feat: add isAddressInfo helper function

Author: jsjoeio

src/node/util.ts

@@ -485,6 +485,15 @@ export function isNodeJSErrnoException(error: unknown): error is NodeJS.ErrnoExc
   return error !== undefined && (error as NodeJS.ErrnoException).code !== undefined
 }
 
+/**
+ * A helper function which returns a boolean indicating whether
+ * the given address is AddressInfo and has .address
+ * and a .port property.
+ */
+export function isAddressInfo(address: unknown): address is net.AddressInfo {
+  return address !== null && typeof address !== "string" && (address as net.AddressInfo).port !== undefined
+}
+
 // TODO: Replace with proper templating system.
 export const escapeJSON = (value: cp.Serializable) => JSON.stringify(value).replace(/"/g, """)