Foundry Fund Me

This is a section of the Cyfrin Solidity Course.

⭐️ Updraft | Foundry Fund Me

• Foundry Fund Me
• Getting Started
  • Requirements
  • Quickstart
    • Optional Gitpod
• Usage
  • Deploy
  • Testing
    • Test Coverage
  • Local zkSync
    • (Additional) Requirements
    • Setup local zkSync node
    • Deploy to local zkSync node
• Deployment to a testnet or mainnet
  • Scripts
    • Withdraw
  • Estimate gas
• Formatting
• Additional Info:
  • Let's talk about what "Official" means
  • Summary
• Thank you!

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-fund-me-cu
cd foundry-fund-me-cu
make

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.

Usage

Deploy

forge script script/DeployFundMe.s.sol

Testing

We talk about 4 test tiers in the video.

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

This repo we cover #1 and #3.

forge test

or

// Only run test functions matching the specified regex pattern.

"forge test -m testFunctionName" is deprecated. Please use 

forge test --match-test testFunctionName

or

forge test --fork-url $SEPOLIA_RPC_URL

Test Coverage

forge coverage

Local zkSync

The instructions here will allow you to work with this repo on zkSync.

(Additional) Requirements

In addition to the requirements above, you'll need:

• foundry-zksync
  • You'll know you did it right if you can run forge --version and you see a response like forge 0.0.2 (816e00b 2023-03-16T00:05:26.396218Z).
• npx & npm
  • You'll know you did it right if you can run npm --version and you see a response like 7.24.0 and npx --version and you see a response like 8.1.0.
• docker
  • You'll know you did it right if you can run docker --version and you see a response like Docker version 20.10.7, build f0df350.
  • Then, you'll want the daemon running, you'll know it's running if you can run docker --info and in the output you'll see something like the following to know it's running:

Client:
 Context:    default
 Debug Mode: false

Setup local zkSync node

Run the following:

npx zksync-cli dev config

And select: In memory node and do not select any additional modules.

Then run:

npx zksync-cli dev start

And you'll get an output like:

In memory node started v0.1.0-alpha.22:
 - zkSync Node (L2):
  - Chain ID: 260
  - RPC URL: http://127.0.0.1:8011
  - Rich accounts: https://era.zksync.io/docs/tools/testing/era-test-node.html#use-pre-configured-rich-wallets

Deploy to local zkSync node

make deploy-zk

This will deploy a mock price feed and a fund me contract to the zkSync node.

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.
  • 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.

2. Get testnet ETH

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

3. Deploy

forge script script/DeployFundMe.s.sol --rpc-url $SEPOLIA_RPC_URL --private-key $PRIVATE_KEY --broadcast --verify --etherscan-api-key $ETHERSCAN_API_KEY

Scripts

After deploying to a testnet or local net, you can run the scripts.

Using cast deployed locally example:

cast send <FUNDME_CONTRACT_ADDRESS> "fund()" --value 0.1ether --private-key <PRIVATE_KEY>

or

forge script script/Interactions.s.sol:FundFundMe --rpc-url sepolia  --private-key $PRIVATE_KEY  --broadcast
forge script script/Interactions.s.sol:WithdrawFundMe --rpc-url sepolia  --private-key $PRIVATE_KEY  --broadcast

Withdraw

cast send <FUNDME_CONTRACT_ADDRESS> "withdraw()"  --private-key <PRIVATE_KEY>

Estimate gas

You can estimate how much gas things cost by running:

forge snapshot

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

Formatting

To run code formatting:

forge fmt

Additional Info:

Some users were having a confusion that whether Chainlink-brownie-contracts is an official Chainlink repository or not. Here is the info. Chainlink-brownie-contracts is an official repo. The repository is owned and maintained by the chainlink team for this very purpose, and gets releases from the proper chainlink release process. You can see it's still the smartcontractkit org as well.

https://github.com/smartcontractkit/chainlink-brownie-contracts

Let's talk about what "Official" means

The "official" release process is that chainlink deploys it's packages to npm. So technically, even downloading directly from smartcontractkit/chainlink is wrong, because it could be using unreleased code.

So, then you have two options:

1. Download from NPM and have your codebase have dependencies foreign to foundry
2. Download from the chainlink-brownie-contracts repo which already downloads from npm and then packages it nicely for you to use in foundry.

Summary

1. That is an official repo maintained by the same org
2. It downloads from the official release cycle chainlink/contracts use (npm) and packages it nicely for digestion from foundry.

Thank you!