foundry-fundamentals

Installation:

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

Then: (can also be used to update foundry)

foundryup

Create a new project

forge init

Help

forge help

Compile Contract

forge compile

Run Local Eth instance

anvil

Deploy Contract

forge create

with rpc url

forge create --rpc-url

Deploy Using a Script

Example deploy script:

// SPDX-License-Identifier: MIT
pragma solidity 0.8.19;

import "forge-std/Script.sol";
import "../src/SimpleStorage.sol";

contract DeploySimpleStorage is Script {
    function run() external returns (SimpleStorage) {
        vm.startBroadcast();
        SimpleStorage simpleStorage = new SimpleStorage();
        vm.stopBroadcast();
        return simpleStorage;
    }
}

Run:

forge script /path --rpc-url --broadcast --private-key

Use Cast to convert from hex to dec

cast --to-base 0x714e1 dec

Use Cast to encrypt private key

cast wallet import defaultKey --interactive

where defaultKey is the name of the account

Deploy using encrypted private key and script

forge script /path --rpc-url [url] --account defaultKey --sender [address of defaultKey] --broadcast

List wallet list

cast wallet list

Interact with a Contract using the CLI

Send Transaction

cast send [to] [function] "store(uint256)" [params] 25 --private-key --rpc-url

Call (Read)

cast call [to] [function] "retrieve()"

Install Dependencies

forge install [package_name]

Format Code with Forge

forge fmt

Test

forge test

for different level of visisbility use -v/ -vv/ -vvv (see stack traces)

Run a single function unit test

forge test --match-test [function_name]

Run a Forked test

Test the code on a simulated real environment:

forge test --fork-url [rpc-url]

Check coverage of tests

forge coverage

Get Full Coverage Report

forge coverage --report debug > coverage.txt

Check Gas Consumption of Tests

forge snapshot

Useful Stuff for Testing

Create a new random address

address(i)

Create a new account

address USER = makeAddr("user");

Give an initial balance to the new account

uint256 USER_STARTING_BALANCE = 100 ether;
vm.deal(USER, USER_STARTING_BALANCE);

Set msg.sender of next transaction

vm.prank(USER)

Set msg.sender + fund account

hoax(USER, 100 ether)

Set Gas Price for Next Transaction

vm.taxGasPrice(WEI)

Test Reverts

 vm.expectRevert(Contract.errorName.selector);
 contract.functionThatShouldRevert();

Test Reverts with args

vm.expectRevert(abi.encodeWithSelector(Contract.errorName.selector, args1, args2);
contract.functionThatShouldRevert();

Test Emit Event

Use vm.expectEmit()

vm.expectEmit(trueIfTopic1Exists, trueIfTopic2Exists, trueIfTopic3Exists, trueIfNonIndexedDataExists, contractAddressThatWillEmitEvent)
emit event(params)

topics are the indexed params in the event

for example, here we only have topic1:

event RaffleEntered(address indexed player);

it would look like this:

vm.expectEmit(true, false, false, false, address(raffle)
emit RaffleEntered(PLAYER);

Note: Events need to be added at the top of the test file.

Change block.timestamp

vm.warp(timestamp)

Change block.number

vm.roll(number)

Get Recorded Logs

vm.recordLogs();
contract.function();
Vm.Log[] memory entries = vm.getRecordedLogs();

Advanced Debugging

forge test --debug testFunctionName

Check Storage Layout of Contract

forge inspect [CONTRACT_NAME] storageLayout

Using Cast to Get Value at Storage Slot

cast storage [CONTRACT_ADDRESS] [SLOT_NUMBER]

Use Cast to get function selector

cast sig "[FUNCTION_NAME]()"

Chisel

chisel

Chisel can be used to write Solidity directly in the terminal to quicly test logic.

Bonus

Headers

Generate headers using this tool: https://github.com/transmissions11/headers

headers [name]

Extra

For extra information, cyfrin foundry github link.