perf(graphql): cache internal core module lookup

packages/apollo/tests/e2e/request-scoped.spec.ts

@@ -80,6 +80,14 @@ describe('Request scope', () => {
       expect(Guard.COUNTER).toEqual(3);
       expect(Guard.REQUEST_SCOPED_DATA).toEqual([1, 1, 1]);
     });
+
+    it(`should inject REQUEST context into request-scoped services`, async () => {
+      expect(UsersService.REQUEST_CONTEXTS).toHaveLength(3);
+      UsersService.REQUEST_CONTEXTS.forEach((context) => {
+        expect(context).toBeDefined();
+        expect(context.req).toBeDefined();
+      });
+    });
   });
 
   afterAll(async () => {

packages/apollo/tests/graphql/hello/users/users.service.ts

@@ -1,10 +1,17 @@
 import { Inject, Injectable, Scope } from '@nestjs/common';
+import { CONTEXT } from '@nestjs/graphql';
 
 @Injectable({ scope: Scope.REQUEST })
 export class UsersService {
   static COUNTER = 0;
-  constructor(@Inject('META') private readonly meta) {
+  static REQUEST_CONTEXTS: any[] = [];
+
+  constructor(
+    @Inject('META') private readonly meta,
+    @Inject(CONTEXT) private readonly context: any,
+  ) {
     UsersService.COUNTER++;
+    UsersService.REQUEST_CONTEXTS.push(this.context);
   }
 
   findById(id: string) {

packages/graphql/lib/services/resolvers-explorer.service.ts

@@ -48,6 +48,7 @@ export class ResolversExplorerService extends BaseExplorerService {
   private readonly logger = new Logger(ResolversExplorerService.name);
   private readonly gqlParamsFactory = new GqlParamsFactory();
   private readonly injector = new Injector();
+  private coreModuleRef: Module | null | undefined;
 
   constructor(
     private readonly modulesContainer: ModulesContainer,
@@ -298,18 +299,22 @@ export class ResolversExplorerService extends BaseExplorerService {
   }
 
   private registerContextProvider<T = any>(request: T, contextId: ContextId) {
-    const coreModuleArray = [...this.modulesContainer.entries()]
-      .filter(
-        ([key, { metatype }]) =>
-          metatype && metatype.name === InternalCoreModule.name,
-      )
-      .map(([key, value]) => value);
+    if (this.coreModuleRef === undefined) {
+      const coreModuleArray = [...this.modulesContainer.entries()]
+        .filter(
+          ([key, { metatype }]) =>
+            metatype && metatype.name === InternalCoreModule.name,
+        )
+        .map(([key, value]) => value);
+
+      this.coreModuleRef = head(coreModuleArray) ?? null;
+    }
 
-    const coreModuleRef = head(coreModuleArray);
-    if (!coreModuleRef) {
+    if (!this.coreModuleRef) {
       return;
     }
-    const wrapper = coreModuleRef.getProviderByKey(REQUEST);
+
+    const wrapper = this.coreModuleRef.getProviderByKey(REQUEST);
     wrapper.setInstanceByContextId(contextId, {
       instance: contextId.getParent ? contextId.payload : request,
       isResolved: true,