hello-foundry

https://github.com/foundry-rs/foundry

https://book.getfoundry.sh/

Basic

• Install

$ curl -L https://foundry.paradigm.xyz | bash
$ foundryup

• Init

$ forge init

• Basic commands

$ forge build
$ forge test
$ forge test --match-path test/HelloWorld -vvvv

---

• Test
  • counter app
  • test setup, ok, fail
  • match
  • verbose
  • gas report

$ forge test --match-path test/Counter.t.sol -vvv --gas-report

---

• Solidity version and optimizer settings

https://github.com/foundry-rs/foundry/tree/master/config

---

• Remapping

$ forge install transmissions11/solmate
$ forge update lib/solmate
$ forge remove solmate

$ forge install OpenZeppelin/openzeppelin-contracts

$ forge remappings
@openzeppelin/contracts/=lib/openzeppelin-contracts/contracts/
ds-test/=lib/solmate/lib/ds-test/src/
erc4626-tests/=lib/openzeppelin-contracts/lib/erc4626-tests/
forge-std/=lib/forge-std/src/
openzeppelin-contracts/=lib/openzeppelin-contracts/

If you got a error underline in vscode, please use below command and reopen vscode editor.

$ forge remappings > remappings.txt

---

• Formatter

$ forge fmt

---

• console (Counter, test, log int)

forge test --match-path test/Console.t.sol -vv

---

Intermediate

---

• Test auth --> $ forge test -vvvv --match-path test/Auth.t.sol
• Test error --> $ forge test -vvvv --match-path test/Error.t.sol
  • vm.expectRevert
  • require error message
  • custom error
  • error label assertions
• Test event (expectEmit)
  • forge test --match-path test/Event.t.sol -vvvv
• Test time (Auction.sol)
  • forge test --match-path test/Time.t.sol -vvvv
• Test send eth (Wallet.sol) - hoax, deal
  • forge test --match-path test/Wallet.t.sol -vvvv
• Test signature
  • forge test --match-path test/Signature.t.sol -vvvv
  • forge test --match-path test/app/GaslessTokenTransfer.t.sol -vvv

Advanced

• mainnet fork

$ forge test --fork-url $FORK_URL --match-path test/Fork.t.sol -vvv

• main fork deal (DAI)

$ forge test --fork-url $FORK_URL --match-path test/DAI.t.sol -vvv

• crosschain fork

• Fuzzing (assume, bound)

$ forge test --match-path test/Fuzz.t.sol

• Invariant

# Open testing
$ forge test --match-path test/invariants/Invariant_0.t.sol -vvv
$ forge test --match-path test/invariants/Invariant_1.t.sol -vvv
# Handler
$ forge test --match-path test/invariants/Invariant_2.t.sol -vvv
# Actor management
$ forge test --match-path test/invariants/Invariant_3.t.sol -vvv

• FFI

$ forge test --match-path test/FFI.t.sol --ffi -vvv

• Differential testing

# virtual env
$ python3 -m pip install --user virtualenv
$ virtualenv -p python3 venv
$ source venv/bin/activate

$ pip install eth-abi

$ FOUNDRY_FUZZ_RUNS=100 forge test --match-path test/DifferentialTest.t.sol --ffi -vvv

Misc

• Vyper

https://github.com/0xKitsune/Foundry-Vyper

0. Install vyper

# virtual env
$ python3 -m pip install --user virtualenv
$ virtualenv -p python3 venv
$ source venv/bin/activate

$ pip3 install vyper==0.3.7

# Check installation
$ vyper --version

1. Put Vyper contract inside vyper_contracts
2. Declare Solidity interface inside src
3. Copy & paste lib/utils/VyperDeployer.sol
4. Write test

$ forge test --match-path test/Vyper.t.sol --ffi

• ignore error code

ignored_error_codes = ["license", "unused-param", "unused-var"]

• Deploy

$ source .env

$ forge script script/Token.s.sol:TokenScript --rpc-url $SEPOLIA_RPC_URL --broadcast --etherscan-api-key $ETHERSCAN_API_KEY --verify -vvvv

• Inspect

forge-inspect - Get specialized information about a smart contract

https://book.getfoundry.sh/reference/forge/forge-inspect?highlight=forge%20inspect#forge-inspect

• Cast example

https://book.getfoundry.sh/cast/

Import, list and remove wallet

# Import private key
ACCOUNT=burner
cast wallet import $ACCOUNT --private-key PRIVATE_KEY

# List wallets
cast wallet list

# Wallet saved to ~/.foundry/keystores
ls ~/.foundry/keystores/

# Remove wallet
rm -rf ~/.foundry/keystores/$ACCOUNT

Send transaction and query contract

$ DST=0x3aaee3149aCFD9d0e536CA7C1526cB010fa88Cdd
$ FUNC_SIG="set(uint256)"
$ ARGS="777"
$ RPC=https://eth-goerli.g.alchemy.com/v2/y-OzRlSG33yMwy4IfvVD3WlUByo0K0Lq

# Send tx
$ cast send --account $ACCOUNT --rpc-url $RPC $DST $FUNC_SIG $ARGS

# Query smart contract
$ cast call --rpc-url $RPC $DST "val()(uint256)"

• Forge geiger

forge-geiger - Detects usage of unsafe cheat codes in a foundry project and its dependencies.

$ forge geiger