Estimate gas in ETH from an approve contract - ethereum

I woudlike to estimateGas after an approve contract :
WETH = weth.address;
USDC = usdc.address;
await usdc.approve(addr1, addr2).estimateGas;
When I try this I have this error :
TypeError: usdt.approve(...).estimateGas is not a function

Truffle uses different syntax. You need to pass the function params to the estimateGas(), not to the approve() function.
await usdc.approve.estimateGas(addr1, addr2);
Docs: http://trufflesuite.com/docs/truffle/getting-started/interacting-with-your-contracts#special-methods-on-truffle-contract-objects
Note: Your code defines usdc and then the error message states usdt. I'm assuming that's just a typo while creating the question, unrelated to the original issue.

Related

Override the gasPrice in ethers.js contract interaction

How can I set the gasPrice in a contract interaction using ethers.js? I'm trying to override the gasPrice in the code below:
let txPromise = contract.populateTransaction.runAdventureVRF(0, false, { gasPrice: 800000 })
walletSigner.sendTransaction(txPromise)
and i'm receiving the error transaction underpriced. If i try to log txPromise.overrides it is undefined, which makes me think the gas price is never being set.
docs
additional code
const provider = new ethers.providers.AlchemyProvider('matic', process.env.ALCHEMY_API_KEY)
const wallet = new ethers.Wallet(process.env.PK)
const abi = '[{"inputs":[{"internalType":"uint256","name":"_teamId","type":"uint256"},{"internalType":"bool","name":"_energy","type":"bool"}],"name":"runAdventureVRF","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"nonpayable","type":"function"}]'
const contract = new ethers.Contract(address, abi, provider);
let walletSigner = wallet.connect(provider)
One solution is to add the gas price as an override to your transaction:
walletSigner.sendTransaction(txPromise, {gasPrice: ethers.utils.parseUnits('100', 'gwei'), gasLimit: 1000000});
This is the only solution I could find as getGasPrice() and estimateGas() were returning a empty json array. I don't know if it has to do with the provider (alchemy) or why those are failing.
The specific syntax to override the gas price is here:
Ethers Override Transaction Gas Price Manually
It's also in the following Ethers docs, but not as clear (if you don't know the syntax):
Ethers Contract Functions Send
At the time of this post, the default gas value of all my transactions is 1.5 gwei which is nowhere near enough on the matic network. This will also hang up the transaction indefinitely until you send a new transaction with the same nonce value. Even if you resolve your gas issue, until you deal with the hung transaction, other transactions will stack up behind it.
If you just want to increase gasLimit by a certain amount, you can make a helper function to do so:
const increaseGasLimit = (estimatedGasLimit: BigNumber) => {
return estimatedGasLimit.mul(130).div(100) // increase by 30%
}
And use it like this:
const estimatedGas = await contract.estimateGas.method(args)
const tx = await contract.method(args, { gasLimit: increaseGasLimit(estimatedGas) })

How do I solve the Smart Contract error "returned values aren't valid"?

