Completely remove the flash loan logic (#779)

* feat: remove flash loan logic

test: update tests accordingly
docs: remove flash loan reference in README

* test: re-add setProtocolFee tests

README.md

@@ -104,10 +104,6 @@ it is explained in depth [here](https://github.com/sablier-labs/v2-core/wiki/Tes
 The list of all deployment addresses can be found [here](https://docs.sablier.com). For guidance on the deploy scripts,
 see the [Deployments wiki](https://github.com/sablier-labs/v2-core/wiki/Deployments).
 
-It is worth noting that not every file in this repository is included in the current deployments. For instance, the
-`SablierV2FlashLoan` abstract is not inherited by any contract on the `main` branch, but we have kept it in version
-control because we may decide to use it in the future.
-
 ## Security
 
 The codebase has undergone rigorous audits by leading security experts from Cantina, as well as independent auditors.

script/Init.s.sol

@@ -7,7 +7,6 @@ import { ud60x18 } from "@prb/math/src/UD60x18.sol";
 
 import { Solarray } from "solarray/src/Solarray.sol";
 
-import { ISablierV2Comptroller } from "../src/interfaces/ISablierV2Comptroller.sol";
 import { ISablierV2LockupDynamic } from "../src/interfaces/ISablierV2LockupDynamic.sol";
 import { ISablierV2LockupLinear } from "../src/interfaces/ISablierV2LockupLinear.sol";
 import { Broker, LockupDynamic, LockupLinear } from "../src/types/DataTypes.sol";
@@ -21,7 +20,6 @@ interface IERC20Mint {
 /// @notice Initializes the protocol by setting up the comptroller and creating some streams.
 contract Init is BaseScript {
     function run(
-        ISablierV2Comptroller comptroller,
         ISablierV2LockupLinear lockupLinear,
         ISablierV2LockupDynamic lockupDynamic,
         IERC20 asset
@@ -32,18 +30,6 @@ contract Init is BaseScript {
         address sender = broadcaster;
         address recipient = vm.addr(vm.deriveKey({ mnemonic: mnemonic, index: 1 }));
 
-        /*//////////////////////////////////////////////////////////////////////////
-                                        COMPTROLLER
-        //////////////////////////////////////////////////////////////////////////*/
-
-        // Enable the ERC-20 asset for flash loaning.
-        if (!comptroller.isFlashAsset(asset)) {
-            comptroller.toggleFlashAsset(asset);
-        }
-
-        // Set the flash fee to 0.05%.
-        comptroller.setFlashFee({ newFlashFee: ud60x18(0.0005e18) });
-
         /*//////////////////////////////////////////////////////////////////////////
                                        LOCKUP-LINEAR
         //////////////////////////////////////////////////////////////////////////*/

src/SablierV2Comptroller.sol

@@ -36,12 +36,6 @@ contract SablierV2Comptroller is
                                    PUBLIC STORAGE
     //////////////////////////////////////////////////////////////////////////*/
 
-    /// @inheritdoc ISablierV2Comptroller
-    UD60x18 public override flashFee;
-
-    /// @inheritdoc ISablierV2Comptroller
-    mapping(IERC20 asset => bool supported) public override isFlashAsset;
-
     /// @inheritdoc ISablierV2Comptroller
     mapping(IERC20 asset => UD60x18 fee) public override protocolFees;
 
@@ -60,16 +54,6 @@ contract SablierV2Comptroller is
                          USER-FACING NON-CONSTANT FUNCTIONS
     //////////////////////////////////////////////////////////////////////////*/
 
-    /// @inheritdoc ISablierV2Comptroller
-    function setFlashFee(UD60x18 newFlashFee) external override onlyAdmin {
-        // Effects: set the new flash fee.
-        UD60x18 oldFlashFee = flashFee;
-        flashFee = newFlashFee;
-
-        // Log the change of the flash fee.
-        emit ISablierV2Comptroller.SetFlashFee({ admin: msg.sender, oldFlashFee: oldFlashFee, newFlashFee: newFlashFee });
-    }
-
     /// @inheritdoc ISablierV2Comptroller
     function setProtocolFee(IERC20 asset, UD60x18 newProtocolFee) external override onlyAdmin {
         // Effects: set the new global fee.
@@ -84,14 +68,4 @@ contract SablierV2Comptroller is
             newProtocolFee: newProtocolFee
         });
     }
-
-    /// @inheritdoc ISablierV2Comptroller
-    function toggleFlashAsset(IERC20 asset) external override onlyAdmin {
-        // Effects: enable the ERC-20 asset for flash loaning.
-        bool oldFlag = isFlashAsset[asset];
-        isFlashAsset[asset] = !oldFlag;
-
-        // Log the change of the flash asset flag.
-        emit ISablierV2Comptroller.ToggleFlashAsset({ admin: msg.sender, asset: asset, newFlag: !oldFlag });
-    }
 }

