tob I04: add donate event (#845)

* add donate event

* fix snapshots

.forge-snapshots/donate gas with 1 token.snap

@@ -1 +1 @@
-104429
+106488

.forge-snapshots/donate gas with 2 tokens.snap

@@ -1 +1 @@
-144017
+146076

.forge-snapshots/poolManager bytecode size.snap

@@ -1 +1 @@
-24354
+24404

src/PoolManager.sol

@@ -253,7 +253,8 @@ contract PoolManager is IPoolManager, ProtocolFees, NoDelegateCall, ERC6909Claim
         noDelegateCall
         returns (BalanceDelta delta)
     {
-        Pool.State storage pool = _getPool(key.toId());
+        PoolId poolId = key.toId();
+        Pool.State storage pool = _getPool(poolId);
         pool.checkPoolInitialized();
 
         key.hooks.beforeDonate(key, amount0, amount1, hookData);
@@ -262,6 +263,9 @@ contract PoolManager is IPoolManager, ProtocolFees, NoDelegateCall, ERC6909Claim
 
         _accountPoolBalanceDelta(key, delta, msg.sender);
 
+        // event is emitted before the afterDonate call to ensure events are always emitted in order
+        emit Donate(poolId, msg.sender, amount0, amount1);
+
         key.hooks.afterDonate(key, amount0, amount1, hookData);
     }
 

src/interfaces/IPoolManager.sol

@@ -98,6 +98,13 @@ interface IPoolManager is IProtocolFees, IERC6909Claims, IExtsload, IExttload {
         uint24 fee
     );
 
+    /// @notice Emitted for donations
+    /// @param id The abi encoded hash of the pool key struct for the pool that was donated to
+    /// @param sender The address that initiated the donate call
+    /// @param amount0 The amount donated in currency0
+    /// @param amount1 The amount donated in currency1
+    event Donate(PoolId indexed id, address indexed sender, uint256 amount0, uint256 amount1);
+
     /// @notice All interactions on the contract that account deltas require unlocking. A caller that calls `unlock` must implement
     /// `IUnlockCallback(msg.sender).unlockCallback(data)`, where they interact with the remaining functions on this contract.
     /// @dev The only functions callable without an unlocking are `initialize` and `updateDynamicLPFee`

test/PoolManager.t.sol

@@ -63,6 +63,8 @@ contract PoolManagerTest is Test, Deployers, GasSnapshot {
         uint24 fee
     );
 
+    event Donate(PoolId indexed id, address indexed sender, uint256 amount0, uint256 amount1);
+
     event Transfer(
         address caller, address indexed sender, address indexed receiver, uint256 indexed id, uint256 amount
     );
@@ -876,6 +878,15 @@ contract PoolManagerTest is Test, Deployers, GasSnapshot {
         snapLastCall("donate gas with 1 token");
     }
 
+    function test_fuzz_donate_emits_event(uint256 amount0, uint256 amount1) public {
+        amount0 = bound(amount0, 0, uint256(int256(type(int128).max)));
+        amount1 = bound(amount1, 0, uint256(int256(type(int128).max)));
+
+        vm.expectEmit(true, true, false, true, address(manager));
+        emit Donate(key.toId(), address(donateRouter), uint256(amount0), uint256(amount1));
+        donateRouter.donate(key, amount0, amount1, ZERO_BYTES);
+    }
+
     function test_take_failsWithNoLiquidity() public {
         deployFreshManagerAndRouters();