TODO(AS4) squashing (#6936)

Address a number of v4-related TODOS.

Most notably (copied from changesets):
* Update executeOperation second parameter to be an optional options
object which includes an optional `contextValue`.
* `HTTPGraphQLRequest` now uses a specific `HeaderMap` class which we
export instead of allowing a standard `Map`. The `HeaderMap` downcases
all incoming keys, as header names are not case-sensitive.
* Update `validationRules` typing for correctness. This is sort of a
breaking change for TS users in that the types were more permissive than
they should have been. All `validationRules` list items should conform
to the `graphql-js` `ValidationRule` type.
* Add test for batch requests with no elements (this potentially affects
integration testsuite users)

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.changeset/big-kiwis-explain.md

@@ -0,0 +1,5 @@
+---
+'@apollo/server': patch
+---
+
+Update executeOperation second parameter to be an optional options object which includes an optional `contextValue`.

.changeset/healthy-deers-search.md

@@ -0,0 +1,5 @@
+---
+'@apollo/server': patch
+---
+
+`HTTPGraphQLRequest` now uses a specific `HeaderMap` class which we export instead of allowing a standard `Map`. The `HeaderMap` downcases all incoming keys, as header names are not case-sensitive.

.changeset/late-numbers-pull.md

@@ -0,0 +1,5 @@
+---
+'@apollo/server': patch
+---
+
+Update `validationRules` typing for correctness. This is sort of a breaking change for TS users in that the types were more permissive than they should have been. All `validationRules` list items should conform to the `graphql-js` `ValidationRule` type.

.changeset/witty-moles-fail.md

@@ -0,0 +1,5 @@
+---
+'@apollo/server-integration-testsuite': patch
+---
+
+Add test for batch requests with no elements

docs/source/api/apollo-server.mdx

@@ -330,6 +330,8 @@ An object containing configuration options for connecting Apollo Server to [Apol
 
 Controls whether to allow [Batching Queries](../workflow/requests/#batching) in a single HTTP Request. Defaults to `false`. If a request comes in formatted as an array rather than as a single request object, an error will be thrown ( i.e., `Operation batching disabled`) _unless_ batching is enabled.
 
+> Note: In the case of duplicate response headers across separate requests, the later request's header will take precedence on a per-header basis.
+
 </td>
 </tr>
 
@@ -599,7 +601,7 @@ The `executeOperation` method takes two arguments:
 
 - The first argument is an object describing the GraphQL operation to be executed.
   - Supported fields are listed in the table below.
-- The second optional argument is used as the operation's [context value](../data/resolvers/#the-context-argument). Note, this argument is only optional if your server _doesn't_ expect a context value (i.e., your server uses the default context because you didn't explicitly provide another one).
+- The second argument is the optional options object. This object includes the operation's optional [`contextValue`](../data/resolvers/#the-context-argument). Note, this argument is only optional if your server _doesn't_ expect a context value (i.e., your server uses the default context because you didn't explicitly provide another one).
 
 The `response` object returned from `executeOperation` is a `GraphQLResponse`, which has `body` and `http` fields.
 

docs/source/migration.mdx

@@ -1119,7 +1119,7 @@ So a test for Apollo Server 3 that looks like this:
 
 <MultiCodeBlock>
 
-```ts {13-17}
+```ts
 const server = new ApolloServer({
   typeDefs: "type Query { hello: String!}",
   resolvers: {
@@ -1133,9 +1133,13 @@ const server = new ApolloServer({
 const result = await server.executeOperation({
   query: 'query helloContext { hello }',
 }, {
-  // A half-hearted attempt at making something vaguely like an express.Request,
-  // and not bothering to make the express.Response at all.
-  req: { headers: { name: 'world' } },
+  // highlight-start
+  contextValue: {
+    // A half-hearted attempt at making something vaguely like an express.Request,
+    // and not bothering to make the express.Response at all.
+    req: { headers: { name: 'world' } },
+  }
+  // highlight-end
 });
 
 expect(result.data?.hello).toBe('Hello world!'); // -> true
@@ -1147,7 +1151,7 @@ looks like this in Apollo Server 4:
 
 <MultiCodeBlock>
 
-```ts {16-18}
+```ts
 interface MyContext {
   name: string;
 }
@@ -1164,7 +1168,11 @@ const server = new ApolloServer<MyContext>({
 const { body } = await server.executeOperation({
   query: 'query helloContext { hello }',
 }, {
-  name: 'world',
+  // highlight-start
+  contextValue: {
+    name: 'world',
+  }
+  // highlight-end
 });
 
