add fuzz test

.gitignore

@@ -12,3 +12,4 @@ docs/
 
 # Dotenv file
 .env
+.DS_Store

.vscode/settings.json

@@ -19,5 +19,6 @@
     "titleBar.inactiveForeground": "#15202b99"
   },
   "peacock.color": "#7db3df",
-  "editor.defaultFormatter": "JuanBlanco.solidity"
+  "solidity.packageDefaultDependenciesDirectory": "lib",
+  "solidity.packageDefaultDependenciesContractsDirectory": "src"
 }

foundry.toml

@@ -3,14 +3,14 @@ src = "src"
 out = "out"
 libs = ["lib"]
 
-[fuzz]
-runs = 4096
-
 ffi = true
 ast = true
 build_info = true
 extra_output = ["storageLayout"]
 solc = "0.8.24"
 remappings = ["forge-std/=lib/forge-std/src/"]
 
+[fuzz]
+runs = 4096
+
 # See more config options https://github.com/foundry-rs/foundry/blob/master/crates/config/README.md#all-options

test/fuzz/FuzzVotingPowerExchange.t.sol

@@ -136,6 +136,33 @@ contract VotingPwoerExchangeTest is Test {
         assertEq(govToken.balanceOf(participant2), exchangedVotingPower);
     }
 
+    function testExchangeWithAnyAmountWithinNewCapWillSucceed(uint256 amount) public {
+        // mint 75240 utility token to the participant2
+        vm.startPrank(minter);
+        utilityToken.mint(participant2, 92675 * 1e18);
+        vm.stopPrank();
+
+        // set the cap to 49e18
+        vm.prank(manager);
+        votingPowerExchange.setVotingPowerCap(110e18);
+        vm.stopPrank();
+        // start testing
+        amount = bound(amount, 1e18, 92675 * 1e18);
+        bytes32 nonce = bytes32(0);
+        uint256 expiration = block.timestamp + 1000000000;
+        (bytes memory signature,) = helper.generateSignatureFromPrivateKey(
+            dc.DEFAULT_ANVIL_KEY2(), amount, nonce, expiration, address(votingPowerExchange)
+        );
+        vm.startPrank(exchanger);
+        votingPowerExchange.exchange(participant2, amount, nonce, expiration, signature);
+        vm.stopPrank();
+        // check the balance of the participant2
+        assertEq(utilityToken.balanceOf(participant2), 102675 * 1e18 - amount); // he got 10000 token in advance
+        uint256 exchangedVotingPower = votingPowerExchange.calculateIncrementedVotingPower(amount, 0);
+        // check the balance of the govToken
+        assertEq(govToken.balanceOf(participant2), exchangedVotingPower);
+    }
+
     function testExchangeWithAnyRoleWhoIsNotExchangerWillRevert(address anyRole) public {
         vm.assume(anyRole != exchanger);
         bytes32 nonce = bytes32(0);
@@ -170,6 +197,39 @@ contract VotingPwoerExchangeTest is Test {
         vm.stopPrank();
     }
 
+    function testExchangeWithAnyExpirationWhichIsExpiredWillRevert(uint256 expiration) public {
+        vm.warp(1641070800);
+        expiration = bound(expiration, 0, block.timestamp - 1);
+        bytes32 nonce = bytes32(0);
+        (bytes memory signature,) = helper.generateSignatureFromPrivateKey(
+            dc.DEFAULT_ANVIL_KEY2(), 1_100 * 1e18, nonce, expiration, address(votingPowerExchange)
+        );
+
+        vm.startPrank(exchanger);
+        vm.expectRevert(VotingPowerExchange.VotingPowerExchange__SignatureExpired.selector);
+        votingPowerExchange.exchange(participant2, 1_100 * 1e18, nonce, expiration, signature);
+        vm.stopPrank();
+    }
+
+    function testExchangeWithAnyExpirationWhichIsNotExpiredWillSucceed(uint256 expiration) public {
+        vm.warp(100);
+        vm.assume(expiration > block.timestamp);
+        bytes32 nonce = bytes32(0);
+        (bytes memory signature,) = helper.generateSignatureFromPrivateKey(
+            dc.DEFAULT_ANVIL_KEY2(), 1_100 * 1e18, nonce, expiration, address(votingPowerExchange)
+        );
+        vm.startPrank(exchanger);
+        votingPowerExchange.exchange(participant2, 1_100 * 1e18, nonce, expiration, signature);
+        vm.stopPrank();
+
+        // check the balance of the participant2
+        assertEq(utilityToken.balanceOf(participant2), 10_000 * 1e18 - 1_100 * 1e18); // he got 10000 token in advance
+        uint256 exchangedVotingPower = votingPowerExchange.calculateIncrementedVotingPower(1_100 * 1e18, 0);
+        // check the balance of the govToken
+        assertEq(govToken.balanceOf(participant2), exchangedVotingPower);
+    }
+
+    ///////////////////////////
     ///// Other functions /////
     ///////////////////////////
     /// The `setVotingPowerCap` function