AVAX-PROOF-Module-1

Welcome to the AVAX-PROOF-Module-1 for the Metacrafters

Getting Started

Prerequisites

• Unix Computer (MacOS or Linux) or WSL in Windows
• Remix IDE
• Metamask

Setting Up Your EVM Subnet on Avalanche

1. Deploy your custom EVM subnet using the Avalanche CLI. Refer to the guide and Avalanche documentation for detailed instructions.

2. Define your native currency as an ERC20 token. This will be the in-game currency for your DeFi Kingdom clone.

3. Connect your EVM subnet to Metamask.

Deploying Smart Contracts

ERC20 Token Contract

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;

contract ERC20 {
    uint public totalSupply;
    mapping(address => uint) public balanceOf;
    mapping(address => mapping(address => uint)) public allowance;
    string public name = "RUDRATOKEN";
    string public symbol = "RTN";
    uint8 public decimals = 18;

    event Transfer(address indexed from, address indexed to, uint value);
    event Approval(address indexed owner, address indexed spender, uint value);

    function transfer(address recipient, uint amount) external returns (bool) {
        balanceOf[msg.sender] -= amount;
        balanceOf[recipient] += amount;
        emit Transfer(msg.sender, recipient, amount);
        return true;
    }

    function approve(address spender, uint amount) external returns (bool) {
        allowance[msg.sender][spender] = amount;
        emit Approval(msg.sender, spender, amount);
        return true;
    }

    function transferFrom(
        address sender,
        address recipient,
        uint amount
    ) external returns (bool) {
        allowance[sender][msg.sender] -= amount;
        balanceOf[sender] -= amount;
        balanceOf[recipient] += amount;
        emit Transfer(sender, recipient, amount);
        return true;
    }

    function mint(uint amount) external {
        balanceOf[msg.sender] += amount;
        totalSupply += amount;
        emit Transfer(address(0), msg.sender, amount);
    }

    function burn(uint amount) external {
        balanceOf[msg.sender] -= amount;
        totalSupply -= amount;
        emit Transfer(msg.sender, address(0), amount);
    }
}

Functions

1. transfer

function transfer(address recipient, uint amount) external returns (bool);

Transfers a specified amount of tokens from the sender's address to the recipient's address.

2. approve

function approve(address spender, uint amount) external returns (bool);

Allows the spender to withdraw a specified amount of tokens from the owner's address. Must be called before transferFrom.

3. transferFrom

function transferFrom(address sender, address recipient, uint amount) external returns (bool);

Transfers a specified amount of tokens from the sender's address to the recipient's address. The spender must have been approved by the owner using the approve function.

4. balanceOf

function balanceOf(address account) external view returns (uint);

Returns the balance of tokens held by a specific address.

5. allowance

function allowance(address owner, address spender) external view returns (uint);

Returns the remaining number of tokens that the spender is allowed to withdraw from the owner.

6. mint

function mint(uint amount) external;

Creates a specified amount of new tokens. Only callable by the contract owner.

7. burn

function burn(uint amount) external;

Compile and deploy this contract using Remix. Adjust parameters such as name, symbol, and decimals during deployment.

Vault Contract

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.17;

interface IERC20 {
    function totalSupply() external view returns (uint);
    function balanceOf(address account) external view returns (uint);
    function transfer(address recipient, uint amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint);
    function approve(address spender, uint amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint amount) external returns (bool);

    event Transfer(address indexed from, address indexed to, uint value);
    event Approval(address indexed owner, address indexed spender, uint value);
}

contract Vault {
    IERC20 public immutable token;

    uint public totalSupply;
    mapping(address => uint) public balanceOf;

    constructor(address _token) {
        token = IERC20(_token);
    }

    function _mint(address _to, uint _shares) private {
        totalSupply += _shares;
        balanceOf[_to] += _shares;
    }

    function _burn(address _from, uint _shares) private {
        totalSupply -= _shares;
        balanceOf[_from] -= _shares;
    }

    function deposit(uint _amount) external {
        uint shares;
        if (totalSupply == 0) {
            shares = _amount;
        } else {
            shares = (_amount * totalSupply) / token.balanceOf(address(this));
        }

        _mint(msg.sender, shares);
        token.transferFrom(msg.sender, address(this), _amount);
    }

    function withdraw(uint _shares) external {
        uint amount = (_shares * token.balanceOf(address(this))) / totalSupply;
        _burn(msg.sender, _shares);
        token.transfer(msg.sender, amount);
    }
}

Deploy the Vault contract, ensuring you provide the address of the ERC20 token contract as a parameter.

Metamask Configuration

Network name : mySubnet
New RPC URL : http://127.0.0.1:9650/ext/bc/MYp2AYrY5iZGADK17is2L9Lg34i99w3F5WVX2nccXeRwpDJ6v/rpc
Chain ID : 313225
Currency symbol : RYD

Testing Your Application

1. Use Remix to interact with the deployed smart contracts.
2. Test functions like minting, burning, depositing, and withdrawing to simulate in-game activities.
3. Confirm transactions on Metamask.