/solidity-crowdfunding-smartcontract

Developing, testing and deploying solidity smartcontracts with HardHat framework

Primary LanguageJavaScript

Developing basic Solidity CrowdFunding SmartContract using hardhat framework

Getting Started

Requirements

  • git
    • You'll know you did it right if you can run git --version and you see a response like git version x.x.x
  • Nodejs
    • You'll know you've installed nodejs right if you can run:
      • node --version and get an ouput like: vx.x.x
  • Yarn instead of npm
    • You'll know you've installed yarn right if you can run:
      • yarn --version and get an output like: x.x.x
      • You might need to install it with npm or corepack

Testing

yarn hardhat test

Test Coverage

yarn hardhat coverage

Deploy to hardhat local network

yarn hardhat deploy

This command will deploy FundMe.sol and the MockV3Aggregator.sol. This is because the V3Aggregator contract doesn't exist in our local networkd thus we need to deploy a mocked version of it.

Deployment to a testnet or mainnet

  1. Setup environment variabltes

You'll want to set your RINKEBY_RPC_URL and PRIVATE_KEY as environment variables. You can add them to a .env file, similar to what you see in .env.template.

  • PRIVATE_KEY: The private key of your account (like from metamask). NOTE: FOR DEVELOPMENT, PLEASE USE A KEY THAT DOESN'T HAVE ANY REAL FUNDS ASSOCIATED WITH IT.
  • RINKEBY_RPC_URL: This is url of the rinkeby testnet node you're working with. You can get setup with one for free from Alchemy
  1. Get testnet ETH

Head over to faucets.chain.link and get some tesnet ETH. You should see the ETH show up in your metamask.

  1. Deploy
yarn hardhat deploy --network rinkeby

This command will only deploy FundMe.sol and will verify it in Etherscan. The V3Aggregator contract already exists on testnets and mainnets thus we don't need to deploy it, as explained in the comments in the ./01-deploy-fund-me.js file.

Estimate gas

You can estimate how much gas things cost by running:

yarn hardhat test

And you'll see and output file called gas-report.txt

Estimate gas cost in USD

To get a USD estimation of gas cost, you'll need a COINMARKETCAP_API_KEY environment variable. You can get one for free from CoinMarketCap.

Then, uncomment the line coinmarketcap: COINMARKETCAP_API_KEY, in hardhat.config.js to get the USD estimation. Just note, everytime you run your tests it will use an API call, so it might make sense to have using coinmarketcap disabled until you need it. You can disable it by just commenting the line back out.

Verify on etherscan

If you deploy to a testnet or mainnet, you can verify it if you get an API Key from Etherscan and set it as an environemnt variable named ETHERSCAN_API_KEY. You can pop it into your .env file as seen in the .env.example.

In it's current state, if you have your api key set, it will auto verify kovan contracts!

However, you can manual verify with:

yarn hardhat verify --constructor-args arguments.js DEPLOYED_CONTRACT_ADDRESS

Interact with contract

In order to call the fund() or withdraw() functions of a deployed contract you can run the ./scripts/fund.js or ./scripts/withdraw.js respectively.

yarn hardhat run ./scripts/fund.js

yarn hardhat run ./scripts/withdraw.js

If you want to interact with the contracts deployd on a Testnet, simply add the --network parameter to the command followed by the name of the network

yarn hardhat run ./scripts/fund.js --network rinkeby