Add balance task

packages/ethernaut-interact/README.md

@@ -34,6 +34,24 @@ This plugin doesn't depend on any other plugins.
 
 This plugin adds the following tasks:
 
+### balance
+
+```
+Usage: hardhat [GLOBAL OPTIONS] interact balance [--token <SPECIAL>] [address]
+
+OPTIONS:
+
+  --token       The token address or ETH (default: "ETH")
+
+POSITIONAL ARGUMENTS:
+
+  address       The address whose balance will be queried
+
+balance: Queries the ETH or TOKEN balance of an address
+
+For global options help run: hardhat help
+```
+
 ### contract
 
 ```

packages/ethernaut-interact/package.json

@@ -1,7 +1,7 @@
 {
   "name": "ethernaut-interact",
   "version": "1.0.3",
-  "description": "Tasks for sending transactions and interacting with contracts",
+  "description": "Tasks for interacting with a network, including sending eth, interacting with contracts, etc",
   "main": "src/index.js",
   "scripts": {
     "build": "npm run install:test",

packages/ethernaut-interact/src/internal/get-contract.js

@@ -0,0 +1,21 @@
+const fs = require('fs')
+const path = require('path')
+
+async function getContract(abiName, address, hre) {
+  return hre.ethers.getContractAt(getAbi(abiName), address)
+}
+
+function getAbi(abiName) {
+  const abisPath = path.join(process.cwd(), 'artifacts', 'interact', 'abis')
+  const filePath = path.join(abisPath, `${abiName}.json`)
+
+  let abi = JSON.parse(fs.readFileSync(filePath, 'utf8'))
+
+  if (abi.abi) abi = abi.abi
+
+  return abi
+}
+
+module.exports = {
+  getContract,
+}

packages/ethernaut-interact/src/tasks/balance.js

@@ -0,0 +1,45 @@
+const output = require('ethernaut-common/src/output')
+const { types } = require('hardhat/config')
+const { getContract } = require('../internal/get-contract')
+
+require('../scopes/interact')
+  .task('balance', 'Queries the ETH or TOKEN balance of an address')
+  .addPositionalParam(
+    'address',
+    'The address whose balance will be queried',
+    undefined,
+    types.string,
+  )
+  .addParam('token', 'The token address or ETH', 'ETH', types.string)
+  .setAction(async ({ address, token }, hre) => {
+    try {
+      let balance
+      if (!token || token === 'ETH') {
+        balance = await getETHBalance(address, hre)
+      } else {
+        balance = await getTokenBalance(address, token, hre)
+      }
+
+      let str = ''
+      str += `Address: ${address}\n`
+      str += `Token: ${token}\n`
+      str += `Balance: ${balance}`
+
+      return output.resultBox(str)
+    } catch (err) {
+      return output.errorBox(err)
+    }
+  })
+
+async function getETHBalance(address, hre) {
+  return hre.ethers.formatEther(await hre.ethers.provider.getBalance(address))
+}
+
+async function getTokenBalance(address, token, hre) {
+  const contract = await getContract('ERC20', token, hre)
+
+  const rawBalance = await contract.balanceOf(address)
+  const decimals = await contract.decimals()
+
+  return hre.ethers.formatUnits(rawBalance, decimals)
+}

packages/ethernaut-interact/test/fixture-projects/basic-project/contracts/ERC20.sol

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.24;
+
+import "./IERC20.sol";
+
+contract ERC20 is IERC20 {
+    event Transfer(address indexed from, address indexed to, uint256 value);
+    event Approval(
+        address indexed owner, address indexed spender, uint256 value
+    );
+
+    uint256 public totalSupply;
+    mapping(address => uint256) public balanceOf;
+    mapping(address => mapping(address => uint256)) public allowance;
+    string public name;
+    string public symbol;
+    uint8 public decimals;
+
+    constructor(string memory _name, string memory _symbol, uint8 _decimals) {
+        name = _name;
+        symbol = _symbol;
+        decimals = _decimals;
+    }
+
+    function transfer(address recipient, uint256 amount)
+        external
+        returns (bool)
+    {
+        balanceOf[msg.sender] -= amount;
+        balanceOf[recipient] += amount;
+        emit Transfer(msg.sender, recipient, amount);
+        return true;
+    }
+
+    function approve(address spender, uint256 amount) external returns (bool) {
