Lazy load node:net for improved edge runtime compatibility

README.md

@@ -53,6 +53,20 @@ toRegistrableDomain("192.168.0.1");                      // => null
 - `isRegistered(domain, options?) => Promise<boolean>`
 - `isAvailable(domain, options?) => Promise<boolean>`
 
+### Edge runtimes (e.g., Vercel Edge)
+
+WHOIS requires a raw TCP connection over port 43 via `node:net`, which is not available on edge runtimes. This package lazily loads `node:net` only when the WHOIS code path runs. To use rdapper safely on edge:
+
+- Prefer RDAP only:
+
+```ts
+import { lookupDomain } from "rdapper";
+
+const res = await lookupDomain("example.com", { rdapOnly: true });
+```
+
+- If `rdapOnly` is omitted and the code path reaches WHOIS on edge, rdapper throws a clear runtime error indicating WHOIS is unsupported on edge and to run in Node or set `rdapOnly: true`.
+
 ### Options
 
 - `timeoutMs?: number` – Total timeout budget per network operation (default `15000`).

package-lock.json

@@ -13,7 +13,7 @@
       },
       "devDependencies": {
         "@biomejs/biome": "2.2.5",
-        "@types/node": "24.7.1",
+        "@types/node": "24.7.2",
         "tsdown": "0.15.6",
         "typescript": "5.9.3",
         "vitest": "^3.2.4"
@@ -1392,9 +1392,9 @@
       "license": "MIT"
     },
     "node_modules/@types/node": {
-      "version": "24.7.1",
-      "resolved": "https://registry.npmjs.org/@types/node/-/node-24.7.1.tgz",
-      "integrity": "sha512-CmyhGZanP88uuC5GpWU9q+fI61j2SkhO3UGMUdfYRE6Bcy0ccyzn1Rqj9YAB/ZY4kOXmNf0ocah5GtphmLMP6Q==",
+      "version": "24.7.2",
+      "resolved": "https://registry.npmjs.org/@types/node/-/node-24.7.2.tgz",
+      "integrity": "sha512-/NbVmcGTP+lj5oa4yiYxxeBjRivKQ5Ns1eSZeB99ExsEQ6rX5XYU1Zy/gGxY/ilqtD4Etx9mKyrPxZRetiahhA==",
       "dev": true,
       "license": "MIT",
       "dependencies": {

package.json

@@ -43,7 +43,7 @@
   },
   "devDependencies": {
     "@biomejs/biome": "2.2.5",
-    "@types/node": "24.7.1",
+    "@types/node": "24.7.2",
     "tsdown": "0.15.6",
     "typescript": "5.9.3",
     "vitest": "^3.2.4"

src/whois/client.test.ts

@@ -0,0 +1,15 @@
+// src/whois/edge-mock.test.ts
+import { describe, expect, it, vi } from "vitest";
+
+vi.mock("net", () => {
+  throw new Error("node:net unavailable (edge)");
+});
+
+describe("edge runtime behavior", () => {
+  it("throws a clear error when WHOIS hits node:net on edge", async () => {
+    const { whoisQuery } = await import("../whois/client");
+    await expect(whoisQuery("whois.iana.org", "com")).rejects.toThrow(
+      /WHOIS client is only available in Node.js runtimes/,
+    );
+  });
+});

src/whois/client.ts

@@ -1,4 +1,3 @@
-import { createConnection } from "node:net";
 import { withTimeout } from "../lib/async";
 import { DEFAULT_TIMEOUT_MS } from "../lib/constants";
 import type { LookupOptions } from "../types";
@@ -29,14 +28,28 @@ export async function whoisQuery(
 }
 
 // Low-level WHOIS TCP client. Some registries require CRLF after the domain query.
-function queryTcp(
+async function queryTcp(
   host: string,
   port: number,
   query: string,
   options?: LookupOptions,
 ): Promise<string> {
+  let net: typeof import("net") | null;
+  try {
+    // biome-ignore lint/style/useNodejsImportProtocol: compatibility
+    net = await import("net");
+  } catch {
+    net = null;
+  }
+
+  if (!net?.createConnection) {
+    throw new Error(
+      "WHOIS client is only available in Node.js runtimes; try setting `rdapOnly: true`.",
+    );
+  }
+
   return new Promise((resolve, reject) => {
-    const socket = createConnection({ host, port });
+    const socket = net.createConnection({ host, port });
     let data = "";
     let done = false;
     const cleanup = () => {

tsconfig.json

@@ -13,7 +13,8 @@
     "esModuleInterop": true,
     "isolatedModules": true,
     "verbatimModuleSyntax": true,
-    "skipLibCheck": true
+    "skipLibCheck": true,
+    "types": ["vitest/globals"]
   },
   "include": ["src/**/*"],
   "exclude": ["node_modules", "dist"]

vitest.config.ts

@@ -6,7 +6,7 @@ export default defineConfig({
     include: ["src/**/*.test.ts"],
     exclude: ["dist/**", "node_modules/**"],
     sequence: { hooks: "list" },
-    globals: false,
+    globals: true,
     testTimeout: process.env.SMOKE === "1" ? 30000 : 5000,
   },
 });