ethers.js – Fixing Overflow Error When Passing Wei Value to EIP712 _signTypedData

eip712ethers.jsoverflow

    const domainSeparator = {
        chainId: 5
    };
    
    const TestInfo = [
        { name: 'contractAddress', type: 'address' },
        { name: 'fee', type: 'uint256' }
      ];

    const data = {
        contractAddress: '.....',     
        airdropFee: 52009946125155410 // wei value
    };
    
    const signature = await signer._signTypedData(domainSeparator, { TestInfo }, data);

reason: 'overflow',
code: 'NUMERIC_FAULT',
fault: 'overflow',
operation: 'BigNumber.from',
value: 52009946125155410

solidity function takes uint256 wei value for weth amount as an argument, so I'm sending that number but getting overflow error. How do I fix that?

Best Answer

Your value 52009946125155410 is above the maximum integer safely representable as a Number type in JavaScript: 9007199254740991 so ethers.js throws an error.

Just pass it as a string :

airdropFee: "52009946125155410" // wei value

And it should be fine.

Related Solutions

Ethers.js BigNumber Overflow – How to Use a Contract with Wei

The string "2e+21" is not valid for the BigNumber class.

JavaScript uses IEEE 754 numbers, which means any value above around 0.009 would suffer precision loss, and Ethereum is quite picky about numbers not being approximate.

You should use strings for large values, or use the convenience functions provided for converting units, such as ethers.utils.parseEther("1.0") which handles string values.

Here is more info on why you need Big Number: https://docs.ethers.io/v5/api/utils/bignumber/#BigNumber--notes-safenumbers

Ethers.js – How to Fix Overflow Errors in EthersJS

This is your code rewritten using BigNumer (I haven't tested it)

const { BigNumber } = require("ethers")

    const decimals = await contract.decimals()
    const DECIMAL = BigNumber.from(10).pow(decimals)
    console.log(DECIMAL.toString())

    const transferAmount = BigNumber.from(100000).mul(DECIMAL)
    console.log(transferAmount.toString())


    console.log(`Whale tracker started!\nListening for large transfer on ${name}`)

    contract.on('Transfer',(from, to, value,  data)=>{
        if(value.gte(transferAmount)){
            console.log(`Trasnaction ${from} to ${to} was sent with a value of ${value.div(DECIMAL).toString()} of ${symbol}\n TransactionHash ${data.transactionHash}`)

The max number represented by javascript is around 0.009*10**18, that's why we almost always need to use the BigNumber library when dealing with ether or token amounts.

Converting from a normal number to BigNumber is done like this

BigNumber.from(100)

then we can use math operations between BigNumbers

a.add(b)  <==>  a+b
a.mul(b)  <==>  a*b
...

all listed here https://docs.ethers.io/v5/api/utils/bignumber/

Best Answer

Related Solutions

Ethers.js BigNumber Overflow – How to Use a Contract with Wei

Ethers.js – How to Fix Overflow Errors in EthersJS

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