I am trying to read basic information from a smart contract using web3.js (GRAPH Token):
https://etherscan.io/address/0xc944e90c64b2c07662a292be6244bdf05cda44a7#code
This is my super simple react web3.js setup:
import Web3 from 'web3';
...
useEffect(() => {
const start = async () => {
const web3 = new Web3('https://bsc-dataseed1.binance.org:443')
const abi = [{"inputs":[{"internalType":"uint256","name":"_initialSupply","type":"uint256"}],"stateMutability":"nonpayable","type":"constructor"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"owner","type":"address"},{"indexed":true,"internalType":"address","name":"spender","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"account","type":"address"}],"name":"MinterAdded","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"account","type":"address"}],"name":"MinterRemoved","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"}],"name":"NewOwnership","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"}],"name":"NewPendingOwnership","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"internalType":"address","name":"from","type":"address"},{"indexed":true,"internalType":"address","name":"to","type":"address"},{"indexed":false,"internalType":"uint256","name":"value","type":"uint256"}],"name":"Transfer","type":"event"},{"inputs":[],"name":"acceptOwnership","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_account","type":"address"}],"name":"addMinter","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"owner","type":"address"},{"internalType":"address","name":"spender","type":"address"}],"name":"allowance","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"approve","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"}],"name":"balanceOf","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"burn","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"account","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"burnFrom","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"decimals","outputs":[{"internalType":"uint8","name":"","type":"uint8"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"subtractedValue","type":"uint256"}],"name":"decreaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"governor","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"spender","type":"address"},{"internalType":"uint256","name":"addedValue","type":"uint256"}],"name":"increaseAllowance","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_account","type":"address"}],"name":"isMinter","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_to","type":"address"},{"internalType":"uint256","name":"_amount","type":"uint256"}],"name":"mint","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"name","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"","type":"address"}],"name":"nonces","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"pendingGovernor","outputs":[{"internalType":"address","name":"","type":"address"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"_owner","type":"address"},{"internalType":"address","name":"_spender","type":"address"},{"internalType":"uint256","name":"_value","type":"uint256"},{"internalType":"uint256","name":"_deadline","type":"uint256"},{"internalType":"uint8","name":"_v","type":"uint8"},{"internalType":"bytes32","name":"_r","type":"bytes32"},{"internalType":"bytes32","name":"_s","type":"bytes32"}],"name":"permit","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_account","type":"address"}],"name":"removeMinter","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"renounceMinter","outputs":[],"stateMutability":"nonpayable","type":"function"},{"inputs":[],"name":"symbol","outputs":[{"internalType":"string","name":"","type":"string"}],"stateMutability":"view","type":"function"},{"inputs":[],"name":"totalSupply","outputs":[{"internalType":"uint256","name":"","type":"uint256"}],"stateMutability":"view","type":"function"},{"inputs":[{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transfer","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"sender","type":"address"},{"internalType":"address","name":"recipient","type":"address"},{"internalType":"uint256","name":"amount","type":"uint256"}],"name":"transferFrom","outputs":[{"internalType":"bool","name":"","type":"bool"}],"stateMutability":"nonpayable","type":"function"},{"inputs":[{"internalType":"address","name":"_newGovernor","type":"address"}],"name":"transferOwnership","outputs":[],"stateMutability":"nonpayable","type":"function"}]
const address = '0xc944E90C64B2c07662A292be6244BDf05Cda44a7'
const contract = new web3.eth.Contract(abi, address)
console.log(contract);
const i = await contract.methods.getName().call()
console.log(i); // => ERROR
}
start()
}, [])
And it throws error:
Error: Returned values aren't valid, did it run Out of Gas? You might also see this error if you are not using the correct ABI for the contract you are retrieving data from, requesting data from a block number that does not exist, or querying a node which is not fully synced.
This is a known and misleading error which usually means that the address or the contract abi is invalid but I verified it is correct.
I researched this error for two days but didn't manage to solve this issue... any suggestions?
You're trying to interact with an Ethereum contract, using a BSC (Binance Smart Chain) Web3 provider (in your case https://bsc-dataseed1.binance.org:443). This results in trying to call the getName() function on the BSC address (which doesn't contain any contract).
Ethereum and BSC are different networks, unrelated to each other.
Solution: Use an Ethereum mainnet provider (for example Infura is widely used).

Ethereum Contract call methods return insufficient gas message?

The call methods on a contract deployed to mainnet are erroring with insufficient gas messages.
{
code: -32000,
message: 'err: insufficient funds for gas * price + value: address <address> have 27795556348606292 want 420361420000000000 (supplied gas 894386)'
}
On Kovan network, the call methods are working fine. But on Mainnet they are returning the above.
Since call methods require no gas, I'm not sure what the issue is.
$ truffle(mainnet)> c = await EthText.deployed()
$ truffle(mainnet)> c.dapp_name()
dapp_name is a call method
contract MyContract {
string public dapp_name = "Eth Text";
What would cause this error?

web3 calls Solidity contract function with extra parameter?

In the http://truffleframework.com/tutorials/pet-shop example, there is the following contract, and the function adopt(uint petId) has only one parameter.
contract Adoption {
address[16] public adopters;
function adopt(uint petId) public returns (uint) {
require(petId >= 0 && petId <= 15);
adopters[petId] = msg.sender;
return petId;
}
function getAdopters() public returns (address[16]) {
return adopters;
}
}
However, in the javascript code app.js, the handleAdopt function call the contract function using the following code.
App.contracts.Adoption.deployed().then(function(instance) {
adoptionInstance = instance;
return adoptionInstance.adopt(petId, {from: account});
})
The function is called with the extra object {from: account}. Why? And is this parameter discarded in the solidity code?
BTW, there is an undefined global variable web3? Is the value be assigned by the MetaMask extension?
That is the transactionObject which describes general information about all transaction calls (gas limit, price, amount of ether to send, etc.). The JS code you posted is using the web3 library. That's not the direct call to the contract API. The web3 library converts it to an RPC. The transactionObject comes after all of the contract parameters. There is another parameter that comes after which is the callback with the results of the contract call (see here).
These are all of the options for the transactionobject described from the docs:
from: String - The address for the sending account. Uses the web3.eth.defaultAccount property, if not specified.
to: String - (optional) The destination address of the message, left undefined for a contract-creation transaction.
value: Number|String|BigNumber - (optional) The value transferred for the transaction in Wei, also the endowment if it's a contract-creation transaction.
gas: Number|String|BigNumber - (optional, default: To-Be-Determined) The amount of gas to use for the transaction (unused gas is refunded).
gasPrice: Number|String|BigNumber - (optional, default: To-Be-Determined) The price of gas for this transaction in wei, defaults to the mean network gas price.
data: String - (optional) Either a byte string containing the associated data of the message, or in the case of a contract-creation transaction, the initialisation code.
nonce: Number - (optional) Integer of a nonce. This allows to overwrite your own pending transactions that use the same nonce.

