Here is an article that explains the issue you are facing with the Metamask function selector not found error when calling a smart contract from your ReactJS application:

Metamask function selector not found error

When developing decentralized applications (dApps), it is common to interact with Ethereum-based contracts using Web3 libraries like Ethers.js. However, one common issue that can occur is the “function selector not found” error in Hardhat node.

In this article, we will explore what causes this error and how you can resolve it when calling a smart contract from your ReactJS application using Metamask.

What is Metamask?

Metamask is an Ethereum wallet that allows users to interact with the Ethereum blockchain. It provides a user interface for managing private keys, sending transactions, and accessing various functions of the Ethereum network.

Function selector not found error in hardhat node

When using Hardhat node to compile and deploy smart contracts, Metamask needs to know which function selector to use to interact with the contract. However, if this information is not provided or is incorrect, you will encounter a “function selector not found” error.

Here is an example of what could go wrong:

import { compile } from 'hardhat-typescript';
const compileContract = async (contractName, ABI) => {
try {
const contract = await compile(contractName);
const binascii = Buffer.from(ABI.map((key) => key.type).join(','));
const selector = '0x' + binascii;
console.log(selector); // This should be a valid function selector
// You are now calling the contract with this selector
await contract.at(selector).call('getTokenDepositAmount', inputToken);
} catch (error) {
console.error(error);
}
};

In this example, selector is a hexadecimal string representing the Ethereum bytecode for the getTokenDepositAmount function. The at() method of the contract object returns a new contract with the specified selector. However, if you are using a smart contract from the Metamask collection, such as the `SushiSwap'' contract, it will have a different bytecode.

There are several reasons why you might encounter thefunction selector not found’ error:

• Incorrect ABI: If the ABI of your smart contract is incorrect or missing certain functions, Metamask will not be able to determine the correct function selector.

• Metamask collection: When using a smart contract from the Metamask collection (e.g. SushiSwap), you need to specify the correct bytecode in the compileContract function.

• Hardhat configuration

  : Your Hardhat project may not have the necessary configuration settings or dependencies to properly compile and deploy your smart contracts.

Troubleshooting

To resolve this error, ensure the following:

• You have correctly compiled and deployed your smart contract using tools like Truffle or Vyper.

• Your Metamask collection is correctly set up and includes all the required functions (e.g. getTokenDepositAmount).

• Your Hardhat project has the necessary dependencies and configuration settings.

Here is an updated example using the SushiSwap contract:

“`javascript

import { compileContract } from ‘hardhat-typescript’;

import ‘@nomiclabs/hardhat-waffle’;

const compile = async (contractName, ABI) => {

try {

const contract = await compile(contractName);

const binascii = Buffer.from(ABI.map((key) => key.type).join(‘,’));

const selector = ‘0x’ + binascii;

// You are now calling the contract with this selector

return await contract.at(selector).call(‘getTokenDepositAmount’, inputToken);

} catch (error) {

console.

Ethereum Sharing Twisted Asyncio Thread