--- title: Tests and deploy the lottery smart contract pt.1 _Follow along with this video:_ --- ### Next steps Great! We've written some amazing code, but you know our job here is not done! We need to test it. Let's be smart about testing, what do we need to be able to properly test the contract and what kind of tests shall we do? **Plan:** 1. Write deploy scripts 2. Write tests 1. Local chain 2. Forked Testnet 3. Forked Mainnet 3. Maybe deploy and run on Sepolia? ### Deployment scripts Please create a new file called `DeployRaffle.s.sol` inside the `script` folder. And now you know the drill, go write as much of it as you can! After you get stuck or after you finish come back and check it against the version below: ```solidity // SPDX-License-Identifier: MIT pragma solidity ^0.8.19; import {Script} from "forge-std/Script.sol"; import {Raffle} from "../src/Raffle.sol"; contract DeployRaffle is Script { function run() external returns (Raffle) { } } ``` We've started with the traditional `SPDX` declaration, then specified the `pragma solidity` version. We imported the `Script` from Foundry and the `Raffle` contract because we want to do a Raffle deployment script, declared the contract's name and made it inherit `Script` and created the `run` function which will return our `Raffle` contract deployment. Great! Let's work smart, looking again over the plan we see that we'll have to deploy the Raffle contract on at least 3 different chains. Let's stop here with the deployment script and work on the `HelperConfig`. Create a new file called `HelperConfig.s.sol` in the `script` folder. Inside let's create the `HelperConfig` contract: ```solidity // SPDX-License-Identifier: MIT pragma solidity ^0.8.19; import {Script} from "forge-std/Script.sol"; contract HelperConfig is Script { struct NetworkConfig { uint256 entranceFee; uint256 interval; address vrfCoordinator; bytes32 gasLane; uint64 subscriptionId; uint32 callbackGasLimit; } } ``` We start with the `SPDX `and `pragma solidity` declarations. Then, we import `Script` from Foundry, name the contract and make it inherit `Script`. Cool! Now what do we need to deploy the `Raffle` contract? That information can be easily found in the `Raffle` contract's constructor: `constructor(uint256 entranceFee, uint256 interval, address vrfCoordinator, bytes32 gasLane, uint64 subscriptionId, uint32 callbackGasLimit)` We created a new struct called `NetworkConfig` and we matched its contents with the Raffle's constructor input. Great! Now let's design a function that returns the proper config for Sepolia: ```solidity function getSepoliaEthConfig() public pure returns (NetworkConfig memory) { return NetworkConfig({ entranceFee: 0.01 ether, interval: 30, // 30 seconds vrfCoordinator: 0x9DdfaCa8183c41ad55329BdeeD9F6A8d53168B1B, gasLane: 0x787d74caea10b2b357790d5b5247c2f63d1d91572a9846f780606e4d953677ae, subscriptionId: 0, // If left as 0, our scripts will create one! callbackGasLimit: 500000, // 500,000 gas }); } ``` The function above returns a `NetworkConfig` struct with data taken from [here](https://docs.chain.link/vrf/v2-5/supported-networks#sepolia-testnet). The `interval`, `entranceFee` and `callbackGasLimit` were selected by Patrick. Ok, we need a couple more things. We need a constructor that checks what blockchain we are on and attributes a state variable, let's call it `activeNetworkConfig`, the proper config for the chain used. ```solidity NetworkConfig public activeNetworkConfig; constructor() { if (block.chainid == 11155111) { activeNetworkConfig = getSepoliaEthConfig(); } else { activeNetworkConfig = getOrCreateAnvilEthConfig(); } } ``` Good, we only missing the `getOrCreateAnvilEthConfig` function. For now, let's create only a part of it: ```solidity function getOrCreateAnvilEthConfig() public returns (NetworkConfig memory anvilNetworkConfig) { // Check to see if we set an active network config if (activeNetworkConfig.vrfCoordinator != address(0)) { return activeNetworkConfig; } } ``` We check if the `activeNetworkConfig` is populated, and if is we return it. If not we need to deploy some mocks. But more on that in the next lesson.