reason: 'Contract with a Signer cannot override from',

[AmazingAng]

Ethers Version

5.6.9

Search Terms

callstatic

Describe the Problem

I try to use callStatic and override the msg.sender using following code in our Ethers.js tutorial:

const contractWETH = new ethers.Contract(addressWETH, abiWETH, signer)
const tx = await contractWETH.callStatic.transfer("vitalik.eth", ethers.utils.parseEther("100000"), {from: "vitalik.eth"})

I expect it to work, but it throws following

  reason: 'Contract with a Signer cannot override from',
  code: 'UNSUPPORTED_OPERATION',
  operation: 'overrides.from'

If I change signer to provider, it works perfectly. But why users can't override from using callStatic with a signer?

Code Snippet

const contractWETH = new ethers.Contract(addressWETH, abiWETH, signer)
const tx = await contractWETH.callStatic.transfer("vitalik.eth", ethers.utils.parseEther("100000"), {from: "vitalik.eth"})

Contract ABI

const abiWETH = [
    "function balanceOf(address) public view returns(uint)",
    "function transfer(address, uint) public returns (bool)",
];

Errors

Error: Contract with a Signer cannot override from (operation="overrides.from", code=UNSUPPORTED_OPERATION, version=contracts/5.6.2)
    at Logger.makeError (/Users/liang/Documents/Fight for PHD/work/MiniSolidity/repo/WTFEthers/node_modules/@ethersproject/logger/lib/index.js:233:21)
    at Logger.throwError (/Users/liang/Documents/Fight for PHD/work/MiniSolidity/repo/WTFEthers/node_modules/@ethersproject/logger/lib/index.js:242:20)
    at /Users/liang/Documents/Fight for PHD/work/MiniSolidity/repo/WTFEthers/node_modules/@ethersproject/contracts/lib/index.js:175:48
    at step (/Users/liang/Documents/Fight for PHD/work/MiniSolidity/repo/WTFEthers/node_modules/@ethersproject/contracts/lib/index.js:48:23)
    at Object.next (/Users/liang/Documents/Fight for PHD/work/MiniSolidity/repo/WTFEthers/node_modules/@ethersproject/contracts/lib/index.js:29:53)
    at /Users/liang/Documents/Fight for PHD/work/MiniSolidity/repo/WTFEthers/node_modules/@ethersproject/contracts/lib/index.js:23:71
    at new Promise (<anonymous>)
    at __awaiter (/Users/liang/Documents/Fight for PHD/work/MiniSolidity/repo/WTFEthers/node_modules/@ethersproject/contracts/lib/index.js:19:12)
    at /Users/liang/Documents/Fight for PHD/work/MiniSolidity/repo/WTFEthers/node_modules/@ethersproject/contracts/lib/index.js:172:63
    at processTicksAndRejections (node:internal/process/task_queues:96:5) {
  reason: 'Contract with a Signer cannot override from',
  code: 'UNSUPPORTED_OPERATION',
  operation: 'overrides.from'
}

Environment

node.js (v12 or newer)

Environment (Other)

No response

[ricmoo]

This is very intentional.

A contract attached to a Signer performs all its operations (including reads) as that Signer. This prevents mistakes from accidentally passing in from for a request and getting a result that would not reflect that Signer.

A contract connected to a provider has no strong attachment to a specific account, so it allows overriding it.

Another method I would recommend is using contract.connect(fromAddress).transfer.staticCall(…). This highlights the value of locking in a Signer; the instance returned from contract.connect(fromAddress) can now be passed to another function which accepts a Contract object, and all operations performed by that function would “creep” outside the operations as that Signer.

When using connect with a string, a VoidSigner is automatically created and attached to the new instance.

Does that make sense? :)

[AmazingAng]

Thanks, ricmoo. It's a very detailed answer and solves my problem.
Is it contract.connect(fromAddress).staticCall.transfer(…)?

[ricmoo]

Oh yes, sorry. I spend a lot of time in the v6 branch these days, which has the order flipped. :)

[AmazingAng]

I see, seems alot gonna change. I will keep the tutorials update.
Also, is there doc for v6? We might be able to translate it to Chinese.

[Haianh9999]

@ricmoo @AmazingAng I'm having the same problem.
When calling the approve function I want the signer address to be different from the from address. Please help me

[zemse]

I want the signer address to be different from the from address.

You need to create signer of the different from addresss and connect it to the contract.

contract.connect(differentSigner).approve(...);

However, this will allow spending of tokens of the different from addresss.

const contract = new Contract(addr, abi, signer);
contract.connect(differentSigner).approve(...);
// below works same as above
const contract = new Contract(addr, abi, differentSigner);
contract.approve(...);

[Haianh9999]

@zemse I have 2 wallet wallet A without ETH I want to pay the approval fee with wallet B. What should I do?

[zemse]

In this case, ERC20 permit function should be used. I think you created another issue for this, were you able to achieve what you wanted using the permit?

[Haianh9999]

This is my code
` const contract = new Contract(tyenAddress, Erc20Abi, signer);

  const txApprove = await contract
    .connect('0x6c8a46A2b3403479c29209196D3D666Da2f3eba8')
    .callStatic.approve(multiCallAddress, ethers.constants.MaxUint256);`

[Haianh9999]

txApprove return true