_Follow along the course with this video._ --- ### UUPS Tests In this lesson we're going to be writing our test suite which will enable us to really demonstrate how this upgradeability works in practice. Begin by creating the file `test/DeployAndUpgradeTest.t.sol`. We know the drill in setting this up by now! ```solidity // SPDX-License-Identifier: MIT pragma solidity ^0.8.18; import {Test} from "forge-std/Test.sol"; import {DeployBox} from "../script/DeployBox.s.sol"; import {UpgradeBox} from "../script/UpgradeBox.s.sol"; import {BoxV1} from "../src/BoxV1.sol"; import {BoxV2} from "../src/BoxV2.sol"; contract DeployAndUpgradeTest is Test { DeployBox public deployer; UpgradeBox public upgrader; address public OWNER = makeAddr("owner"); address public proxy; function setUp(){ deployer = new DeployBox(); upgrader = new UpgradeBox(); proxy = deployer.run(); // currently points to BoxV1 } } ``` This is a little more than boilerplate, but I trust your skills to be improving as we continue, so walking through each step granularly shouldn't be as necessary. In the above, we're simply importing many of the contracts we expect to be working with in our tests and then declaring and deploying them within our setUp function. Now we can write our test, we'll need to deploy BoxV2. ```solidity function testUpgrades() public { BoxV2 box2 = new BoxV2(); upgrader.upgradeBox(proxy, address(box2)); } ``` Recall what our upgradeBox function is going within UpgradeBox.s.sol: ```solidity function upgradeBox(address proxyAddress, address newBox) public returns (address) { vm.startBroadcast(); BoxV1 proxy = BoxV1(proxyAddress); proxy.upgradeTo(address(newBox)); vm.stopBroadcast(); return address(proxy); } ``` This function is taking the proxy address and our new implementation address as parameters and calling the upgradeTo function. Now, in our test, we can set an expected value and compare it against what version a call to the `version` function on our proxy will return. ```solidity function testUpgrades() public { BoxV2 box2 = new BoxV2(); upgrader.upgradeBox(proxy, address(box2)); uint256 expectedValue = 2; assertEq(expectedValue, BoxV2(proxy).version()); } ``` It's best practice to split tests up as best one can, but let's check more here while we're at it. We added new function to BoxV2, let's ensure they work after our upgrade. ```solidity function testUpgrades() public { BoxV2 box2 = new BoxV2(); upgrader.upgradeBox(proxy, address(box2)); uint256 expectedValue = 2; assertEq(expectedValue, BoxV2(proxy).version()); BoxV2(proxy).setNumber(7); assertEq(7, BoxV2(proxy).getNumber()); } ``` You know what, I changed my mind, let's add one more simple test to verify the implementation we begin with. ```solidity function testProxyStartAsBoxV1() public { vm.expectRevert(); BoxV2(proxy).setNumber(7); } ``` We would expect the above to revert because BoxV1, on deployment, doesn't contain a setNumber function! Let's test these one at a time. ```bash forge test --mt testProxyStartAsBoxV1 ``` We would expect this to pass if it reverts. ::image{src='/foundry-upgrades/7-uups-tests/uups-tests1.png' style='width: 100%; height: auto;'} Looks great! Our BoxV1 doesn't have the setNumber function. Now we can try our other test! ```bash forge test --mt testUpgrades ``` ::image{src='/foundry-upgrades/7-uups-tests/uups-tests1.png' style='width: 100%; height: auto;'} ### Wrap Up Boom! We've successfully upgraded our upgradeable Box Protocol. I've included additional tests for this within the [**GitHub Repo**](https://github.com/Cyfrin/foundry-upgrades-f23) for this section, so don't hesitate to try and write your own and compare what you come up with versus the repo! In this section we'll be walking through one big example test, but I encourage you to try to write more, as always.