 // Note the use of Node's assert rather than Jest's expect; if using
@@ -1676,6 +1684,10 @@ const { url } = await startStandaloneServer(apolloServerInstance, {
 });
 ```
 
+### Improved typing for `validationRules`
+
+In Apollo Server 3, the `validationRules` option was declared as a list of functions that returned `any`. However, at runtime the functions actually needed to return a `graphql-js` `ASTVisitor`. In Apollo Server 4, the TypeScript type ensures that `validationRules` is a list of `graphql-js` `ValidationRule`s. If your `validationRules` has a TypeScript error, you will need to fix one or more of your rules to correctly return `ASTVisitor`s.
+
 ### `@apollo/utils.fetcher` replaces `apollo-server-env`
 
 In Apollo Server 3, the `apollo-server-env` package primarily provides TypeScript typings and polyfills for the `fetch` and `URL` APIs.

docs/source/testing/testing.mdx

@@ -103,8 +103,17 @@ it('fetches single launch', async () => {
       query: GET_LAUNCH,
       variables: { id: 1 },
     },
-    // this second argument is used as the context for our operation
-    { user: { id: 1, email: 'a@a.a' }, dataSources: { userAPI, launchAPI } }, //highlight-line
+    {
+      // highlight-start
+      contextValue: {
+        user: { id: 1, email: 'a@a.a' },
+        dataSources: {
+          userAPI,
+          launchAPI,
+        },
+      },
+      // highlight-end
+    },
   );
 
   expect(res).toMatchSnapshot();

docs/source/workflow/requests.md

@@ -67,6 +67,8 @@ If you have enabled HTTP batching, you can send a batch of queries in a single `
 
 If you send a batched request, Apollo Server responds with a corresponding array of GraphQL responses.
 
+> Note: In the case of duplicate response headers across separate requests, the later request's header will take precedence on a per-header basis.
+
 ## GET requests
 
 Apollo Server also accepts `GET` requests for queries (but not mutations). With a `GET` request, query details (`query`, `operationName`, `variables`) are provided as URL query parameters. The `variables` option is a URL-escaped JSON object.

packages/integration-testsuite/.npmignore

@@ -1,5 +1,4 @@
 *
-node_modules/**/*
 !src/**/*
 !dist/**/*
 !package.json

packages/integration-testsuite/src/apolloServerTests.ts

@@ -13,10 +13,9 @@ import {
   GraphQLString,
   GraphQLError,
   ValidationContext,
-  FieldDefinitionNode,
-  ResponsePath,
   DocumentNode,
   printSchema,
+  FieldNode,
 } from 'graphql';
 
 // Note that by doing deep imports here we don't need to install React.
@@ -29,11 +28,12 @@ import {
   ApolloFetch,
   ParsedResponse,
 } from './apolloFetch.js';
-import type {
+import {
   ApolloServerOptions,
   ApolloServer,
   BaseContext,
   ApolloServerPlugin,
+  HeaderMap,
 } from '@apollo/server';
 import fetch, { type Headers } from 'node-fetch';
 
@@ -209,7 +209,7 @@ export function defineIntegrationTestSuiteApolloServerTests(
       describe('validation rules', () => {
         it('accepts additional rules', async () => {
           const NoTestString = (context: ValidationContext) => ({
-            Field(node: FieldDefinitionNode) {
+            Field(node: FieldNode) {
               if (node.name.value === 'testString') {
                 context.reportError(
                   new GraphQLError('Not allowed to use', { nodes: [node] }),
@@ -538,12 +538,11 @@ export function defineIntegrationTestSuiteApolloServerTests(
     describe('Plugins', () => {
       let apolloFetch: ApolloFetch;
       let apolloFetchResponse: ParsedResponse;
-      let serverInstance: ApolloServer<BaseContext>;
 
       const setupApolloServerAndFetchPairForPlugins = async (
         plugins: ApolloServerPlugin<BaseContext>[] = [],
       ) => {
-        const { server, url } = await createServer(
+        const { url } = await createServer(
           {
             typeDefs: gql`
               type Query {
@@ -555,8 +554,6 @@ export function defineIntegrationTestSuiteApolloServerTests(
           { context: async () => ({ customContext: true }) },
         );
 
-        serverInstance = server;
-
         apolloFetch = createApolloFetch({ uri: url })
           // Store the response so we can inspect it.
           .useAfter(({ response }, next) => {
@@ -565,64 +562,6 @@ export function defineIntegrationTestSuiteApolloServerTests(
           });
       };
 
-      // TODO(AS4): Is this test still relevant now that we pass
-      // the context explicitly to executeOperation?
-      // Test for https://github.com/apollographql/apollo-server/issues/4170
-      it('works when using executeOperation', async () => {
-        const encounteredFields: ResponsePath[] = [];
-        const encounteredContext: BaseContext[] = [];
-        await setupApolloServerAndFetchPairForPlugins([
-          {
-            requestDidStart: async () => ({
-              executionDidStart: async () => ({
-                willResolveField({ info, contextValue }) {
-                  encounteredFields.push(info.path);
-                  encounteredContext.push(contextValue);
-                },
-              }),
-            }),
-          },
-        ]);
-
-        // The bug in 4170 (linked above) was occurring because of a failure
-        // to clone context in `executeOperation` in the same way that occurs
-        // in `runHttpQuery` prior to entering the request pipeline.  That
-        // resulted in the inability to attach a symbol to the context because
-        // the symbol already existed on the context.  Of course, a context
-        // is only created after the first invocation, so we'll run this twice