+        allowance[msg.sender][spender] = amount;
+        emit Approval(msg.sender, spender, amount);
+        return true;
+    }
+
+    function transferFrom(address sender, address recipient, uint256 amount)
+        external
+        returns (bool)
+    {
+        allowance[sender][msg.sender] -= amount;
+        balanceOf[sender] -= amount;
+        balanceOf[recipient] += amount;
+        emit Transfer(sender, recipient, amount);
+        return true;
+    }
+
+    function _mint(address to, uint256 amount) internal {
+        balanceOf[to] += amount;
+        totalSupply += amount;
+        emit Transfer(address(0), to, amount);
+    }
+
+    function _burn(address from, uint256 amount) internal {
+        balanceOf[from] -= amount;
+        totalSupply -= amount;
+        emit Transfer(from, address(0), amount);
+    }
+
+    function mint(address to, uint256 amount) external {
+        _mint(to, amount);
+    }
+
+    function burn(address from, uint256 amount) external {
+        _burn(from, amount);
+    }
+}

packages/ethernaut-interact/test/fixture-projects/basic-project/contracts/IERC20.sol

@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.24;
+
+interface IERC20 {
+    function totalSupply() external view returns (uint256);
+    function balanceOf(address account) external view returns (uint256);
+    function transfer(address recipient, uint256 amount)
+        external
+        returns (bool);
+    function allowance(address owner, address spender)
+        external
+        view
+        returns (uint256);
+    function approve(address spender, uint256 amount) external returns (bool);
+    function transferFrom(address sender, address recipient, uint256 amount)
+        external
+        returns (bool);
+}

packages/ethernaut-interact/test/fixture-projects/basic-project/contracts/TestToken.sol

@@ -0,0 +1,10 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.24;
+
+import "./ERC20.sol";
+
+contract TestToken is ERC20 {
+    constructor(string memory _name, string memory _symbol, uint8 _decimals) ERC20(_name, _symbol, _decimals) {
+        _mint(msg.sender, 10000 * 10**_decimals);
+    }
+}

packages/ethernaut-interact/test/tasks/balance.test.js

@@ -0,0 +1,66 @@
+const { Terminal } = require('ethernaut-common/src/terminal')
+const getBalance = require('../../src/internal/get-balance')
+
+describe('balance', function () {
+  const terminal = new Terminal()
+
+  let signer
+  let balance
+
+  before('get signers', async function () {
+    const signers = await hre.ethers.getSigners()
+    signer = signers[0]
+  })
+
+  describe('when querying ETH balance', function () {
+    before('rec eth balance', async function () {
+      balance = await getBalance(signer.address)
+    })
+
+    before('make call', async function () {
+      await terminal.run(`npx hardhat interact balance ${signer.address}`)
+    })
+
+    it('shows the address', async function () {
+      terminal.has('Address: ' + signer.address)
+    })
+
+    it('shows the token', async function () {
+      terminal.has('Token: ETH')
+    })
+
+    it('shows the balance', async function () {
+      terminal.has('Balance: ' + balance)
+    })
+  })
+
+  describe('when querying a token balance', function () {
+    let contract
+
+    before('deploy token', async function () {
+      const factory = await hre.ethers.getContractFactory('TestToken')
+      contract = await factory.deploy('Test Token', 'TEST', 16)
+    })
+
+    before('rec eth balance', async function () {
+      const rawBalance = await contract.balanceOf(signer.address)
+      balance = hre.ethers.formatUnits(rawBalance, 16)
+    })
+
+    before('make call', async function () {
+      const token = await contract.getAddress()
+      await terminal.run(
+        `npx hardhat interact balance ${signer.address} --token ${token}`,
+      )
+    })
+
+    it('shows the token', async function () {
+      const token = await contract.getAddress()
+      terminal.has(`Token: ${token}`)
+    })
+
+    it('shows the balance', async function () {
+      terminal.has('Balance: ' + balance)
+    })
+  })
+})