evmcheb / nft-meltdown

NFT candle auctions - A Chainlink hackathon 2021 winner

🕯️ NFT Meltdown

This repository contains the core smart contracts for Meltdown, an NFT candle-auction platform.

Meltdown was written using dapptools, a suite of tools used to develop on Ethereum.

The Meltdown frontend code can be found here.

Meltdown Auction Lifetime

1. Auction Creation

• Seller approves Meltdown to spend ERC721
• Seller calls createAuction specifying auction parameters

2. Bidding

• Buyers can bid on the auction by calling addToBid with some ETH value
• There are two phases of bidding
  • Normal: During the start of the auction, each bid is guaranteed to count
  • Closing: The auction can end at any time during the closing window. So bids are not guaranteed to contribute to the bidder's final amount.

3. Finalisation

• checkUpkeep returns true once the auction is finished.
• This prompts a Chainlink Keeper node to call performUpkeep, which then calls requestRandomness.
• requestRandomness requests a random uint256 from Chainlink VRF.
• VRF calls fulfilRandomness callback in the Meltdown contract, which calls finaliseAuction with the random uint.
• We use the random uint as a fair, uniformally distributed variable to find where the auction ends.

4. Withdraw

• The highest bidder at the point where the auction finalised can withdraw the sellers ERC721
• The ERC721 seller can withdraw the cumulative bid of the auction winner.
• The unsuccessful bidders can withdraw all their bidded ETH.

Installation

First install dapptools

git clone https://github.com/calebcheng00/cl-fall-2021
cd cl-fall-2021
dapp build

Running Tests

This repository contains comprehensive test cases enabled by the comprehensive testing framework in dapptools.

cd into the repository, then run:

dapp test