FundMe Smart Contract Project

FundMe is a Solidity smart contract that allows users to send Ether to a decentralized funding pool with enforced minimum contributions. Only the contract owner can withdraw funds after the funding period ends. This project includes comprehensive tests, deployment scripts, and interaction tools.

Features

• 💰 Accept ETH contributions with minimum USD value enforcement
• 🔒 Owner-only withdrawal functionality
• 📊 Tracks individual funders and their contributions
• ⏱️ Time-limited funding period (bonus feature)
• 🔁 User refund capability before deadline (bonus feature)
• 🧪 Comprehensive test suite with Foundry
• 🤖 Automated deployment and interaction scripts

Prerequisites

• Go (v1.19+)
• Foundry
• Ganache CLI
• solc
• abigen

Project Structure

fundme-project/
├── contracts/              
│   ├── FundMe.sol
│   └── MockV3Aggregator.sol
├── pkg/                   
│   └── contracts/generated/
├── cmd/                    
│   ├── deploy/
│   │   └── main.go
│   ├── fund/
│   │   └── main.go
│   ├── withdraw/
│   │   └── main.go
│   ├── refund/
│   │   └── main.go
│   └── status/            
│       └── main.go
├── test/                   
│   └── fundme_test.go
├── Makefile                
└── .env.example            

Getting Started

1. Clone the repository

git clone https://github.com/your-username/fundme-project.git
cd fundme-project

2. Set up environment

cp .env.example .env
# Edit .env with your private key from ganache

3. Install dependencies,compile-contracts,generate-bindings

make setup

4. Start local blockchain

make start-ganache

Usage

Deploy the contract

make deploy

Example output:

MockV3Aggregator deployed at: 0x5FbDB2315678afecb367f032d93F642f64180aa3
MockV3Aggregator transaction hash: 0x7a9e8e1d6a7e5d4c3b2a1f0e9d8c7b6a5a4b3c2d1e0f9a8b7c6d5e4f3a2b1c0d
FundMe contract deployed at: 0xe7f1725E7734CE288F8367e1Bb143E90bb3F0512
FundMe transaction hash: 0x6a5a4b3c2d1e0f9a8b7c6d5e4f3a2b1c0d9e8f7a6b5c4d3e2f1a0b9c8d7e6f5d4
Save this contract address to your .env file:
CONTRACT_ADDRESS=0xe7f1725E7734CE288F8367e1Bb143E90bb3F0512

Fund the contract (send ETH)

make fund

Example output:

Funding transaction hash: 0x3a2b1c0d9e8f7a6b5c4d3e2f1a0b9c8d7e6f5d4c3b2a1f0e9d8c7b6a5a4b3c2d1
Successfully funded the contract with 0.1 ETH!

Withdraw funds (owner only)

make withdraw

Example output:

Withdrawal transaction hash: 0xf1a0b9c8d7e6f5d4c3b2a1f0e9d8c7b6a5a4b3c2d1e0f9a8b7c6d5e4f3a2b1c0d
Successfully withdrew all funds from the contract!

Refund contributions

make refund

Example output:

Refund transaction hash: 0xa74dbc595d22d99d341425ce39ddade6440433270ce84c11250a1f2bf20a2e11
Successfully processed refund!

1. Funding Validation:

   • ✅ Funding with sufficient ETH (meets $5 minimum)
   • ✅ Funding with insufficient ETH (properly reverts)

2. Withdrawal Functionality:

   • ✅ Owner withdrawal after funding period ends
   • ❌ Non-owner withdrawal attempts (properly reverts)
   • ✅ Multiple funders withdrawal with state reset

3. Advanced Features:

   • ✅ Refund functionality during funding period
   • ✅ Time-based restrictions enforcement
   • ✅ Funder tracking and state management

Check contract status

make status

Example output:

📊 FundMe Contract Status
=========================
👤 Owner: 0x90F8bf6A479f320ead074411a4B0e7944Ea8c9C1
💰 Balance: 0.100000 ETH
⏱️ Funding Deadline: Mon, 26 Jun 2023 14:30:45 UTC
🟢 Time Remaining: 6d 23h 59m
👥 Funders: 1
=========================

Test Execution

# Run all tests
make test

# Sample output
=== RUN   TestFundMeContract
=== RUN   TestFundMeContract/Funding_with_sufficient_ETH
=== RUN   TestFundMeContract/Funding_with_insufficient_ETH
=== RUN   TestFundMeContract/Owner_withdrawal_with_single_funder
=== RUN   TestFundMeContract/Non-owner_withdrawal_attempt
=== RUN   TestFundMeContract/Multiple_funders_and_withdrawal
=== RUN   TestFundMeContract/Refund_functionality
--- PASS: TestFundMeContract (0.04s)
    --- PASS: TestFundMeContract/Funding_with_sufficient_ETH (0.00s)
    --- PASS: TestFundMeContract/Funding_with_insufficient_ETH (0.00s)
    --- PASS: TestFundMeContract/Owner_withdrawal_with_single_funder (0.00s)
    --- PASS: TestFundMeContract/Non-owner_withdrawal_attempt (0.00s)
    --- PASS: TestFundMeContract/Multiple_funders_and_withdrawal (0.01s)
    --- PASS: TestFundMeContract/Refund_functionality (0.00s)
PASS

Test Features

• ⏱️ Time manipulation for funding period validation
• 🔄 State reset verification after operations
• ⛽ Gas optimization checks
• 🔐 Permission testing (owner vs non-owner)
• 💰 Balance verification pre/post transactions
• 🧪 Isolated test environments with contract redeployment

### Clean build artifacts    
```bash
make clean

Key Commands

Command	Description
make setup	Install dependencies & generate bindings
make start-ganache	Start local Ethereum blockchain
make deploy	Deploy contract to local network
make fund	Send ETH to contract
make refund	Refund contributions
make withdraw	Withdraw funds (owner only)
make status	NEW: Check contract status
make test	Run all tests
make clean	Remove build artifacts

## Smart Contract Features

### Core Functionality
- **Payable `fund()` function**: Accepts ETH contributions
- **Owner-restricted `withdraw()`**: Only contract deployer can withdraw
- **Minimum USD contribution**: Enforced using price feeds
- **Funder tracking**: Records all contributors and amounts

### Advanced Features
- **Mock price feeds**: For local development and testing
- **Funding deadline**: Time-limited contribution period
- **Refund mechanism**: Allows contributors to reclaim funds before deadline

## Testing

Run the comprehensive test suite:
```bash
make test

Test coverage includes:

• Successful funding transactions
• Minimum contribution enforcement
• Owner withdrawal functionality
• Non-owner withdrawal prevention
• Funder tracking and state reset
• Time-based restrictions (bonus features)
• Refund functionality (bonus features)

License

This project is licensed under the MIT License - see the LICENSE file for details.