How to listen to events to sort off-chain - deployment

Question

I read this article on sorting an array off-chain using event listeners, but my array doesn't appear to be sorted in time when the array is called in typescript.
This is my contract:
pragma solidity 0.8.4;
pragma experimental ABIEncoderV2;
contract Test {
uint256[] unsortedArr;
uint256[] sortedArr;
event sort(uint256[]);
function addElement(uint256 element) public {
unsortedArr.push(element);
}
function sortOffChain() public returns (uint[] memory)
{
/*On the backend, the algorithm would look something like this -
*event listener listening for sort()
*calls sort function in typescript upon getting triggered
*calls getSortedData() function with returned value of sort()
*/
emit sort(unsortedArr);
// I want sortedArr below to be sorted by the time the return is called
return sortedArr;
}
function getSortedData(uint256[] memory sortedData) public
{
sortedArr = sortedData;
}
// for typescript test
function getUnsortedArr() public view returns (uint256[] memory) {
return unsortedArr;
}
function getSortedArr() public view returns (uint256[] memory) {
return sortedArr;
}
}
This is what the event listener looks like in TypeScript:
async function main() {
;
// deploying
const Test = await hre.ethers.getContractFactory("Test");
const test = await Test.deploy();
await test.deployed();
console.log("Test deployed to", test.address);
// add elements to array
await test.addElement(5);
await test.addElement(3);
await test.addElement(7);
await test.addElement(2);
await test.addElement(1);
await test.addElement(9);
// event listener
const OffChainResult = await test.sortOffChain();
test.on("sort", (arr: []) => {
let arrayForSort = [...arr];
const sortedArr = arrayForSort.sort((n1: number,n2 : number) => n1 - n2);
console.log("array sorted");
test.getSortedData(sortedArr);
console.log("getSortedData completed");
}
);
console.log("output of getSortedData:");
console.log(OffChainResult);
This is what comes out in the terminal when I run the script:
Test deployed to 0x5FbDB2315678afecb367f032d93F642f64180aa3
output of getSortedData:
{
hash: '0x40eeca2775e29300e51f3a067c99195f0cf33ee0aac73eaeaf05d826b41c3d4c',
type: 2,
accessList: [],
blockHash: '0xd952eb1b086de3b1ee213fff01b464925670bc6d7e515ac3f7dad3b732471857',
blockNumber: 8,
transactionIndex: 0,
confirmations: 1,
from: '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
gasPrice: BigNumber { value: "1346048670" },
maxPriorityFeePerGas: BigNumber { value: "1000000000" },
maxFeePerGas: BigNumber { value: "1692097340" },
gasLimit: BigNumber { value: "29021272" },
to: '0x5FbDB2315678afecb367f032d93F642f64180aa3',
value: BigNumber { value: "0" },
nonce: 7,
data: '0xb8dbac2c',
r: '0x621282eec4ac159b052250faa62aa5e954510ba91e841d3477bf0228ecf952d9',
s: '0x7d36e86d604b58006dd918efc52babd3f3e61dd9f80e36fa2e3e8a9a03fe5298',
v: 1,
creates: null,
chainId: 31337,
wait: [Function (anonymous)]
}
array sorted
getSortedData completed
There are two issues: (1) getSortedData() which is called by sortOffChain() returns a value before the event listener gets a chance to sort the array and set sortedArr to the right value and (2) even if the array isn't sorted, sortOffChain() should return an empty array, not whatever the console output for `OffChain.
Is this just an issue with how I made the event listener? Do I need to put the lines of code in a different order? Also, what is the thing that the console output for OffChainResult.
I've also heard that the sorted array that is to be given to the smart contract can't be validated. How do I ensure that it is?