feat: add eth fees in flow functions

src/SablierFlow.sol

@@ -191,6 +191,7 @@ contract SablierFlow is
         UD21x18 newRatePerSecond
     )
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -221,6 +222,7 @@ contract SablierFlow is
         bool transferable
     )
         external
+        payable
         override
         noDelegateCall
         returns (uint256 streamId)
@@ -239,6 +241,7 @@ contract SablierFlow is
         uint128 amount
     )
         external
+        payable
         override
         noDelegateCall
         returns (uint256 streamId)
@@ -258,6 +261,7 @@ contract SablierFlow is
         address recipient
     )
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -277,6 +281,7 @@ contract SablierFlow is
         uint128 amount
     )
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -300,6 +305,7 @@ contract SablierFlow is
         Broker calldata broker
     )
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -316,6 +322,7 @@ contract SablierFlow is
     /// @inheritdoc ISablierFlow
     function pause(uint256 streamId)
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -333,6 +340,7 @@ contract SablierFlow is
         uint128 amount
     )
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -349,6 +357,7 @@ contract SablierFlow is
         uint128 amount
     )
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -366,6 +375,7 @@ contract SablierFlow is
     /// @inheritdoc ISablierFlow
     function refundMax(uint256 streamId)
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -384,6 +394,7 @@ contract SablierFlow is
         UD21x18 ratePerSecond
     )
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -402,6 +413,7 @@ contract SablierFlow is
         uint128 amount
     )
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -419,6 +431,7 @@ contract SablierFlow is
     /// @inheritdoc ISablierFlow
     function void(uint256 streamId)
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -436,6 +449,7 @@ contract SablierFlow is
         uint128 amount
     )
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)
@@ -452,6 +466,7 @@ contract SablierFlow is
         address to
     )
         external
+        payable
         override
         noDelegateCall
         notNull(streamId)

src/abstracts/Batch.sol

@@ -13,7 +13,7 @@ abstract contract Batch is IBatch {
     //////////////////////////////////////////////////////////////////////////*/
 
     /// @inheritdoc IBatch
-    function batch(bytes[] calldata calls) external override {
+    function batch(bytes[] calldata calls) external payable override {
         uint256 count = calls.length;
 
         for (uint256 i = 0; i < count; ++i) {

src/abstracts/SablierFlowBase.sol

@@ -205,6 +205,22 @@ abstract contract SablierFlowBase is
                          USER-FACING NON-CONSTANT FUNCTIONS
     //////////////////////////////////////////////////////////////////////////*/
 
+    /// @inheritdoc ISablierFlowBase
+    function collectFees() external override {
+        uint256 feeAmount = address(this).balance;
+
+        // Effect: transfer the fees to the admin.
+        (bool success,) = admin.call{ value: feeAmount }("");
+
+        // Revert if the call failed.
+        if (!success) {
+            revert Errors.SablierFlowBase_FeeTransferFail(admin, feeAmount);
+        }
+
+        // Log the fee withdrawal.
+        emit ISablierFlowBase.CollectFees({ admin: admin, feeAmount: feeAmount });
+    }
+
     /// @inheritdoc ISablierFlowBase
     function collectProtocolRevenue(IERC20 token, address to) external override onlyAdmin {
         uint128 revenue = protocolRevenue[token];

src/interfaces/IBatch.sol

@@ -5,5 +5,5 @@ pragma solidity >=0.8.22;
 interface IBatch {
     /// @notice Allows batched call to self, `this` contract.
     /// @param calls An array of inputs for each call.
-    function batch(bytes[] calldata calls) external;
+    function batch(bytes[] calldata calls) external payable;
 }

src/interfaces/ISablierFlow.sol

@@ -178,7 +178,7 @@ interface ISablierFlow is
     /// @param streamId The ID of the stream to adjust.
     /// @param newRatePerSecond The new rate per second, denoted as a fixed-point number where 1e18 is 1 token
     /// per second.
-    function adjustRatePerSecond(uint256 streamId, UD21x18 newRatePerSecond) external;
+    function adjustRatePerSecond(uint256 streamId, UD21x18 newRatePerSecond) external payable;
 
     /// @notice Creates a new Flow stream by setting the snapshot time to `block.timestamp` and leaving the balance to
     /// zero. The stream is wrapped in an ERC-721 NFT.
@@ -208,6 +208,7 @@ interface ISablierFlow is
         bool transferable
     )
         external
+        payable
         returns (uint256 streamId);
 
