transfer function does not working correctly on ERC20 presale smart contract while testing using Chai and Hardhat

I have written ERC20 token presale smart contract. I have defined token transfer function as follows:

function transferTokensToPresale(uint256 presaleSupplyAmount_) public onlyOwner returns (bool) {
        require(presaleSupplyAmount_ > 0, "Amount must be greater than zero");
        require(
            token.balanceOf(msg.sender) >= presaleSupplyAmount_,
            "Insufficient balance"
        );
        require(block.timestamp < startTime, "Presale has already started");

        //Send the tokens to the presale contract
        SafeERC20.safeTransferFrom(
            token,
            msg.sender,
            address(this),
            presaleSupplyAmount_
        );
        return true;
    }

But while I was testing the function with Hardhat and Chai, the transfer didn't occur. There was no transaction fails or errors.

The test script I wrote was as follows:

console.log("token amount before transferring token to presale contract--->", presale.tokensAvailable());
const tx = await presale.connect(owner).transferTokensToPresale(presaleSupply);
console.log("token amount before transferring token to presale contract--->", presale.tokensAvailable());

The token amount in presale contract before and after transaction are the same.

What is the reason?

The transferTokensToPresale function works correctly. The error occurs in your test script. You need to add await tx.wait();

The correct codebase is like this:

console.log("token amount before transferring token to presale contract--->", presale.tokensAvailable());
const tx = await presale.connect(owner).transferTokensToPresale(presaleSupply);
await tx.wait();
console.log("token amount before transferring token to presale contract--->", presale.tokensAvailable());

This will fix your errors.