enhance(node-fetch): use undici when available

Author: ardatan

.changeset/serious-houses-flow.md

@@ -0,0 +1,5 @@
+---
+'@whatwg-node/node-fetch': patch
+---
+
+Use `undici` when available over `node:http`

jest.config.js

@@ -15,10 +15,12 @@ try {
   console.warn(`Failed to load uWebSockets.js. Skipping tests that require it.`, err);
 }
 
-try {
-  globals.libcurl = require('node-libcurl');
-} catch (err) {
-  console.warn('Failed to load node-libcurl. Skipping tests that require it.', err);
+if (process.env.LEAK_TEST) {
+  try {
+    globals.TEST_LIBCURL = require('node-libcurl');
+  } catch (err) {
+    console.warn('Failed to load node-libcurl. Skipping tests that require it.', err);
+  }
 }
 
 module.exports = {

package.json

@@ -21,7 +21,7 @@
     "prettier": "prettier --ignore-path .gitignore --ignore-path .prettierignore --write --list-different .",
     "prettier:check": "prettier --ignore-path .gitignore --ignore-path .prettierignore --check .",
     "release": "changeset publish",
-    "test": "jest --runInBand --forceExit",
+    "test": "jest --forceExit",
     "test:bun": "bun test --bail",
     "test:deno": "deno test ./packages/**/*.spec.ts --allow-all --fail-fast --no-check --unstable-sloppy-imports --trace-leaks",
     "test:leaks": "LEAK_TEST=1 jest --detectOpenHandles --detectLeaks --runInBand --forceExit",

packages/fetch/dist/node-ponyfill.js

@@ -1,15 +1,7 @@
 
 const createNodePonyfill = require('./create-node-ponyfill');
-const shouldSkipPonyfill = require('./shouldSkipPonyfill');
 const ponyfills = createNodePonyfill();
 
-if (!shouldSkipPonyfill()) {
-  try {
-    const nodelibcurlName = 'node-libcurl'
-    globalThis.libcurl = globalThis.libcurl || require(nodelibcurlName);
-  } catch (e) { }
-}
-
 module.exports.fetch = ponyfills.fetch;
 module.exports.Headers = ponyfills.Headers;
 module.exports.Request = ponyfills.Request;

packages/node-fetch/package.json

@@ -41,7 +41,8 @@
   "devDependencies": {
     "@types/busboy": "1.5.4",
     "@types/pem": "^1.14.0",
-    "pem": "^1.14.8"
+    "pem": "^1.14.8",
+    "undici": "^7.3.0"
   },
   "publishConfig": {
     "directory": "dist",

packages/node-fetch/src/Request.ts

@@ -137,6 +137,8 @@ export class PonyfillRequest<TJSON = any> extends PonyfillBody<TJSON> implements
 
   agent: HTTPAgent | HTTPSAgent | false | undefined;
 
+  dispatcher: import('undici').Dispatcher | undefined;
+
   private _signal: AbortSignal | undefined | null;
 
   get signal() {

packages/node-fetch/src/declarations.d.ts

@@ -32,7 +32,7 @@ declare module '@kamilkisiela/fast-url-parser' {
 }
 
 // TODO
-declare var libcurl: any;
+declare var TEST_LIBCURL: any;
 declare module 'scheduler/tracing' {
   export type Interaction = any;
 }

packages/node-fetch/src/fetch.ts

@@ -1,8 +1,10 @@
 import { Buffer } from 'node:buffer';
 import { createReadStream } from 'node:fs';
 import { fileURLToPath } from 'node:url';
-import { fetchCurl } from './fetchCurl.js';
+import { isPromise } from 'node:util/types';
+import { createFetchCurl } from './fetchCurl.js';
 import { fetchNodeHttp } from './fetchNodeHttp.js';
+import { createFetchUndici } from './fetchUndici.js';
 import { PonyfillRequest, RequestPonyfillInit } from './Request.js';
 import { PonyfillResponse } from './Response.js';
 import { PonyfillURL } from './URL.js';
@@ -57,15 +59,28 @@ function isURL(obj: any): obj is URL {
   return obj != null && obj.href != null;
 }
 
-export function fetchPonyfill<TResponseJSON = any, TRequestJSON = any>(
-  info: string | PonyfillRequest<TRequestJSON> | URL,
-  init?: RequestPonyfillInit,
-): Promise<PonyfillResponse<TResponseJSON>> {
-  if (typeof info === 'string' || isURL(info)) {
-    const ponyfillRequest = new PonyfillRequest(info, init);
-    return fetchPonyfill(ponyfillRequest);
-  }
-  const fetchRequest = info;
+let fetchFn$: Promise<typeof fetchNodeHttp>;
+let fetchFn: typeof fetchNodeHttp;
+
+function getNativeGlobalDispatcher(): import('undici').Dispatcher {
+  // @ts-expect-error - We know it is there
+  return globalThis[Symbol.for('undici.globalDispatcher.1')];
+}
+
+function createFetchFn() {
+  const libcurlModuleName = 'node-libcurl';
+  const undiciModuleName = 'undici';
+  return import(libcurlModuleName).then(
+    libcurl => createFetchCurl(libcurl),
+    () =>
+      import(undiciModuleName).then(
+        (undici: typeof import('undici')) => createFetchUndici(() => undici.getGlobalDispatcher()),
+        () => createFetchUndici(getNativeGlobalDispatcher),
+      ),
+  );
+}
+
+function fetchNonHttp(fetchRequest: PonyfillRequest) {
   if (fetchRequest.url.startsWith('data:')) {
     const response = getResponseForDataUri(fetchRequest.url);
     return fakePromise(response);
@@ -79,8 +94,54 @@ export function fetchPonyfill<TResponseJSON = any, TRequestJSON = any>(
     const response = getResponseForBlob(fetchRequest.url);
     return fakePromise(response);
   }
-  if (globalThis.libcurl && !fetchRequest.agent) {
-    return fetchCurl(fetchRequest);
+}
+
+function normalizeInfo(info: string | PonyfillRequest | URL, init?: RequestPonyfillInit) {
+  if (typeof info === 'string' || isURL(info)) {
+    return new PonyfillRequest(info, init);
   }
-  return fetchNodeHttp(fetchRequest);
+  return info;
+}
+
+export function createFetchPonyfill(fetchFn: typeof fetchNodeHttp) {
+  return function fetchPonyfill<TResponseJSON = any, TRequestJSON = any>(
+    info: string | PonyfillRequest<TRequestJSON> | URL,
+    init?: RequestPonyfillInit,
+  ): Promise<PonyfillResponse<TResponseJSON>> {
+    info = normalizeInfo(info, init);
+
+    const nonHttpRes = fetchNonHttp(info);
+
+    if (nonHttpRes) {
+      return nonHttpRes;
+    }
+
+    return fetchFn(info);
+  };
+}
+
+export function fetchPonyfill<TResponseJSON = any, TRequestJSON = any>(
+  info: string | PonyfillRequest<TRequestJSON> | URL,
+  init?: RequestPonyfillInit,
+): Promise<PonyfillResponse<TResponseJSON>> {
+  info = normalizeInfo(info, init);
+
+  const nonHttpRes = fetchNonHttp(info);
+
+  if (nonHttpRes) {
+    return nonHttpRes;
+  }
+
+  if (!fetchFn) {
+    fetchFn$ ||= createFetchFn();
+    if (isPromise(fetchFn$)) {
+      return fetchFn$.then(newFetchFn => {
+        fetchFn = newFetchFn;
+        return fetchFn(info);
+      });
+    }
+    fetchFn = fetchFn$;
+  }
+
+  return fetchFn(info);
 }