https://github.com/seanmayer/auction-smart-contract

Blockchain - Creating an auction smart contract on Ethereum network.
https://github.com/seanmayer/auction-smart-contract

blockchain ethereum

Last synced: 3 months ago
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Blockchain - Creating an auction smart contract on Ethereum network.

• Host: GitHub
• URL: https://github.com/seanmayer/auction-smart-contract
• Owner: seanmayer
• Created: 2021-11-03T06:28:31.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2023-08-24T19:06:51.000Z (over 1 year ago)
• Last Synced: 2025-01-16T03:49:49.896Z (4 months ago)
• Topics: blockchain, ethereum
• Language: Solidity
• Homepage:
• Size: 43 KB
• Stars: 1
• Watchers: 1
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
Auction Smart Contract

Smart Contract for Decentralised Auction, similar to Ebay

- The Auction has an owner (the seller), a start and an end date;

- The owner can cancel the auction, or finalise the auction after its end time

- People are sending ETH by calling a function called `placeBid()`

    - The sender's address and the value sent to the auction will be stored in the mapping variable called bids;

- Users are incentivised to bid the maximum amount

    - Although they are bound to the full amount

    - The contract will be able to automatically bid up to a given amount 

- The `highestBindingBid` is the selling price

- The `highestBidder` the person who won the auction

- When auction completes, the owner gets the `highestBindingBid`

    - Everybody else withdraws their amount

Timestamps

- Timestamp with used for `startBlock` and `endBlock`

- Using the block number to calculate the time because it is safer

- It is noted that the Ethereum block time is roughly 15 seconds

    - Meaning that a new block is created and added to the blockchain

- Based on the blocktime we can calculate when the auction starts and ends

Withdrawal Pattern

- We do not proactively send back the funds to users that did not win the auction. We will use the "withdrawal pattern" instead.

- We should only send ETH to a user when he explicitly requests it

- This is the "withdrawal" pattern and this enables the contract from avoiding re-entrace attacks that could induce unexpected behaviours, including financial loss for users.