_Follow along with this video:_ --- ### Expanding our test coverage Welcome back! Let's continue testing our `Raffle` contract. We should test if the Raffle reverts when you don't pay enough money. Open your `RaffleTest.t.sol` and write the following: ```solidity function testRaffleRevertsWhenYouDontPayEnough() public { // Arrange vm.prank(PLAYER); // Act / Accert vm.expectRevert(Raffle.Raffle__NotEnoughEthSent.selector); raffle.enterRaffle(); } ``` We use `vm.prank(PLAYER);` to mimic our user and to test the revert functionality we use `vm.expectRevert();`. When we go back to Raffle.sol we can see that the error we should get is `Raffle__NotEnoughEthSent`. This we can leverage in our `expectRevert()` function: `vm.expectRevert(Raffle.Raffle__NotEnoughEthSent.selector);`. Like this, we say, we expect a revert due to the `Raffle__NotEnoughEthSent` error. We will teach you about the selector key and what functions selectors are later in detail. To test run: `forge test --mt testRaffleRevertsWhenYouDontPayEnough` It passes! Great! Besides, we want to test if the Raffle updates or more precisely adds players to the `s_players` array in `Raffle.sol` ```solidity function testRaffleRecordsPlayersWhenTheyEnter() public { // Arrange vm.prank(PLAYER); // Act raffle.enterRaffle{value: entranceFee}(); // Assert address playerRecorded = raffle.getPlayer(0); assert(playerRecorded == PLAYER); } ``` With `vm.prank(PLAYER);` we pretend to be a player and enter the Raffle `raffle.enterRaffle{value: entranceFee}();` with an entrance fee. Unfortunately, we don't have yet a function to get the players from `Raffle.sol`. So let's do this! Go to `Raffle.sol` and add the following function to your getter functions: ```solidity function getPlayer(uint256 indexOfPlayer) external view returns (address) { return s_players[indexOfPlayer]; } ``` Then let's use this function in our test. Since, we only have one user we want to get the first player: `address playerRecorded = raffle.getPlayer(0);` Run the test using `forge test --mt testRaffleRecordsPlayersWhenTheyEnter`. Ohhh, it fails. Let's test again with more verbose: `forge test --mt testRaffleRecordsPlayersWhenTheyEnter -vvvv` Ahhh, we are **OutOfFunds**. Thus, let's add some funds in the `setup()` function: `vm.deal(PLAYER, STARTING_PLAYER_BALANCE);` ```solidity function setUp() external { DeployRaffle deployer = new DeployRaffle(); (raffle, helperConfig) = deployer.deployContract(); HelperConfig.NetworkConfig memory config = helperConfig.getConfig(); entranceFee = config.entranceFee; interval = config.interval; vrfCoordinator = config.vrfCoordinator; gasLane = config.gasLane; callbackGasLimit = config.callbackGasLimit; subscriptionId = config.subscriptionId; vm.deal(PLAYER, STARTING_PLAYER_BALANCE); } ``` Let's test once more: `forge test --mt testRaffleRecordsPlayersWhenTheyEnter -vvvv` It passes, amazing! Great job! Let's keep going!