Facilitate the use of a polyfill for `BigInt`

By preferring the use of `BigInt` over integer literal (`n` postfix).

CHANGELOG.md

@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+### Changed
+
+- Prefer the use of `BigInt` over integer literal (`n` postfix) to facilitate the use of a polyfill.
+
 ### Fixed
 
 - Declare `it-pipe` dependency, import as per `it-pipe@2.0.0` convention.

src/lib/enr/enr.spec.ts

@@ -180,7 +180,7 @@ describe("ENR", function () {
     let record: ENR;
 
     beforeEach(() => {
-      const seq = 1n;
+      const seq = BigInt(1);
       privateKey = hexToBytes(
         "b71c71a67e1177ad4e901695e1b4b9ee17ae16c6668d313eac2f96dbcda3f291"
       );

src/lib/enr/enr.ts

@@ -32,7 +32,7 @@ export class ENR extends Map<ENRKey, ENRValue> {
 
   constructor(
     kvs: Record<ENRKey, ENRValue> = {},
-    seq: SequenceNumber = 1n,
+    seq: SequenceNumber = BigInt(1),
     signature: Uint8Array | null = null
   ) {
     super(Object.entries(kvs));