How to call contract function with ethersJs?

Question

I wanna call my smart contract function using ethersjs , but when i call function i got this error:

Unhandled Runtime Error Error: cannot estimate gas; transaction may fail or may require manual gas limit [ See: https://links.ethers.org/v5-errors-UNPREDICTABLE_GAS_LIMIT ] (reason="execution reverted", method="estimateGas", transaction={"from":"0x1204D7F27702d793260Ad5a406dDEE7660d21B61","to":"0xf3BfC4Ce2c8392fc93D24e74193b1d133320126e","data":"0x15364cd50000000000000000000000001204d7f27702d793260ad5a406ddee7660d21b61","accessList":null}, error={"code":-32000,"message":"execution reverted"}, code=UNPREDICTABLE_GAS_LIMIT, version=providers/5.7.2)

and here is my function codes:

const _faucetContract = new ethers.Contract(faucetContractAddress , faucetAbi , signer )

const getFaucetToken = async () => {
    await _faucetContract.getFaucet(signerAddress)
  }

and that's my function in .sol contract:

    function getFaucet(address user) external {
        require(msg.sender == user, 'you can not sent token for another address');
        require(msg.sender != address(0),"address zero");
        require(timeLastFaucet[msg.sender] + 1 days < block.timestamp,"once a day");

        _mint(user, 50000000000000000000);
        timeLastFaucet[msg.sender] = block.timestamp ;

    }

i think i should set gas fee and gas limit for my function but i don't know how??

can anyone explain how i can define arguments and details that we need to call contract functions?

Thanks a lot.

Answer 1

Function calls in ethers.js accept an extra 'overrides' parameter’s than can be used to set gas and gas price.

For example to set the gasLimit to 100k

const getFaucetToken = async () => {
  await _faucetContract.getFaucet(signerAddress, { gasLimit: 100000, })
}

Check the documentation for other fields https://docs.ethers.org/v5/api/contract/contract/#Contract-functionsCall.

Answer 2

const gasLimit = 21000; // The gas limit for the transaction
const gasPrice = ethers.utils.parseUnits("20.0", "gwei"); // The gas price, in gwei

You should be able to set the gas limit/price using the above.