Bug Report Title

[ybbus]

Ethers Version

5.7.2

Search Terms

estimateGas, reverted, UNPREDICTABLE_GAS_LIMIT

Describe the Problem

It is not possible to estimateGas when using a provider in an ethers.contract instead of a signer.

const provider= new ethers.providers.JsonRpcProvider('https://polygon-mumbai.g.alchemy.com/v2/XXXXXXX', 80001)
const ethersContract = new ethers.Contract("contracAddress", myABI, provider)
const gasEstimationEthers = await ethersContract.estimateGas.mint('0xc64b6c3231465c350a9604df8ffbcfeb20d8c910', 1, 1, 0x0)
console.log(`Ethers gas estimation: ${gasEstimationEthers}`)

The problem is, that the estimation call generates the following request:

{
  "method": "eth_estimateGas",
  "params": [
    {
      "to": "0xb2fa72d58174d..........................",
      "data": "0x........................................................"
    }
  ],
  "id": 43,
  "jsonrpc": "2.0"
}

The estimation fails and returns an error since it seems the estimation does not have access to msg.sender because it is missing in the request.
So every method call that makes use of msg.sender will not return an estimation since it fails. This results in an error like:

transaction may fail or may require manual gas limit [ See: https://links.ethers.org/v5-errors-UNPREDICTABLE_GAS_LIMIT ] (reason="execution reverted: 8", method="estimateGas", transaction={

The same call works if I execute it with postman and adding the from address like this:

{
  "method": "eth_estimateGas",
  "params": [
    {
      "to": "0xb2fa72d58174d..........................",
      "from": "0x123.....................",
      "data": "0x........................................................"
    }
  ],
  "id": 43,
  "jsonrpc": "2.0"
}

The problem is, that I cannot tell ethers, to use a specific from-address for estimation. I think I have to use a signer instead of a provider (?). Internally ethers checks if it has a signer or a provider, and if it is a provider, the from property is missing.
But since I do not have a private key (for estimation you do not need one anyway) this also does not seem to work.

I tried it with web3js library and here you have an option to provide a from address when calling an estimation:

const gasEstimationWeb3 = await web3Contract.methods.mint('0xc64b6c3.................', 1, 1, 0x0).estimateGas({ from: '0xc64b6c32......' })

This works as expected.

Is there something similar for ethers? Otherwise it is not possible to prepare a transaction for a private key you don't own if you need to estimate the gasLimit.

Code Snippet

No response

Contract ABI

No response

Errors

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: 8", method="estimateGas", transaction={".........

Environment

Altcoin - Please specify (e.g. Polygon)

Environment (Other)

Polygon Mumbai

[ricmoo]

If you use a VoidSigner, you can call a contract from a specific account, for example contract.connect(fromAddress).estimateGas.mint(...). When using .connectwith a string address, it will automatically create aVoidSigner` for you.

You can also specify from in the overrides: contract.estiamteGas.mint(... , { from: fromAddress }).

Let me know if that helps. :)

[ybbus]

This is exactly what I was looking for. Thank you! Did I miss that in the documentation?