How to get reverted error name with ethers in javascript?

Question

I write a solidty code and also a custom error like this:

error TestObject__IndexNotFound();

function getProductChain(uint256 index) public view returns(SupplyChain memory){
    if (index > (counter - 1) || index < 0){
        revert TestObject__IndexNotFound();
    }
    SupplyChain memory spChain = supplyChain[index];
    return spChain;
}

But when i catch this error, the name of this error doesn't show:

 try{
     const transactionResponse = await contract.getProductChain(index);
     console.log(transactionResponse);
 }catch(error){
     console.log(error);
 }

Instead, it just writes 'revert' with no reason!. I can write require with string but I want to use error and revert. Last time when I used ethers and hardhat (node), the reverted error was shown in my console. But now it doesn't. I used ethers and ganache this time:

Error: missing revert data in call exception; Transaction reverted without a reason 
string....

Answer 1

In ethers v6, you can use error.data that can be decoded from the contract to get the reverted error.

} catch (e) {
    if (e.data && contract) {
      const decodedError = contract.interface.parseError(e.data);
      console.log(`Transaction failed: ${decodedError?.name}`);
    } else {
      console.log(`Error in widthrawContract:`, e);
    }
  }

---

Detailled Example

Solidity

  modifier onlyOwner() {
        if (msg.sender != i_owner) revert FundMe__NotOwner();
        _;
    }

Browser code

export const widthrawContract = async () => {
  if (!isCryptoWalletAvailable()) return;
  let provider, signer, contract;
  try {
    console.log(`Widthrawing wallet...`);
    provider = new ethers.BrowserProvider(window.ethereum);
    signer = await provider.getSigner();
    contract = new ethers.Contract(FUND_ME_CONTRACT_ADDR, FUND_ME_ABI, signer);

    await contract.withdraw({});
  } catch (e) {
    if (e.data && contract) {
      const decodedError = contract.interface.parseError(e.data);
      console.log(`Transaction failed: ${decodedError?.name}`);
    } else {
      console.log(`Error in widthrawContract:`, e);
    }
  }
};

Error received from the browser:

Transaction failed: FundMe__NotOwner

In ethers V5, it's tiny different