Return hbar fee / gas used on failed smart contract execution

[iron4548]

Description

I use ContractExecuteTransaction and on a successful call, I can get the hbar fee / gas used value via contractExecuteRec.transactionFee. However, if the smart contract call failed due to a revert or due to a require, it will throw an error (unsure if this is by design or not). Within the error there are a bunch of records but none of them contains the hbar fee / gas used value. The failed transaction can be queried via mirror node to get the fee. The question is - is it possible to get the hbar fee / gas used value on a failed/reverted smart contract call so that I don't need to query the mirror node for it?

const contractExecuteTx = new ContractExecuteTransaction()
.setContractId(contractId)
.setGas(gasLim)
.setTransactionMemo(memo)
.setFunction(functionName, params)
.freezeWith(client);

try {      

    const signedTx = await contractExecuteTx.sign(privateKey);
    const contractExecuteSubmit = await signedTx.execute(client);
    const contractExecuteRec = await contractExecuteSubmit.getRecord(client);

    console.log(`txFee: ${contractExecuteRec.transactionFee}`);

} catch (err:any) {
    console.log(`txFee: ?`);
}

Steps to reproduce

Use @hashgraph/sdk 2.24.2

1. Create a ContractExecuteTransaction
2. Call a smart contract and cause a require or a revert to occur
3. An 'Status error' exception occurs
4. Now try and figure out how to get the hbar fee / gas used for the failed smart contract call.

Additional context

No response

Hedera network

mainnet

Version

2.24.2

Operating system

None

[iron4548]

Here's the dump of the error object on smart contract call revert/require trigger

status: Status { _code: 33 },
  transactionId: TransactionId {
    accountId: AccountId {
      shard: [Long],
      realm: [Long],
      num: [Long],
      aliasKey: null,
      evmAddress: null,
      _checksum: null
    },
    validStart: Timestamp { seconds: [Long], nanos: [Long] },
    scheduled: false,
    nonce: null
  },
  transactionReceipt: TransactionReceipt {
    status: Status { _code: 33 },
    accountId: null,
    fileId: null,
    contractId: ContractId {
      shard: [Long],
      realm: [Long],
      num: [Long],
      evmAddress: null,
      _checksum: null
    },
    topicId: null,
    tokenId: null,
    scheduleId: null,
    exchangeRate: ExchangeRate {
      hbars: 30000,
      cents: 150926,
      expirationTime: 2023-05-25T04:00:00.000Z,
      exchangeRateInCents: 5.030866666666666
    },
    topicSequenceNumber: Long { low: 0, high: 0, unsigned: false },
    topicRunningHash: Uint8Array(0) [],
    totalSupply: Long { low: 0, high: 0, unsigned: false },
    scheduledTransactionId: null,
    serials: [],
    duplicates: [],
    children: []
  }
}

[ochikov]

Hello @iron4548, and thank you for the issue.

• On the first question about the require: There are three main solidity error functions: assert, require, and revert. Using require unused gas is returned to the caller and the state is reversed to the original state, so it's by design to throw.
• On the second question about the transactionFee: Currently, there is no way of returning it. You need to get it through the mirror node. I've requested the core team if it's possible to be added and they will consider it, but for now, it can be retrieved by the mirror node.
• We are detecting the status code and if the status code is not OK (status 22) we are returning the exception error with the transaction id and status code.

[ochikov]

@iron4548 I will close the issue?

[iron4548]

@ochikov yes you may.

"I've requested the core team if it's possible to be added and they will consider it" - can this be tracked elsewhere?

[ochikov]

Hello @iron4548, I've researched more deeply the issue and there is a way to get it through the SDK because the consensus node is returning that information. We are going to provide such kind of functionality with the new version. I will tag you here when we are ready.