chore: add event to trebuchet for testing indexing

Author: kartojal

script/Deploy.s.sol

@@ -14,7 +14,7 @@ contract DeploySiege is Script {
 
         new BatteringRam(50);
         new Catapult(100);
-        new Trebuchet(200);
+        new Trebuchet(200, msg.sender);
 
         vm.stopBroadcast();
     }

script/Trebuchet.s.sol

@@ -10,7 +10,7 @@ contract DeployTrebuchet is Script {
 
         vm.startBroadcast(deployerPrivateKey);
 
-        new Trebuchet(200);
+        new Trebuchet(200, msg.sender);
 
         vm.stopBroadcast();
     }

src/Trebuchet.sol

@@ -3,17 +3,32 @@ pragma solidity ^0.8.19;
 
 contract Trebuchet {
     uint256 internal _damage;
-    uint256 constant b = 7;
+    address immutable _owner;
 
-    constructor(uint256 damage) {
+    event Attack(uint256 damage);
+    
+    error Unauthorized();
+
+    constructor(uint256 damage, address owner) {
         _damage = damage;
+        _owner = owner;
+    }
+    
+    modifier onlyOwner() {
+        if (msg.sender != _owner) revert Unauthorized();
+        _;
     }
 
     function getAttackDamage() external view returns (uint256) {
         return _damage;
     }
 
-    function attack() external pure returns (string memory) {
+    function attack() external returns (string memory) {
+        emit Attack(_damage);
         return "fiumba!";
     }
+
+    function setDamage(uint256 damage) external onlyOwner {
+        _damage = damage;
+    }
 }

test/Basic.t.sol

@@ -9,10 +9,10 @@ contract TestTrebuchet is Test {
     Trebuchet c;
 
     function setUp() public {
-        c = new Trebuchet(1);
+        c = new Trebuchet(1, address(this));
     }
 
-    function testData() public {
+    function testGetDamage() public {
         assertEq(c.getAttackDamage(), 1);
     }
 }