-        // to encounter the error where it was in the way when we tried to set
-        // it the second time.  While we could have tested for the property
-        // before assigning to it, that is not the contract we have with the
-        // context, which should have been copied on `executeOperation` (which
-        // is meant to be used by testing, currently).
-        await serverInstance.executeOperation(
-          {
-            query: '{ justAField }',
-          },
-          { customContext: true },
-        );
-        await serverInstance.executeOperation(
-          {
-            query: '{ justAField }',
-          },
-          { customContext: true },
-        );
-
-        expect(encounteredFields).toStrictEqual([
-          { key: 'justAField', prev: undefined, typename: 'Query' },
-          { key: 'justAField', prev: undefined, typename: 'Query' },
-        ]);
-
-        // This bit is just to ensure that nobody removes `context` from the
-        // `setupApolloServerAndFetchPairForPlugins` thinking it's unimportant.
-        // When a custom context is not provided, a new one is initialized
-        // on each request.
-        expect(encounteredContext).toStrictEqual([
-          expect.objectContaining({ customContext: true }),
-          expect.objectContaining({ customContext: true }),
-        ]);
-      });
-
       it('returns correct status code for a normal operation', async () => {
         await setupApolloServerAndFetchPairForPlugins();
 
@@ -1664,9 +1603,15 @@ export function defineIntegrationTestSuiteApolloServerTests(
 
             expect(spy).not.toBeCalled();
 
-            await server.executeOperation({ query: '{hello}' }, uniqueContext);
+            await server.executeOperation(
+              { query: '{hello}' },
+              { contextValue: uniqueContext },
+            );
             expect(spy).toHaveBeenCalledTimes(1);
-            await server.executeOperation({ query: '{hello}' }, uniqueContext);
+            await server.executeOperation(
+              { query: '{hello}' },
+              { contextValue: uniqueContext },
+            );
             expect(spy).toHaveBeenCalledTimes(2);
           });
         });
@@ -1847,7 +1792,7 @@ export function defineIntegrationTestSuiteApolloServerTests(
                     extensions: {
                       http: {
                         status: 404,
-                        headers: new Map([['special', 'hello']]),
+                        headers: new HeaderMap([['special', 'hello']]),
                       },
                     },
                   }),

packages/integration-testsuite/src/httpServerTests.ts

@@ -35,6 +35,7 @@ import type {
   GraphQLRequestListener,
   PersistedQueryOptions,
 } from '@apollo/server';
+import { HeaderMap } from '@apollo/server';
 import { ApolloServerPluginCacheControl } from '@apollo/server/plugin/cacheControl';
 import { ApolloServerPluginCacheControlDisabled } from '@apollo/server/plugin/disabled';
 import {
@@ -202,7 +203,7 @@ const queryType = new GraphQLObjectType({
       resolve() {
         throw new GraphQLError('error 2', {
           extensions: {
-            http: { headers: new Map([['erroneous', 'indeed']]) },
+            http: { headers: new HeaderMap([['erroneous', 'indeed']]) },
           },
         });
       },
@@ -212,7 +213,7 @@ const queryType = new GraphQLObjectType({
       resolve() {
         throw new GraphQLError('error 3', {
           extensions: {
-            http: { headers: new Map([['felonious', 'nah']]) },
+            http: { headers: new HeaderMap([['felonious', 'nah']]) },
           },
         });
       },
@@ -1211,6 +1212,26 @@ export function defineIntegrationTestSuiteHttpServerTests(
         });
       });
 
+      it('returns an error on batch requests with no elements', async () => {
+        const app = await createApp({ schema, allowBatchedHttpRequests: true });
+        const req = request(app).post('/').send([]);
+        return req.then((res) => {
+          expect(res.status).toEqual(400);
+          expect(res.body).toMatchInlineSnapshot(`
+            {
+              "errors": [
+                {
+                  "extensions": {
+                    "code": "BAD_REQUEST",
+                  },
+                  "message": "No operations found in request.",
+                },
+              ],
+            }
+          `);
+        });
+      });
+
       it('can handle batch requests in parallel', async function () {
         const parallels = 100;
         const delayPerReq = 40;

packages/plugin-response-cache/src/ApolloServerPluginResponseCache.ts

@@ -1,10 +1,11 @@
 import type { CacheHint } from '@apollo/cache-control-types';
-import type {
+import {
   ApolloServerPlugin,
   BaseContext,
   GraphQLRequestContext,
   GraphQLRequestListener,
   GraphQLResponse,
+  HeaderMap,
 } from '@apollo/server';
 import { createHash } from '@apollo/utils.createhash';
 import {
@@ -220,7 +221,7 @@ export default function plugin<TContext extends BaseContext>(
               body: { kind: 'single', singleResult: { data: value.data } },
               http: {
                 status: undefined,
-                headers: new Map(),
+                headers: new HeaderMap(),
               },
             };
           }

packages/server/.npmignore

@@ -1,8 +1,6 @@
 *
 # Include the package.json files that give us deep imports.
 !**/package.json
-# TODO(AS4): glasser isn't this covered by the * above?
-node_modules/**/*
 !src/**/*
 src/**/__tests__/**
 !dist/**/*