How to detect if an Ethereum address is an ERC20 token contract?

If I only get an Ethereum address from the input, is there a way to find out whether it matches the ERC20 token standard?
ERC165 tackles this problem, but, unfortunately, most ERC20 implementations don't support it (as of Nov 2018, at least OpenZeppelin doesn't). This means that you could try calling the supportsInterface function, but it would revert anyway and you'd rather complicate things.
Nevertheless, here's how it's defined in ERC721:
bytes4 private constant _InterfaceId_ERC721 = 0x80ac58cd;
/*
* 0x80ac58cd ===
* bytes4(keccak256('balanceOf(address)')) ^
* bytes4(keccak256('ownerOf(uint256)')) ^
* bytes4(keccak256('approve(address,uint256)')) ^
* bytes4(keccak256('getApproved(uint256)')) ^
* bytes4(keccak256('setApprovalForAll(address,bool)')) ^
* bytes4(keccak256('isApprovedForAll(address,address)')) ^
* bytes4(keccak256('transferFrom(address,address,uint256)')) ^
* bytes4(keccak256('safeTransferFrom(address,address,uint256)')) ^
* bytes4(keccak256('safeTransferFrom(address,address,uint256,bytes)'))
*/
Although it's not guaranteed for all implementations to define the interface id, there's a higher chance it will work in the case of ERC721, given the fact the community agreed on applying ERC165 right from the get-go. If the return value of the query below is true, then it means you have a compliant contract, otherwise just revert the transaction.
// you can call this in your contracts
IERC721(contractAddress).supportsInterface(0x80ac58cd)
Also, a useful resource for manually checking the bytes4 of a given method is 4byte.directory
If you are asking about off-chain, so use these functions:
getContract(url, smartContractAddress){
const Web3Eth = require('web3-eth');
const abi_ = this.getABI();
const web3Eth = new Web3Eth(Web3Eth.givenProvider || url);
return new web3Eth.Contract(abi_, smartContractAddress);
}
async getERCtype(contract){
const is721 = await contract.methods.supportsInterface('0x80ac58cd').call();
if(is721){
return "ERC721";
}
const is1155 = await contract.methods.supportsInterface('0xd9b67a26').call();
if(is1155){
return "ERC1155";
}
return undefined;
}
getABI(){
return [
{"constant":true,"inputs": [
{"internalType":"bytes4","name": "","type": "bytes4"}],
"name": "supportsInterface",
"outputs": [{"internalType":"bool","name": "","type": "bool"}],
"payable": false,"stateMutability":"view","type": "function"}
];
}
like this:
const contract = getContract(url, smartContractAddress);
const type = await getERCtype(contract);
console.log(type);
There are many possible ways to achieve this. One possible quick and dirty solution is to check if a ERC20 function exists on the contract address by calling the following:
eth.call({to:contractAddress, data:web3.sha3("balanceOf(address)")})
A non-ERC20 will return a 'null' 0x hex response whereas an ERC20 will give you a 32byte uint, in this case 0 but if you provide an address in the data then it will give you the actual token balance for that address.
This is not a guaranteed way of determining a contract is ERC20 since other contracts may expose the same function, however it is a quick and easy check. You could add additional calls on totalSupply() etc. for more confirmation.
the question states that given an Ethereum address, is this an Ethereum contract address or not?
First thing, you have to decide if this address is a contract address or an externally owned account address. How to find out if an Ethereum address is a contract
If it is a contract address, then you can only get the bytecode that is stored in the blockchain. Now you have to reverse engineer the bytecode to get the contract functions but this is almost impossible. There are some decompilers but they are not perfectly creating the contract code from the bytecode.
ERC165 just checks if the current contract signature supports the given interfaceId or not. Since you have only ethereum address, this will not help in this question.