     /// @notice Creates a new Flow stream by setting the snapshot time to `block.timestamp` and the balance to `amount`.
@@ -239,6 +240,7 @@ interface ISablierFlow is
         uint128 amount
     )
         external
+        payable
         returns (uint256 streamId);
 
     /// @notice Makes a deposit in a stream.
@@ -255,7 +257,7 @@ interface ISablierFlow is
     /// @param amount The deposit amount, denoted in token's decimals.
     /// @param sender The stream's sender address.
     /// @param recipient The stream's recipient address.
-    function deposit(uint256 streamId, uint128 amount, address sender, address recipient) external;
+    function deposit(uint256 streamId, uint128 amount, address sender, address recipient) external payable;
 
     /// @notice Deposits tokens in a stream and pauses it.
     ///
@@ -269,7 +271,7 @@ interface ISablierFlow is
     ///
     /// @param streamId The ID of the stream to deposit to, and then pause.
     /// @param amount The deposit amount, denoted in token's decimals.
-    function depositAndPause(uint256 streamId, uint128 amount) external;
+    function depositAndPause(uint256 streamId, uint128 amount) external payable;
 
     /// @notice Deposits tokens in a stream.
     ///
@@ -298,7 +300,8 @@ interface ISablierFlow is
         address recipient,
         Broker calldata broker
     )
-        external;
+        external
+        payable;
 
     /// @notice Pauses the stream.
     ///
@@ -314,7 +317,7 @@ interface ISablierFlow is
     /// - `msg.sender` must be the stream's sender.
     ///
     /// @param streamId The ID of the stream to pause.
-    function pause(uint256 streamId) external;
+    function pause(uint256 streamId) external payable;
 
     /// @notice Refunds the provided amount of tokens from the stream to the sender's address.
     ///
@@ -328,7 +331,7 @@ interface ISablierFlow is
     ///
     /// @param streamId The ID of the stream to refund from.
     /// @param amount The amount to refund, denoted in token's decimals.
-    function refund(uint256 streamId, uint128 amount) external;
+    function refund(uint256 streamId, uint128 amount) external payable;
 
     /// @notice Refunds the provided amount of tokens from the stream to the sender's address.
     ///
@@ -342,7 +345,7 @@ interface ISablierFlow is
     ///
     /// @param streamId The ID of the stream to refund from and then pause.
     /// @param amount The amount to refund, denoted in token's decimals.
-    function refundAndPause(uint256 streamId, uint128 amount) external;
+    function refundAndPause(uint256 streamId, uint128 amount) external payable;
 
     /// @notice Refunds the entire refundable amount of tokens from the stream to the sender's address.
     ///
@@ -352,7 +355,7 @@ interface ISablierFlow is
     /// - Refer to the requirements in {refund}.
     ///
     /// @param streamId The ID of the stream to refund from.
-    function refundMax(uint256 streamId) external;
+    function refundMax(uint256 streamId) external payable;
 
     /// @notice Restarts the stream with the provided rate per second.
     ///
@@ -370,7 +373,7 @@ interface ISablierFlow is
     /// @param streamId The ID of the stream to restart.
     /// @param ratePerSecond The amount by which the debt is increasing every second, denoted as a fixed-point number
     /// where 1e18 is 1 token per second.
-    function restart(uint256 streamId, UD21x18 ratePerSecond) external;
+    function restart(uint256 streamId, UD21x18 ratePerSecond) external payable;
 
     /// @notice Restarts the stream with the provided rate per second, and makes a deposit.
     ///
@@ -387,7 +390,7 @@ interface ISablierFlow is
     /// @param ratePerSecond The amount by which the debt is increasing every second, denoted as a fixed-point number
     /// where 1e18 is 1 token per second.
     /// @param amount The deposit amount, denoted in token's decimals.
-    function restartAndDeposit(uint256 streamId, UD21x18 ratePerSecond, uint128 amount) external;
+    function restartAndDeposit(uint256 streamId, UD21x18 ratePerSecond, uint128 amount) external payable;
 
     /// @notice Voids a stream.
     ///
@@ -407,7 +410,7 @@ interface ISablierFlow is
     /// - `msg.sender` must either be the stream's sender, recipient or an approved third party.
     ///
     /// @param streamId The ID of the stream to void.
-    function void(uint256 streamId) external;
+    function void(uint256 streamId) external payable;
 
