*Add helper functions for handling resolver responses

src/util.ts

@@ -1,3 +1,5 @@
+import { DNSRecord, DNSResult } from "./types.js";
+
 export function getTld(domain: string): string {
   if (domain.includes(".")) {
     domain = domain.split(".")[domain.split(".").length - 1];
@@ -28,3 +30,24 @@ export function isDomain(domain: string) {
     domain
   );
 }
+export function resolverEmptyResponse(): DNSResult {
+  return {
+    records: [],
+  };
+}
+
+export function resolverError(e: Error | string): DNSResult {
+  if (!(e instanceof Error)) {
+    e = new Error(e);
+  }
+  return {
+    records: [],
+    error: e,
+  };
+}
+
+export function resolveSuccess(records: DNSRecord[]): DNSResult {
+  return {
+    records,
+  };
+}