CoinFlip - Double up your ETH!

Table of Contents

• Table of Contents
• Updates
• Description
• Built With
• Getting Started
  • Prerequisites
  • Smart-Contracts Deployment
    • Install the dependencies
    • Deployement
    • Coverage
    • Static Analyzer
  • Config & Client
• Acknowledgments
• Use
  • ⭐️ ... and don't forget to leave a star if you like it! ⭐️

Updates

• 2024/06 - Move from Truffle to Hardhat & Switch to Spolia network & Update to Chainlink VRF 2.5 & compiler to 0.8.20 & Clean contracts/app;
• 2022/07 - Switch to Chainlink VRF v2 & Update solidity compiler version to 0.8.7;
• 2022/12 - Switch to Goerli network v2 & upgrade all deps & Update solc to 0.8.16;

Description

Decentralized application (Dapp), EVM compatible, built as a part of the programming course: Ethereum201 on academy.moralis.com.

The app is a simple coin flip game where you can double up your ETH or lose your bet. The game is based on a smart contract that uses Chainlink VRF to generate a random number.

Smart contracts deployed on Sepolia testnet: 0x097d039Bb7353B0bcD3d585B5a71e8B575F2f3f7

Try it yourself: coinflip-double-up-your-eth.netlify.app/

Built With

• 
• 
• 
• 
• 

Getting Started

Prerequisites

Make sure you have the following ready:

• node.js installed (developed on LTS v20.12.0)
• yarn installed
• hardhat installed
• MetaMask installed in your browser

Then create a new repo, open your favorite code editor, and clone the repo with the following cmd:

git clone https://github.com/Pedrojok01/CoinFlip_2.0 .

Smart-Contracts Deployment

Install the dependencies

In your terminal, make sure you are in the COINFLIP_2.0 repo, then move to the blockchain folder :

cd blockchain

Then run the following command to install the dependencies:

yarn install

Deployement

To deploy your smart-contracts:

• Subscribe to Chainlink VRF v2.5 on the Chainlink VRF Sepolia dashboard. You can get some test LINK there: LINK Faucet.
• Add your subscription id to the deployment script in blockchain/scripts/deploy.js. To deploy on different chains, you will also have to adjust the COORDINATOR and KEY_HASH values. You can refer to the Chainlink docs to get the data for the desired network (if supported).
• Also, make sure that the network is configured in hardhat.config.js and that you have defined the required variables in the .env file.
• Edit the script in blockchain/package.json to deploy the contract on the network of your choice.
• Finally, run the command below to deploy to the network of your choice.

yarn deploy

Coverage

To check the coverage of the tests, run the following command:

yarn cover

And see the results printed in the terminal:

Static Analyzer

For basic security checks, you can run both Slither and Aderyn (refer to their doc to install them) with the following commands:

yarn slither

yarn aderyn

Aderyn will print a nice report file called report.md at the root of the project.

Config & Client

Before each deployment, make sure to:

• Replace the contract address in src/data/constants.js
• Replace the abi file in src/data/coinFlipAbi.js
• Make sure to fund the contract with some ETH ( Faucet for the Sepolia network )

---

• Change the COINFLIP_ADDRESS in /src/constants.js to your deployed contracts address;
• Copy the new abi file into the src/abis folder if you've made any changes to the contracts;
• Enable/disable, and update the suitable networks in truffle-config.js;
• In the blockchain/ repo, create a file called .secret and paste your mnemonic seed phrase inside; (Make sure you add this file in your .gitignore!!!)

Acknowledgments

• Img Shields
• Font Awesome
• Jazzicon

Use

You are now set to start your local server. Make sure you're still in COINFLIP 2.0 and type: yarn start

# Enjoy!!!

⭐️ ... and don't forget to leave a star if you like it! ⭐️

(back to top)