node-fetch: name FetchError and AbortError like node-fetch

src/js/thirdparty/node-fetch.ts

@@ -197,25 +197,44 @@ async function fetch(
   return response;
 }
 
-class AbortError extends DOMException {
-  constructor(message) {
-    super(message, "AbortError");
-  }
-}
-
+// node-fetch names each error after its class and keeps the system error's code and syscall:
+// https://github.com/node-fetch/node-fetch/blob/8b3320d2a7c07bce4afc6b2bf6c3bbddda85b01f/src/errors/base.js
+// https://github.com/node-fetch/node-fetch/blob/8b3320d2a7c07bce4afc6b2bf6c3bbddda85b01f/src/errors/fetch-error.js
 class FetchBaseError extends Error {
   type: string;
 
   constructor(message, type) {
     super(message);
     this.type = type;
   }
+
+  get name() {
+    return this.constructor.name;
+  }
+
+  get [Symbol.toStringTag]() {
+    return this.constructor.name;
+  }
 }
 
 class FetchError extends FetchBaseError {
+  declare code?: string;
+  declare errno?: string;
+  declare erroredSysCall?: string;
+
   constructor(message, type, systemError) {
     super(message, type);
-    this.code = systemError?.code;
+    if (systemError) {
+      this.code = this.errno = systemError.code;
+      this.erroredSysCall = systemError.syscall;
+    }
+  }
+}
+
+// https://github.com/node-fetch/node-fetch/blob/8b3320d2a7c07bce4afc6b2bf6c3bbddda85b01f/src/errors/abort-error.js
+class AbortError extends FetchBaseError {
+  constructor(message, type = "aborted") {
+    super(message, type);
   }
 }
 

test/js/node/http/node-fetch.test.js

@@ -1,6 +1,6 @@
 import * as vercelFetch from "@vercel/fetch";
 import * as iso from "isomorphic-fetch";
-import fetch2, { fetch, Headers, Request, Response } from "node-fetch";
+import fetch2, { AbortError, fetch, FetchError, Headers, Request, Response } from "node-fetch";
 import { once } from "node:events";
 import http from "node:http";
 import * as stream from "stream";
@@ -417,6 +417,30 @@ test("node-fetch json() resolves null for a body that is the JSON text null", as
   expect(await (await fetch2(server.url)).json()).toBeNull();
 });
 
+test("node-fetch FetchError and AbortError match node-fetch's error classes", () => {
+  const error = new FetchError("request to http://example.test/ failed", "system", {
+    code: "ECONNRESET",
+    syscall: "read",
+  });
+  expect(error).toBeInstanceOf(Error);
+  expect(error.name).toBe("FetchError");
+  expect(String(error)).toBe("FetchError: request to http://example.test/ failed");
+  expect(Object.prototype.toString.call(error)).toBe("[object FetchError]");
+  expect(error.type).toBe("system");
+  expect(error.code).toBe("ECONNRESET");
+  expect(error.errno).toBe("ECONNRESET");
+  expect(error.erroredSysCall).toBe("read");
+
+  const plain = new FetchError("invalid json", "invalid-json");
+  expect(plain.name).toBe("FetchError");
+  expect("code" in plain).toBe(false);
+
+  const aborted = new AbortError("The operation was aborted.");
+  expect(aborted).toBeInstanceOf(Error);
+  expect(aborted.name).toBe("AbortError");
+  expect(aborted.type).toBe("aborted");
+});
+
 test("node-fetch request body streams properly", async () => {
   let responseResolve;
   const responsePromise = new Promise(resolve => {