블록체인/Solidity

스마트컨트렉트 테스트에 Infinite Approve 적용하기

체인의정석 2022. 7. 25. 18:57
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먼저 approve를 무한대로 해주는 infiniteApprove의 경우

https://ethereum.stackexchange.com/questions/86928/does-the-approve-function-on-an-erc20-token-need-to-be-run-once-or-before-every

 

Does the approve function on an ERC20 token need to be run once or before every relevant transaction?

I understand that an ERC20's approve() function has to be run before the token can be sent to another contract. But is this a one-time approval for msg.sender to be granted an approval status or do...

ethereum.stackexchange.com

해당 글에서 힌트를 얻을 수 있었다.

 

decimal = 18;
const infiniteVal: number = 2 ** 256 - 1;
const infiniteValBN: BigNumber = BigNumber.from(infiniteVal);
const bigIntTest: BigNumber = ethers.utils.parseUnits(
  infiniteValBN.toString(),
  decimal
);

그 결과 이런식으로 한번 테스트를 해봤는데 결과는 

  reason: 'overflow',
  code: 'NUMERIC_FAULT',
  fault: 'overflow',
  operation: 'BigNumber.from',
  value: 1.157920892373162e+77

이렇게 나왔다.

 

https://stackoverflow.com/questions/65994914/how-to-approve-a-token-for-spending-on-uniswap-router-contract

 

How to approve a token for spending on (Uniswap router contract)

Im trying to approve and later on swap my tokens on uniswap via web3py code. I am also using infura, not my own node. However, on both the swap and the approve I run into solidityErrors. The proble...

stackoverflow.com

보니까 web3 에선 위와 같이 되는것 같다.

 

https://github.com/ethers-io/ethers.js/discussions/2814

 

code: 'NUMERIC_FAULT', fault: 'overflow', operation: 'BigNumber.from' · Discussion #2814 · ethers-io/ethers.js

Hello! const tokenID = 96178001019380483532355422451609849948339356991030948866277126174730172245776; const someContract = new ethers.Contract(contractAddress, abi ,account) const result = await so...

github.com

보니까 bigNumber가 에러가 나는 것이므로 이때는 quote를 쓰라고 한다.

하지만 값 자체가 숫자형태로 안나오기 때문에 조금 더 찾아봤다.

https://forum.openzeppelin.com/t/using-the-maximum-integer-in-solidity/3000

 

Using the maximum integer in Solidity

There’s a variety of reasons you might want to know the maximum possible integer in solidity. One common use case is to approve a contract to transfer your tokens on your behalf: tokenContract.approve(exchangeContract, MAX_INT, { from: me }) Here I tell

forum.openzeppelin.com

오픈제플린 포럼에서 서치한 결과

const bigIntTest: BigNumber = ethers.utils.parseUnits(
  "115792089237316195423570985008687907853269984665640564039457584007913129639935",
  0
);
console.log("bigTest >>>", bigIntTest);

이렇게 하면 bignumber를 구할 수 있었다.

 

const bigIntTest: BigNumber = ethers.utils.parseUnits(
  "115792089237316195423570985008687907853269984665640564039457584007913129639935",
  0
);


  it("test inifinite approve", async function () {
    await erc20Token
      .approve(ExampleContract.address, bigIntTest);
    expect(
      await erc20Token.allowance(userA.address, ExampleContract.address)
    ).equal(bigIntTest);

    console.log("approve num", bigIntTest);
  });

 

위와 같이 테스트 코드를 수정하니 infinite approve가 적용되었다.

 

어차피 고정값으로 넣으니 overflow가 나지 않게 처음부터 고정값으로 넣고 그 상태 그대로 bigNumber로 만들어서 입력값과 결과값체크에 사용하면 되는거엿다.

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