Auction

About

• AuctionRepository is the main contract that allows asset owners to create auction (1 per ERC20 asset) for asset standards like ERC20, ERC721, ERC1155, etc.

• Auction contract is a smart contract that allows users (assetOwner, bidder) to:

  • bid for an asset,
  • withdraw the bid amount when a higher bid is placed.
  • claim possession for the asset when the auction is over.
  • reclaim the asset when the auction is over and no one has bid for the asset.

• Auction SC contains all the logic & storage for bidding, withdrawing bid amount, etc.

• The highest bidder automatically becomes the owner of the asset when the auction ends.

• Feedback

  • Drawbacks:
    • Every bidder can bid only once for the given Auction.
    • Auction contract can't be paused directly as it's owned by the AuctionRepository contract, but not EOA. Hence, bugs (if remain) would be open for exploitation by hacker & no way to upgrade.

      Solution: An workaround is to make the owner of AuctionRepository SC same for the Auction SC as well. In this way, the super owner can pause the Auction SC as well in case of bugs discovered in addition to AuctionRepository SC.

    • Factory clone pattern is used to create Auction contract for each asset, which is not gas efficient.
  • Feature:
    • A new bidder when bids for the asset, the previous bidder's bid is refunded. In this way, we won't need any withdraw function.
      • Cons: Additional gas cost for refunding the previous bidder to be paid by the new bidder.
    • Auction contract can be made as a facet of the AuctionRepository proxy contract, which will reduce the gas cost of creating a new auction contract.
    • Each auction would be given a unique id instead of contract address (generated by another contract using create2 function which is a expensive operation).

• Architecture

Relation b/w AuctionRepository & Auction SCs

flowchart LR
AuctionRepository --Asset owner create auction for its asset via `createAuction`--> Auction

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Functions of AuctionRepository SC

flowchart TB
AuctionRepository --create auction for an owned asset--> `createAuction`
AuctionRepository --update record for live Auctions i.e. remove the ones that expired--> `updateLiveAuctions`

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Functions of Auction SC

flowchart TB
Auction --bids for an asset--> `placeBid`
Auction --withdraw bid amount--> `withdrawBid`
Auction --claim Possession--> `claimPossession`
Auction --reclaim Asset--> `reclaimAsset`

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Sequence Diagram for workflow of Auction

sequenceDiagram
AssetOwner->>Asset: approve Transfer of Ownership to AuctionRepository
AssetOwner->>AuctionRepository: `createAuction`
AuctionRepository->>Auction: deployment i.e. contract creation
AuctionRepository->>Auction: initialize
AuctionRepository->>Asset: transferOwnership to Auction SC
Bidder->>Auction: bid for the asset
Bidder->>Auction: withdraw bid amount if bid amount is less than the highest bid
Bidder->>Auction: claim Possession of the asset if bid amount is the highest & auction is expired
AssetOwner->>Auction: reclaim Asset if auction is expired & no bid is placed

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Installation

yarn install

Usage

Build

yarn compile

Contract size

yarn contract-size

Test

yarn test

TypeChain

Compile the smart contracts and generate TypeChain artifacts:

yarn typechain

Lint Solidity

Lint the Solidity code:

yarn lint:sol

Lint TypeScript

Lint the TypeScript code:

yarn lint:ts

Coverage

Generate the code coverage report:

yarn coverage

Report Gas

See the gas usage per unit test and average gas per method call:

REPORT_GAS=true yarn test

Clean

Delete the smart contract artifacts, the coverage reports and the Hardhat cache:

yarn clean

Verify

yarn verify <network_name> <deployed_contract_address> <constructor params>
// TODO: add your own SC arguments or empty
yarn verify <network_name> <deployed_contract_address> --constructor-args verify/auctionrepository.args.ts

For multiple arguments, follow this guide.

Flatten

yarn flatten <contract-filename-w-ext-with-dir> > ./flatten/<contract-filename-w-ext>

Then, the file can be used to upload the code manually (click on 'Contract' tab >> verify and publish) or using script (with Block explorer API as per the network)

Deploy

• Environment variables: Create a .env file with its values in .env.example

localhost

// on terminal-1
npx hardhat node

// on terminal-2
yarn deploy-local

ETH Testnet - Goerli

• Deploy the contracts

yarn deploy-goerli

ETH Mainnet

• Deploy the contracts

yarn deploy-eth