EventEntry

An on-chain guest-list and check-in system built with Solidity and Hardhat.
Users can deploy new EventEntry contracts, index them in a factory, and allow attendees to check in using off-chain signatures. Owners can toggle event status, enforce capacity and timing, and emit detailed events for off-chain tracking.

---

Project Structure

Folder	Purpose
contracts/	Smart contracts (EventEntry.sol, EventEntryFactory.sol)
interfaces/	Public interfaces (IEventEntry.sol, IEventEntryFactory.sol)
scripts/	Deployment & helper scripts
test/	Hardhat tests with Chai & solidity-coverage
coverage/	Coverage reports (solidity-coverage)

---

Smart Contracts

EventEntry

• Constructor

  • constructor(string name, uint32 eventDate, uint32 maxAttendees)
  • Reverts PastEventDate if eventDate <= block.timestamp.
  • Emits EventCreated(name, eventDate, maxAttendees).

• checkIn(bytes signature)

  • Verifies EIP-191 message hash and recovers signer.
  • Errors: InvalidSignatureLength, InvalidSignatureV, EventInactive, EventEnded, AlreadyCheckedIn, CapacityReached.
  • Emits AttendeeCheckedIn(address attendee, uint256 timestamp) and increments attendeeCount.

• setEventStatus(bool active)

  • Only owner can pause/unpause check-ins. Emits EventStatusChanged(active).

• owner()

  • Returns current owner (transferred by factory).

EventEntryFactory

• createEvent(string name, uint32 date, uint32 cap)

  • Deploys a new EventEntry.
  • Transfers ownership to caller.
  • Stores address in allEvents.
  • Emits EventDeployed(address indexed eventAddress, string name, uint32 date, uint32 cap).

• getEventCount() → uint256

• getEvent(uint256 index) → address

  • Reverts "Factory: index out of range" if invalid.

• getAllEvents() → address[]

---

Requirements

• Node.js (>= 18.x)
• pnpm (>= 8.x) or npm (>= 9.x)
• Hardhat (>= 2.12.x)

Install dependencies:

pnpm install

---

Compile Contracts

pnpm hardhat compile

---

Run Tests & Coverage

pnpm hardhat test
pnpm hardhat coverage --show-stack-traces

---

Local Development

1. Start local node

   pnpm hardhat node

2. Deploy to localhost

   pnpm hardhat run scripts/deploy.js --network localhost

3. Open console

   pnpm hardhat console --network localhost

4. Sample interaction

   const [deployer, alice] = await ethers.getSigners();
   
   // Deploy factory
   const factory = await ethers.getContract("EventEntryFactory");
   
   // Create event
   await factory.createEvent(
     "My Gala",
     Math.floor(Date.now() / 1000) + 86400, // tomorrow
     100 // max attendees
   );
   
   const events = await factory.getAllEvents();
   const entryAddr = events[0];
   const eventEntry = await ethers.getContractAt("EventEntry", entryAddr);
   
   // Sign and check in
   const hash = await eventEntry.getMessageHash(alice.address);
   const sig = await deployer.signMessage(ethers.utils.arrayify(hash));
   await eventEntry.connect(alice).checkIn(sig);
   console.log(
     "Total checked in:",
     (await eventEntry.attendeeCount()).toString()
   );

---

Features

• Gas-efficient: immutable state, custom errors.
• Secure: Ownable, CEI pattern, reentrancy-safe.
• Off-chain signatures: no on-chain whitelist.
• Indexed factory: manage multiple events.
• Full test & coverage suite.

---

License

MIT © 2025 Daniel Neris

---

Contributions

Pull Requests and Issues are welcome!
Let’s build the decentralized future together.