fix: fix socket info in response (#555)

<!-- This is an auto-generated comment: release notes by coderabbit.ai
-->
## Summary by CodeRabbit

- **New Features**
- Introduced the `BaseAgent` class with enhanced asynchronous local
storage capabilities.
- Updated `HttpAgent` to extend `BaseAgent`, improving address
validation and error handling during dispatch operations.

- **Bug Fixes**
- Enhanced validation in the `dispatch` method of `HttpAgent` to ensure
hostname validity.

- **Tests**
- Added a new assertion in the fetch tests to verify the local address
of the response socket.

- **Chores**
- Removed the `fetchOpaqueInterceptor` function and associated imports
to streamline the codebase.
<!-- end of auto-generated comment: release notes by coderabbit.ai -->

src/BaseAgent.ts

@@ -0,0 +1,27 @@
+import {
+  Agent,
+  Dispatcher,
+} from 'undici';
+import { AsyncLocalStorage } from 'node:async_hooks';
+import { FetchOpaque } from './FetchOpaqueInterceptor.js';
+
+export interface BaseAgentOptions extends Agent.Options {
+  opaqueLocalStorage?: AsyncLocalStorage<FetchOpaque>;
+}
+
+export class BaseAgent extends Agent {
+  #opaqueLocalStorage?: AsyncLocalStorage<FetchOpaque>;
+
+  constructor(options: BaseAgentOptions) {
+    super(options);
+    this.#opaqueLocalStorage = options.opaqueLocalStorage;
+  }
+
+  dispatch(options: Agent.DispatchOptions, handler: Dispatcher.DispatchHandler): boolean {
+    const opaque = this.#opaqueLocalStorage?.getStore();
+    if (opaque) {
+      (handler as any).opaque = opaque;
+    }
+    return super.dispatch(options, handler);
+  }
+}

src/FetchOpaqueInterceptor.ts

@@ -1,7 +1,6 @@
 // const { AsyncLocalStorage } = require('node:async_hooks');
 import { AsyncLocalStorage } from 'node:async_hooks';
 import symbols from './symbols.js';
-import { Dispatcher } from 'undici';
 
 // const RedirectHandler = require('../handler/redirect-handler')
 
@@ -28,14 +27,3 @@ export interface FetchOpaque {
 export interface OpaqueInterceptorOptions {
   opaqueLocalStorage: AsyncLocalStorage<FetchOpaque>;
 }
-
-export function fetchOpaqueInterceptor(opts: OpaqueInterceptorOptions) {
-  const opaqueLocalStorage = opts?.opaqueLocalStorage;
-  return (dispatch: Dispatcher['dispatch']): Dispatcher['dispatch'] => {
-    return function redirectInterceptor(opts: Dispatcher.DispatchOptions, handler: Dispatcher.DispatchHandler) {
-      const opaque = opaqueLocalStorage?.getStore();
-      (handler as any).opaque = opaque;
-      return dispatch(opts, handler);
-    };
-  };
-}

src/HttpAgent.ts

@@ -5,10 +5,11 @@ import {
   Dispatcher,
   buildConnector,
 } from 'undici';
+import { BaseAgent, BaseAgentOptions } from './BaseAgent.js';
 
 export type CheckAddressFunction = (ip: string, family: number | string, hostname: string) => boolean;
 
-export interface HttpAgentOptions extends Agent.Options {
+export interface HttpAgentOptions extends BaseAgentOptions {
   lookup?: LookupFunction;
   checkAddress?: CheckAddressFunction;
   connect?: buildConnector.BuildOptions,
@@ -31,7 +32,7 @@ class IllegalAddressError extends Error {
   }
 }
 
-export class HttpAgent extends Agent {
+export class HttpAgent extends BaseAgent {
   #checkAddress?: CheckAddressFunction;
 
   constructor(options: HttpAgentOptions) {

src/fetch.ts

@@ -8,6 +8,7 @@ import {
   Agent,
   getGlobalDispatcher,
   Pool,
+  Dispatcher,
 } from 'undici';
 // eslint-disable-next-line @typescript-eslint/ban-ts-comment
 // @ts-ignore
@@ -35,9 +36,10 @@ import {
   HttpMethod,
   RequestMeta,
 } from './Request.js';
-import { FetchOpaque, fetchOpaqueInterceptor } from './FetchOpaqueInterceptor.js';
+import { FetchOpaque } from './FetchOpaqueInterceptor.js';
 import { RawResponseWithMeta, SocketInfo } from './Response.js';
 import { IncomingHttpHeaders } from './IncomingHttpHeaders.js';
+import { BaseAgent, BaseAgentOptions } from './BaseAgent.js';
 
 export interface UrllibRequestInit extends RequestInit {
   // default is true
@@ -56,7 +58,7 @@ export type FetchResponseDiagnosticsMessage = {
 };
 
 export class FetchFactory {
-  static #dispatcher: Agent;
+  static #dispatcher: Dispatcher.ComposedDispatcher;
   static #opaqueLocalStorage = new AsyncLocalStorage<FetchOpaque>();
 
   static getDispatcher() {
@@ -68,17 +70,10 @@ export class FetchFactory {
   }
 
   static setClientOptions(clientOptions: ClientOptions) {
-    let dispatcherOption: Agent.Options = {
-      interceptors: {
-        Agent: [
-          fetchOpaqueInterceptor({
-            opaqueLocalStorage: FetchFactory.#opaqueLocalStorage,
-          }),
-        ],
-        Client: [],
-      },
+    let dispatcherOption: BaseAgentOptions = {
+      opaqueLocalStorage: FetchFactory.#opaqueLocalStorage,
     };
-    let dispatcherClazz: new (options: Agent.Options) => Agent = Agent;
+    let dispatcherClazz: new (options: BaseAgentOptions) => BaseAgent = BaseAgent;
     if (clientOptions?.lookup || clientOptions?.checkAddress) {
       dispatcherOption = {
         ...dispatcherOption,
@@ -87,21 +82,21 @@ export class FetchFactory {
         connect: clientOptions.connect,
         allowH2: clientOptions.allowH2,
       } as HttpAgentOptions;
-      dispatcherClazz = HttpAgent as unknown as new (options: Agent.Options) => Agent;
+      dispatcherClazz = HttpAgent as unknown as new (options: BaseAgentOptions) => BaseAgent;
     } else if (clientOptions?.connect) {
       dispatcherOption = {
         ...dispatcherOption,
         connect: clientOptions.connect,
         allowH2: clientOptions.allowH2,
       } as HttpAgentOptions;
-      dispatcherClazz = Agent;
+      dispatcherClazz = BaseAgent;
     } else if (clientOptions?.allowH2) {
       // Support HTTP2
       dispatcherOption = {
         ...dispatcherOption,
         allowH2: clientOptions.allowH2,
       } as HttpAgentOptions;
-      dispatcherClazz = Agent;
+      dispatcherClazz = BaseAgent;
     }
     FetchFactory.#dispatcher = new dispatcherClazz(dispatcherOption);
     initDiagnosticsChannel();

test/fetch.test.ts

@@ -46,6 +46,7 @@ describe('fetch.test.ts', () => {
     assert(requestDiagnosticsMessage!.request);
     assert(responseDiagnosticsMessage!.request);
     assert(responseDiagnosticsMessage!.response);
+    assert([ '127.0.0.1', '::1' ].includes(responseDiagnosticsMessage!.response.socket.localAddress));
 
     assert(fetchDiagnosticsMessage!.fetch);
     assert(fetchResponseDiagnosticsMessage!.fetch);