This is a section of the Cyfrin Foundry Solidity Course.

DSCEngine Example Decentralized Stablecoin Example

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.

On this project we work more tests and tackle fuzzing, invariants and slither.

• Foundry DeFi Stablecoin
• About
• Getting Started
  • Requirements
  • Quickstart
• Updates
• Usage
  • Start a local node
  • Deploy
  • Deploy - Other Network
  • Testing
    • Test Coverage
• Deployment to a testnet or mainnet
  • Scripts
  • Estimate gas
• Formatting
• Slither
• Thank you!

• 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)

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

make anvil

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

make deploy

See below

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

forge coverage

and for coverage based testing:

forge coverage --report debug

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.
  • You can learn how to export it here.
• SEPOLIA_RPC_URL: This is url of the sepolia 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 testnet ETH. You should see the ETH show up in your metamask.

2. Deploy

make deploy ARGS="--network sepolia"

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

2. Approve the WETH

cast send 0xdd13E55209Fd76AfE204dBda4007C227904f0a81 "approve(address,uint256)" 0x091EA0838eBD5b7ddA2F2A641B068d6D59639b98 1000000000000000000 --rpc-url $SEPOLIA_RPC_URL --private-key $PRIVATE_KEY

3. Deposit and Mint DSC

cast send 0x091EA0838eBD5b7ddA2F2A641B068d6D59639b98 "depositCollateralAndMintDsc(address,uint256,uint256)" 0xdd13E55209Fd76AfE204dBda4007C227904f0a81 100000000000000000 10000000000000000 --rpc-url $SEPOLIA_RPC_URL --private-key $PRIVATE_KEY

You can estimate how much gas things cost by running:

forge snapshot

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

To run code formatting:

forge fmt

slither :; slither . --config-file slither.config.json