+* run batched requests in parallel ([@DxCx](https://github.com/DxCx)) on [#273](https://github.com/apollostack/graphql-server/pull/273)
 * Fix GraphiQL options variables. Issue #193. ([@alanchristensen](https://github.com/alanchristensen)) on
 [PR #255](https://github.com/apollostack/apollo-server/pull/255)
 

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

@@ -74,8 +74,7 @@ export async function runHttpQuery(handlerArguments: Array<any>, request: HttpQu
     requestPayload = [requestPayload];
   }
 
-  let responses: Array<ExecutionResult> = [];
-  for (let requestParams of requestPayload) {
+  const requests: Array<ExecutionResult> = requestPayload.map(requestParams => {
     try {
       let query = requestParams.query;
       if ( isGetRequest ) {
@@ -128,17 +127,18 @@ export async function runHttpQuery(handlerArguments: Array<any>, request: HttpQu
         params = optionsObject.formatParams(params);
       }
 
-      responses.push(await runQuery(params));
+      return runQuery(params);
     } catch (e) {
       // Populate any HttpQueryError to our handler which should
       // convert it to Http Error.
       if ( e.name === 'HttpQueryError' ) {
-        throw e;
+        return Promise.reject(e);
       }
 
-      responses.push({ errors: [formatErrorFn(e)] });
+      return Promise.resolve({ errors: [formatErrorFn(e)] });
     }
-  }
+  });
+  const responses = await Promise.all(requests);
 
   if (!isBatch) {
     const gqlResponse = responses[0];

packages/graphql-server-express/src/apolloServerHttp.test.ts

@@ -154,7 +154,9 @@ const version = 'modern';
 describe(`GraphQL-HTTP (apolloServer) tests for ${version} express`, () => {
   describe('POST functionality', () => {
 
-    it('allows gzipped POST bodies', async () => {
+    it('allows gzipped POST bodies', async function () {
+      // Increase timeout for slow node 4
+      this.timeout(3000);
       const app = express();
 
       app.use(urlString(), bodyParser.json());
@@ -181,7 +183,9 @@ describe(`GraphQL-HTTP (apolloServer) tests for ${version} express`, () => {
       });
     });
 
-    it('allows deflated POST bodies', async () => {
+    it('allows deflated POST bodies', async function () {
+      // Increase timeout for slow node 4
+      this.timeout(3000);
       const app = express();
 
       app.use(urlString(), bodyParser.json());

packages/graphql-server-integration-testsuite/src/index.ts

@@ -7,6 +7,7 @@ import {
     GraphQLSchema,
     GraphQLObjectType,
     GraphQLString,
+    GraphQLInt,
     GraphQLError,
     GraphQLNonNull,
     introspectionQuery,
@@ -29,6 +30,17 @@ const queryType = new GraphQLObjectType({
                 return 'it works';
             },
         },
+        testStringWithDelay: {
+            type: GraphQLString,
+            args: {
+              delay: { type: new GraphQLNonNull(GraphQLInt) },
+            },
+            resolve(root, args) {
+              return new Promise((resolve, reject) => {
+                setTimeout(() => resolve('it works'), args['delay']);
+              });
+            },
+        },
         testContext: {
             type: GraphQLString,
             resolve(_, args, context) {
@@ -457,6 +469,29 @@ export default (createApp: CreateAppFunc, destroyApp?: DestroyAppFunc) => {
           });
       });
 
+       it('can handle batch requests in parallel', function() {
+         // this test will fail due to timeout if running serially.
+         const parallels = 100;
+         const delayPerReq = 40;
+         this.timeout(3000);
+
+         app = createApp();
+         const expected = Array(parallels).fill({
+           data: { testStringWithDelay: 'it works' },
+         });
+         const req = request(app)
+           .post('/graphql')
+           .send(Array(parallels).fill({
+             query: `query test($delay: Int!) { testStringWithDelay(delay: $delay) }`,
+             operationName: 'test',
+             variables: { delay: delayPerReq },
+           }));
+           return req.then((res) => {
+             expect(res.status).to.equal(200);
+             return expect(res.body).to.deep.equal(expected);
+           });
+      });
+
       it('clones batch context', () => {
           app = createApp({graphqlOptions: {
               schema,