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Hardhat | Celo Composer

This project demonstrates a basic Hardhat use case. It comes with a sample contract, a test for that contract, a sample script that deploys that contract, and an example of a task implementation, which simply lists the available accounts.

Setup & Intallation​

Alfajores Testnet Setup​

Note This setup is not required when using a local development blockchain (like celo-devchain or Ganache).

  1. Create a .env file similar to .envexample.
  2. Paste the private key in .env.
  3. Faucet your account with the Alfajores testnet faucet here.

Develop​

  1. Write your contracts in ./contracts.
  2. Update contract deployment scripts in ./deploy.
  3. Deploy contracts with yarn hardhat-deply from the root directory. Optionally add the reset flag (yarn hardhat-deploy --reset) to overwrite previous deployment info. The default deployment network is specified in hardhat.config.js and is set to alfajores initially. You can also overwrite previous deployments and redeploy when there are changes to the deployment script or contracts automatically by running yarn deploy-reset-watch. You can specify a specific network deployment directly with
npx hardhat-deploy deploy --network [network name]

Network configs are defined in hardhat.config.js.

Celo devchain​

Run a local development Celo chain with yarn devchain in the packages/hardhat folder. You can print the addresses of the Celo protocol contracts with npx @terminal-fi/celo-devchain --test.

This is a version of Ganache (@celo/ganache-cli) that deploys the Celo core protocol contracts when it starts.

NOTE: @celo/ganache-cli works only with Node 10 or Node 12 versions. Using Node 14 or later will result in errors.

NOTE: @celo/ganache-cli currently doesn't support locally signed transactions. If you send a locally signed transaction it will throw: Error: Number can only safely store up to 53 bits error and crash. Thus you have to make sure your ContractKit doesn't actually have the private keys for test addresses and send transactions to be signed by ganache-cli itself.

Start​

npx celo-devchain --port 8545

or

yarn devchain

Generate Typescript bindings​

This setting defaults to the web3 v1 bindings because that is what is used by use-contractkit in packages/react-app.

You can change the output directory and target in hardhat.config.js.

npx hardhat typechain

Read more about Typechain here and more about the hardhat plugin here.

Run sanity tests and print all core contract addresses​

npx @terminal-fi/celo-devchain --test

Fork mainnet with Ganache​

You can get a local copy of mainnet by forking with Ganache. Learn more about forking mainnet with Ganache here.

There is a script provided (yarn fork-mainnet) to fork mainnet and fund the same test accounts that come with Celo devchain. Sometimes sending transactions from the first account (which defaults to 0x5409ED021D9299bf6814279A6A1411A7e866A631) is delayed and sending test transactions from the other accounts works better for some reason. 🤷 The private keys of the associated test accounts are printed in account_keys.json.

Verify your contracts​

hardhat-celo​

You can easily verify your contracts deployed to the associated networks with hardhat-celo.

Reference

npx hardhat verify smart-contract-address parameter(s) --network alfajores

On Mainnet:

npx hardhat verify smart-contract-address parameter(s) --network celo

Sourcify​

Additionally, you can easily verify your contracts deployed to the associated networks with the following commands.

Reference

On Alfajores:

npx hardhat --network alfajores sourcify

On Mainnet:

npx hardhat --network celo sourcify

Deploy with Figment Datahub​

Figment Datahub provides RPC & REST APIs for Celo network. To learn more about Datahub refer this doc - https://docs.figment.io/introduction/what-is-datahub. Follow these steps to deploy your smart contract with Figment datahub's RPC.

  • Create account on Datahub.
  • On the dashboard, click on Create new app and select Celo from the protocol list.
  • Once you have created an app, copy the api key.
  • Edit hardhat.config.js and update alfajoresDatahub and celoDatahub with the API Key.
  • Run the test or deploy the contract with following commands.
npx hardhat run scripts/run.ts --network alfajoresDatahub

npx hardhat run scripts/deploy.ts --network celoDatahub