--- title: Adding more tests _Follow along with this video:_ --- ### Expanding our test coverage Welcome back! Let's continue testing our `Raffle` contract. We should test if the check upkeep returns false if the contract has no balance. Open your `RaffleTest.t.sol` and write the following: ```solidity function testCheckUpkeepReturnsFalseIfItHasNoBalance() public { // Arrange vm.warp(block.timestamp + interval + 1); vm.roll(block.number + 1); // Act (bool upkeepNeeded, ) = raffle.checkUpkeep(""); // Assert assert(!upkeepNeeded); } ``` We use `warp` and `roll` to set the `block.timestamp` in the future. We call `checkUpkeep` and record its return in memory. We check it returned `false`. **Note:** `!upkeepNeeded` means `not upkeepNeeded` meaning if `upkeepNeeded` is `false` that expression would read `not false` and `not false` is `true`. Run the test using `forge test --mt testCheckUpkeepReturnsFalseIfItHasNoBalance`. It passes, amazing! What else? We should test if the check upkeep function returns false if the raffle is not Open. Paste the following inside `RaffleTest.t.sol`: ```solidity function testCheckUpkeepReturnsFalseIfRaffleIsntOpen() public { // Arrange vm.prank(PLAYER); raffle.enterRaffle{value: entranceFee}(); vm.warp(block.timestamp + interval + 1); vm.roll(block.number + 1); raffle.performUpkeep(""); Raffle.RaffleState raffleState = raffle.getRaffleState(); // Act (bool upkeepNeeded, ) = raffle.checkUpkeep(""); // Assert assert(raffleState == Raffle.RaffleState.CALCULATING); assert(upkeepNeeded == false); } ``` We start by pranking the `PLAYER`. Then we enter the `raffle` using the correct `entranceFee`. After that, we use `warp` and `roll` to set `block.timestamp` in the future. We call `performUpkeep`. This will modify the `RaffleState` into `CALCULATING`. We then call `checkUpkeep` and record its return in memory. We check it returned `false`. We also check that the `RaffleState` is indeed `CALCULATING`. Run the test using: `forge test --mt testCheckUpkeepReturnsFalseIfRaffleIsntOpen`. It passes, great! So testing goes amazing, but how do we know what's left to test? Let's run the following command in the CLI: `forge coverage --report debug > coverage.txt` We are interested in the `Raffle.sol` file for now. You can search for that and see an output like this: ``` Uncovered for src/Raffle.sol: - Function "" (location: source ID 37, line 53, chars 1729-2253, hits: 0) - Line (location: source ID 37, line 54, chars 1913-1940, hits: 0) - Statement (location: source ID 37, line 54, chars 1913-1940, hits: 0) - Line (location: source ID 37, line 55, chars 1950-1971, hits: 0) - Statement (location: source ID 37, line 55, chars 1950-1971, hits: 0) - Line (location: source ID 37, line 56, chars 1981-2014, hits: 0) - Statement (location: source ID 37, line 56, chars 1981-2014, hits: 0) - Line (location: source ID 37, line 57, chars 2024-2056, hits: 0) - Statement (location: source ID 37, line 57, chars 2024-2056, hits: 0) - Line (location: source ID 37, line 59, chars 2067-2127, hits: 0) - Statement (location: source ID 37, line 59, chars 2067-2127, hits: 0) - Line (location: source ID 37, line 60, chars 2137-2156, hits: 0) - Statement (location: source ID 37, line 60, chars 2137-2156, hits: 0) - Line (location: source ID 37, line 61, chars 2166-2199, hits: 0) - Statement (location: source ID 37, line 61, chars 2166-2199, hits: 0) - Line (location: source ID 37, line 62, chars 2209-2246, hits: 0) - Statement (location: source ID 37, line 62, chars 2209-2246, hits: 0) - Branch (branch: 2, path: 0) (location: source ID 37, line 97, chars 3717-3918, hits: 0) - Branch (branch: 2, path: 1) (location: source ID 37, line 97, chars 3717-3918, hits: 0) - Line (location: source ID 37, line 98, chars 3750-3907, hits: 0) [...] ``` You can follow the locations indicated to find the lines not covered by tests. For example, in my `Raffle.sol` the code block starting on line 97 is this: ```solidity function performUpkeep(bytes calldata /* performData */) external override { (bool upkeepNeeded, ) = checkUpkeep(""); // require(upkeepNeeded, "Upkeep not needed"); @> if (!upkeepNeeded) { @> revert Raffle__UpkeepNotNeeded( @> address(this).balance, @> s_players.length, @> uint256(s_raffleState) @> ); } ``` And the output is right, we never tested this `if + revert` block inside `performUpkeep`. But beware! This is not entirely accurate. For example, `checkUpkeep` doesn't appear in the report anymore, but we didn't test every single line out of it. We never tested if the upkeep returns false if enough time hasn't passed, we also never checked if the upkeep returns true when everything is alright. Try writing these two tests yourself and then compare them against what [Patrick wrote](https://github.com/Cyfrin/foundry-smart-contract-lottery-f23/blob/d106fe245e0e44239dae2479b63545351ed1236a/test/unit/RaffleTest.t.sol). Great job! Let's keep going!