     /// @notice Withdraws the provided `amount` minus the protocol fee to the provided `to` address.
     ///
@@ -436,6 +439,7 @@ interface ISablierFlow is
         uint128 amount
     )
         external
+        payable
         returns (uint128 withdrawnAmount, uint128 protocolFeeAmount);
 
     /// @notice Withdraws the entire withdrawable amount minus the protocol fee to the provided `to` address.
@@ -458,5 +462,6 @@ interface ISablierFlow is
         address to
     )
         external
+        payable
         returns (uint128 withdrawnAmount, uint128 protocolFeeAmount);
 }

src/interfaces/ISablierFlowBase.sol

@@ -19,6 +19,11 @@ interface ISablierFlowBase is
     IERC721Metadata, // 2 inherited components
     IAdminable // 0 inherited components
 {
+    /// @notice Emitted when the accrued fees are collected.
+    /// @param admin The address of the current contract admin, which has received the fees.
+    /// @param feeAmount The amount of collected fees.
+    event CollectFees(address indexed admin, uint256 indexed feeAmount);
+
     /// @notice Emitted when the contract admin collects protocol revenue accrued.
     /// @param admin The address of the contract admin.
     /// @param token The address of the ERC-20 token the protocol revenue has been collected for.
@@ -145,6 +150,14 @@ interface ISablierFlowBase is
                                NON-CONSTANT FUNCTIONS
     //////////////////////////////////////////////////////////////////////////*/
 
+    /// @notice Collects the accrued fees by transferring them to the contract admin.
+    ///
+    /// @dev Emits a {CollectFees} event.
+    ///
+    /// Notes:
+    /// - If the admin is a contract, it must be able to receive ETH.
+    function collectFees() external;
+
     /// @notice Collect the protocol revenue accrued for the provided ERC-20 token.
     ///
     /// @dev Emits {CollectProtocolRevenue} event.

src/libraries/Errors.sol

@@ -91,6 +91,9 @@ library Errors {
                                  SABLIER-FLOW-BASE
     //////////////////////////////////////////////////////////////////////////*/
 
+    /// @notice Thrown when the fee transfer fails.
+    error SablierFlowBase_FeeTransferFail(address admin, uint256 feeAmount);
+
     /// @notice Thrown when trying to claim protocol revenue when the accrued amount is zero.
     error SablierFlowBase_NoProtocolRevenue(address token);
 

tests/Base.t.sol

@@ -8,6 +8,7 @@ import { ISablierFlow } from "src/interfaces/ISablierFlow.sol";
 import { SablierFlow } from "src/SablierFlow.sol";
 import { ERC20MissingReturn } from "./mocks/ERC20MissingReturn.sol";
 import { ERC20Mock } from "./mocks/ERC20Mock.sol";
+import { ContractWithoutReceive, ContractWithReceive } from "./mocks/Receive.sol";
 import { Assertions } from "./utils/Assertions.sol";
 import { Modifiers } from "./utils/Modifiers.sol";
 import { Users } from "./utils/Types.sol";
@@ -25,9 +26,11 @@ abstract contract Base_Test is Assertions, Modifiers, Test {
                                    TEST CONTRACTS
     //////////////////////////////////////////////////////////////////////////*/
 
+    ContractWithoutReceive internal contractWithoutReceive;
+    ContractWithReceive internal contractWithReceive;
+    ERC20Mock internal dai;
     ERC20Mock internal tokenWithoutDecimals;
     ERC20Mock internal tokenWithProtocolFee;
-    ERC20Mock internal dai;
     ERC20Mock internal usdc;
     ERC20MissingReturn internal usdt;
 
@@ -48,8 +51,13 @@ abstract contract Base_Test is Assertions, Modifiers, Test {
             flow = deployOptimizedSablierFlow();
         }
 
-        // Label the flow contract.
-        vm.label(address(flow), "Flow");
+        contractWithoutReceive = new ContractWithoutReceive();
+        contractWithReceive = new ContractWithReceive();
+
+        // Label the contracts.
+        vm.label({ account: address(flow), newLabel: "Flow" });
+        vm.label({ account: address(contractWithoutReceive), newLabel: "Contract without Receive" });
+        vm.label({ account: address(contractWithReceive), newLabel: "Contract with Receive" });
 
         // Create new tokens and label them.
         createAndLabelTokens();