use slice

karma.conf.cjs

@@ -5,9 +5,7 @@ const path = require("path");
 const ResolveTypeScriptPlugin = require("resolve-typescript-plugin");
 
 const output = {
-  path:
-    path.join(os.tmpdir(), "_karma_webpack_") +
-    Math.floor(Math.random() * 1000000),
+  path: path.resolve(__dirname),
 };
 
 module.exports = function (config) {

src/rln.ts

@@ -32,7 +32,7 @@ function concatenate(...input: Uint8Array[]): Uint8Array {
  * @returns BigInt
  */
 function buildBigIntFromUint8Array(array: Uint8Array): bigint {
-  const bigEndianArray = array.reverse();
+  const bigEndianArray = array.slice().reverse();
   // hack for Uint8Array.map that has Uint8Array -> Uint8Array definition that prevents from mapping to other types
   const hexString = (bigEndianArray as unknown as number[])
     .map((b) => b.toString(16).padStart(2, "0"))