Foundry DeFi Stablecoin

This is a section of the Cyfrin Foundry Solidity Course.

DSCEngine Example Decentralized Stablecoin Example

About

This project is meant to be a stablecoin where users can deposit WETH and WBTC in exchange for a token that will be pegged to the USD.

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
  • foundry
    • You'll know you did it right if you can run forge --version and you see a response like forge 0.2.0 (816e00b 2023-03-16T00:05:26.396218Z)

Quickstart

git clone https://github.com/Cyfrin/foundry-defi-stablecoin-f23
cd foundry-defi-stablecoin-f23
forge build

Optional Gitpod

If you can't or don't want to run and install locally, you can work with this repo in Gitpod. If you do this, you can skip the clone this repo part.

Open in Gitpod

Updates

  • The latest version of openzeppelin-contracts has changes in the ERC20Mock file. To follow along with the course, you need to install version 4.8.3 which can be done by forge install openzeppelin/openzeppelin-contracts@v4.8.3 --no-commit instead of forge install openzeppelin/openzeppelin-contracts --no-commit

Usage

Start a local node

make anvil

Deploy

This will default to your local node. You need to have it running in another terminal in order for it to deploy.

make deploy

Deploy - Other Network

See below

Testing

We talk about 4 test tiers in the video.

  1. Unit
  2. Integration
  3. Forked
  4. Staging

In this repo we cover #1 and Fuzzing.

forge test

Test Coverage

forge coverage

and for coverage based testing:

forge coverage --report debug

Deployment to a testnet or mainnet

  1. Setup environment variables

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

  • 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.
  • SEPOLIA_RPC_URL: This is url of the goerli testnet node you're working with. You can get setup with one for free from Alchemy

Optionally, add your ETHERSCAN_API_KEY if you want to verify your contract on Etherscan.

  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
make deploy ARGS="--network sepolia"

Scripts

Instead of scripts, we can directly use the cast command to interact with the contract.

For example, on Sepolia:

  1. Get some WETH
cast send 0xdd13E55209Fd76AfE204dBda4007C227904f0a81 "deposit()" --value 0.1ether --rpc-url $SEPOLIA_RPC_URL --private-key $PRIVATE_KEY
  1. Approve the WETH
cast send 0xdd13E55209Fd76AfE204dBda4007C227904f0a81 "approve(address,uint256)" 0x091EA0838eBD5b7ddA2F2A641B068d6D59639b98 1000000000000000000 --rpc-url $SEPOLIA_RPC_URL --private-key $PRIVATE_KEY
  1. Deposit and Mint DSC
cast send 0x091EA0838eBD5b7ddA2F2A641B068d6D59639b98 "depositCollateralAndMintDsc(address,uint256,uint256)" 0xdd13E55209Fd76AfE204dBda4007C227904f0a81 100000000000000000 10000000000000000 --rpc-url $SEPOLIA_RPC_URL --private-key $PRIVATE_KEY

Estimate gas

You can estimate how much gas things cost by running:

forge snapshot

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

Formatting

To run code formatting:

forge fmt

Thank you!

If you appreciated this, feel free to follow me or donate!

ETH/Arbitrum/Optimism/Polygon/etc Address: 0x9680201d9c93d65a3603d2088d125e955c73BD65

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