fix: context properties are shared between batched requests (#3491)

* test: context properties are shared between

* try alpha

* feat: update to latest version

* changeset

* smol refactor

* docs format

* chore(dependencies): updated changesets for modified dependencies

---------

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

.changeset/graphql-yoga-3491-dependencies.md

@@ -0,0 +1,7 @@
+---
+'graphql-yoga': patch
+---
+dependencies updates:
+  - Updated dependency [`@whatwg-node/server@^0.9.55`
+    ↗︎](https://www.npmjs.com/package/@whatwg-node/server/v/0.9.55) (from `^0.9.54`, in
+    `dependencies`)

.changeset/pink-snails-thank.md

@@ -0,0 +1,9 @@
+---
+'graphql-yoga': patch
+---
+
+Fix issue where context values being shared between batched requests.
+
+A bug within `@whatwg-node/server` caused properties assigned to a batched requests context to be
+propagated to all other batched requests contexts. It is resolved by updating the dependency of
+`@whatwg-node/server` to `0.9.55`.

packages/graphql-yoga/__tests__/batching.spec.ts

@@ -287,4 +287,51 @@ describe('Batching', () => {
       ],
     });
   });
+
+  it('batching context have different identity and properties are assignments are not shared', async () => {
+    let i = 0;
+    type Context = {
+      i?: number;
+    };
+    const contexts = [] as Array<Context>;
+    const yoga = createYoga({
+      schema: createSchema({ typeDefs: `type Query { _: ID }` }),
+      batching: true,
+      plugins: [
+        {
+          onParams(ctx) {
+            contexts.push(ctx.context);
+          },
+        },
+      ],
+      context() {
+        i = i + 1;
+        return { i };
+      },
+    });
+
+    const response = await yoga.fetch('http://yoga/graphql', {
+      method: 'POST',
+      headers: {
+        accept: 'application/graphql-response+json',
+        'Content-Type': 'application/json',
+      },
+      body: JSON.stringify([{ query: `query A {__typename}` }, { query: `query B {__typename}` }]),
+    });
+    expect(response.status).toBe(200);
+    const result = await response.json();
+    expect(result).toEqual([
+      {
+        data: { __typename: 'Query' },
+      },
+      {
+        data: { __typename: 'Query' },
+      },
+    ]);
+
+    expect(contexts.length).toEqual(2);
+    expect(contexts[0]).not.toBe(contexts[1]);
+    expect(contexts[0].i).toEqual(1);
+    expect(contexts[1].i).toEqual(2);
+  });
 });

packages/graphql-yoga/package.json

@@ -57,7 +57,7 @@
     "@graphql-yoga/logger": "workspace:^",
     "@graphql-yoga/subscription": "workspace:^",
     "@whatwg-node/fetch": "^0.10.1",
-    "@whatwg-node/server": "^0.9.54",
+    "@whatwg-node/server": "^0.9.55",
     "dset": "^3.1.1",
     "lru-cache": "^10.0.0",
     "tslib": "^2.5.2"

packages/graphql-yoga/src/server.ts

@@ -462,17 +462,13 @@ export class YogaServer<
     {
       params,
       request,
-      batched,
     }: {
       params: GraphQLParams;
       request: Request;
-      batched: boolean;
     },
-    serverContext: TServerContext,
+    context: TServerContext,
   ) {
     let result: ExecutionResult | AsyncIterable<ExecutionResult> | undefined;
-    const context: TServerContext & YogaInitialContext =
-      batched === true ? Object.create(serverContext) : serverContext;
 
     try {
       for (const onParamsHook of this.onParamsHooks) {
@@ -492,7 +488,7 @@ export class YogaServer<
 
       if (result == null) {
         const additionalContext =
-          serverContext.request === request
+          context.request === request
             ? {
                 params,
               }
@@ -549,7 +545,7 @@ export class YogaServer<
           result = newResult;
         },
         request,
-        context,
+        context: context as TServerContext & YogaInitialContext,
       });
     }
     return result;
@@ -610,17 +606,15 @@ export class YogaServer<
               {
                 params,
                 request,
-                batched: true,
               },
-              serverContext,
+              Object.create(serverContext),
             ),
           ),
         )
       : this.getResultForParams(
           {
             params: requestParserResult,
             request,
-            batched: false,
           },
           serverContext,
         ))) as ResultProcessorInput;

website/src/pages/docs/features/envelop-plugins.mdx

@@ -172,23 +172,20 @@ tokens etc.
 import { Plugin } from 'graphql-yoga'
 
 function useAuth(): Plugin {
- return {
-  onRequest({ request, fetchAPI, endResponse }) {
-    if (!request.headers.get('authorization')) {
-      endResponse(
-        new fetchAPI.Response(
-          null,
-          {
+  return {
+    onRequest({ request, fetchAPI, endResponse }) {
+      if (!request.headers.get('authorization')) {
+        endResponse(
+          new fetchAPI.Response(null, {
             status: 401,
             headers: {
               'Content-Type': 'application/json'
             }
-          }
+          })
         )
-      )
+      }
     }
   }
- }
 }
 ```