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Examples

This section provides practical examples and complete workflows to help you get the most out of Mega CLI.

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Smart Contract Development Workflow

This example shows a complete workflow for developing, testing, and deploying a smart contract to the Mega testnet.

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1. Initialize a Foundry Project

# Create a new Foundry project
mega init my-contract-project --foundry

# Navigate to the project
cd my-contract-project

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2. Create a Simple Contract

Create a file named src/Counter.sol: 
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

contract Counter {
    uint256 private counter;
    
    event CounterIncremented(address indexed user, uint256 newValue);
    
    function getCount() public view returns (uint256) {
        return counter;
    }
    
    function increment() public {
        counter += 1;
        emit CounterIncremented(msg.sender, counter);
    }
}

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3. Write a Test

Create a file named test/Counter.t.sol: 
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.20;

import "forge-std/Test.sol";
import "../src/Counter.sol";

contract CounterTest is Test {
    Counter public counter;
    
    function setUp() public {
        counter = new Counter();
    }
    
    function testInitialCount() public {
        assertEq(counter.getCount(), 0);
    }
    
    function testIncrement() public {
        counter.increment();
        assertEq(counter.getCount(), 1);
    }
    
    function testEmitsEvent() public {
        vm.expectEmit(true, false, false, true);
        emit Counter.CounterIncremented(address(this), 1);
        counter.increment();
    }
}

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4. Compile and Test

# Compile contracts
mega compile

# Run tests
forge test

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5. Deploy Locally

You can use the mega deploy command like so: 
# Deploy to local network
mega deploy src/Counter.sol:Counter --broadcast
For more complex deployment scenarios, you can still create deployment scripts in the script/ directory, but for this example, we’ll use the direct deployment approach.

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6. Create an Account

# Create a new account
mega account create
# > Enter a name for your wallet: dev
# > Enter a password: ********

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7. Get Testnet Tokens

# Request tokens from the faucet
mega faucet --account <account-name>

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8. Deploy to Testnet

# Deploy to Mega testnet
mega deploy src/Counter.sol:Counter --testnet --broadcast --account <account-name>

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Full-Stack App Development Workflow

This example demonstrates how to create and run a full-stack application.

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1. Initialize a Full-Stack Project

# Create a new full-stack project
mega init my-dapp

# Navigate to the project
cd my-dapp

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2. Start the Development Environment

# Start both the Foundry and frontend environments
mega dev

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3. Deploy a Contract to the Local Chain

In a new terminal: 
# Compile contracts
mega compile

# Deploy to local Anvil chain (uses default Anvil private key)
mega deploy foundry-app/src/GmegaCounter.sol:GmegaCounter --broadcast

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4. Connect the Frontend to the Contract

Update next-app/src/constants/index.js with your contract address: 
export const CONTRACT_ADDRESSES = {
  GmegaCounter: "0x5FbDB2315678afecb367f032d93F642f64180aa3" // Replace with your deployed address
};

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5. Test the Application

After starting the development environment with mega dev, you can:
  1. Visit http://localhost:3000/gmega in your browser
  2. Connect your wallet
  3. Interact with the deployed contract