Make `node-fetch` polyfill better (#2962)

* Make `node-fetch` polyfill better

* fixup

* Test using localhost

* Add comment

---------

Co-authored-by: Jarred Sumner <709451+Jarred-Sumner@users.noreply.github.com>

2 files changed, 109 insertions, 4 deletions

diff --git a/src/node-fallbacks/node-fetch.js b/src/node-fallbacks/node-fetch.js
index 4e5e96bdd..f124e6461 100644
--- a/src/node-fallbacks/node-fetch.js
+++ b/src/node-fallbacks/node-fetch.js
@@ -1,8 +1,92 @@
-var fetchHandler = globalThis.fetch;
+var { Headers, Request, Response, Blob, File = Blob, FormData, fetch: realFetch } = globalThis;
 
 if ("Bun" in globalThis) {
-  fetchHandler = Bun.fetch;
+  realFetch = Bun.fetch;
 }
 
-export default fetchHandler;
-export { fetchHandler as fetch };
+function fetch(...args) {
+  // require("node-fetch") returns the default export which means we need to
+  // repeat the ESM exports onto it.
+  //
+  // We don't want to copy that onto the global fetch object, so we wrap it.
+  return realFetch(...args);
+}
+
+class AbortError extends DOMException {
+  constructor(message) {
+    super(message, "AbortError");
+  }
+}
+
+class FetchBaseError extends Error {
+  constructor(message, type) {
+    super(message);
+    this.type = type;
+  }
+}
+
+class FetchError extends FetchBaseError {
+  constructor(message, type, systemError) {
+    super(message, type);
+    this.code = systemError?.code;
+  }
+}
+
+function blobFrom(path, options) {
+  if ("Bun" in globalThis) {
+    return Promise.resolve(Bun.file(data));
+  }
+
+  return fetch(path, options).then(response => response.blob());
+}
+
+function blobFromSync(path, options) {
+  if ("Bun" in globalThis) {
+    return Bun.file(data);
+  }
+
+  return fetch(path, options).then(response => response.blob());
+}
+
+var fileFrom = blobFrom;
+var fileFromSync = blobFromSync;
+
+function isRedirect(code) {
+  return code === 301 || code === 302 || code === 303 || code === 307 || code === 308;
+}
+
+export default Object.assign(fetch, {
+  AbortError,
+  Blob,
+  FetchBaseError,
+  FetchError,
+  File,
+  FormData,
+  Headers,
+  Request,
+  Response,
+  blobFrom,
+  blobFromSync,
+  fileFrom,
+  fileFromSync,
+  isRedirect,
+  [Symbol.for("CommonJS")]: 0,
+});
+
+export {
+  AbortError,
+  Blob,
+  FetchBaseError,
+  FetchError,
+  File,
+  FormData,
+  Headers,
+  Request,
+  Response,
+  blobFrom,
+  blobFromSync,
+  fileFrom,
+  fileFromSync,
+  isRedirect,
+  fetch,
+};
diff --git a/test/js/node/fs/node-fetch.test.js b/test/js/node/fs/node-fetch.test.js
new file mode 100644
index 000000000..11c5e0ed3
--- /dev/null
+++ b/test/js/node/fs/node-fetch.test.js
@@ -0,0 +1,21 @@
+import { fetch, Response, Request, Headers } from "node-fetch";
+
+import { test, expect } from "bun:test";
+
+test("node-fetch", () => {
+  expect(Response).toBe(globalThis.Response);
+  expect(Request).toBe(globalThis.Request);
+  expect(Headers).toBe(globalThis.Headers);
+});
+
+test("node-fetch fetches", async () => {
+  const server = Bun.serve({
+    port: 0,
+    fetch(req, server) {
+      server.stop();
+      return new Response();
+    },
+  });
+  expect(await fetch("http://" + server.hostname + ":" + server.port)).toBeInstanceOf(Response);
+  server.stop(true);
+});