src/interfaces/ISablierV2Comptroller.sol

@@ -14,41 +14,17 @@ interface ISablierV2Comptroller is IAdminable {
                                        EVENTS
     //////////////////////////////////////////////////////////////////////////*/
 
-    /// @notice Emitted when the admin sets a new flash fee.
-    /// @param admin The address of the contract admin.
-    /// @param oldFlashFee The old flash fee, denoted as a fixed-point number.
-    /// @param newFlashFee The new flash fee, denoted as a fixed-point number.
-    event SetFlashFee(address indexed admin, UD60x18 oldFlashFee, UD60x18 newFlashFee);
-
     /// @notice Emitted when the admin sets a new protocol fee for the provided ERC-20 asset.
     /// @param admin The address of the contract admin.
     /// @param asset The contract address of the ERC-20 asset the new protocol fee has been set for.
     /// @param oldProtocolFee The old protocol fee, denoted as a fixed-point number.
     /// @param newProtocolFee The new protocol fee, denoted as a fixed-point number.
     event SetProtocolFee(address indexed admin, IERC20 indexed asset, UD60x18 oldProtocolFee, UD60x18 newProtocolFee);
 
-    /// @notice Emitted when the admin enables or disables an ERC-20 asset for flash loaning.
-    /// @param admin The address of the contract admin.
-    /// @param asset The contract address of the ERC-20 asset to toggle.
-    /// @param newFlag Whether the ERC-20 asset can be flash loaned.
-    event ToggleFlashAsset(address indexed admin, IERC20 indexed asset, bool newFlag);
-
     /*//////////////////////////////////////////////////////////////////////////
                                  CONSTANT FUNCTIONS
     //////////////////////////////////////////////////////////////////////////*/
 
-    /// @notice Retrieves the global flash fee, denoted as a fixed-point number where 1e18 is 100%.
-    ///
-    /// @dev Notes:
-    /// - This fee represents a percentage, not an amount. Do not confuse it with {IERC3156FlashLender.flashFee},
-    /// which calculates the fee amount for a specified flash loan amount.
-    /// - Unlike the protocol fee, this is a global fee applied to all flash loans, not a per-asset fee.
-    function flashFee() external view returns (UD60x18 fee);
-
-    /// @notice Retrieves a flag indicating whether the provided ERC-20 asset can be flash loaned.
-    /// @param token The contract address of the ERC-20 asset to check.
-    function isFlashAsset(IERC20 token) external view returns (bool result);
-
     /// @notice Retrieves the protocol fee for all streams created with the provided ERC-20 asset.
     /// @param asset The contract address of the ERC-20 asset to query.
     /// @return fee The protocol fee denoted as a fixed-point number where 1e18 is 100%.
@@ -58,19 +34,6 @@ interface ISablierV2Comptroller is IAdminable {
                                NON-CONSTANT FUNCTIONS
     //////////////////////////////////////////////////////////////////////////*/
 
-    /// @notice Updates the flash fee charged on all flash loans made with any ERC-20 asset.
-    ///
-    /// @dev Emits a {SetFlashFee} event.
-    ///
-    /// Notes:
-    /// - Does not revert if the fee is the same.
-    ///
-    /// Requirements:
-    /// - `msg.sender` must be the contract admin.
-    ///
-    /// @param newFlashFee The new flash fee to set, denoted as a fixed-point number where 1e18 is 100%.
-    function setFlashFee(UD60x18 newFlashFee) external;
-
     /// @notice Sets a new protocol fee that will be charged on all streams created with the provided ERC-20 asset.
     ///
     /// @dev Emits a {SetProtocolFee} event.
@@ -86,14 +49,4 @@ interface ISablierV2Comptroller is IAdminable {
     /// @param asset The contract address of the ERC-20 asset to update the fee for.
     /// @param newProtocolFee The new protocol fee, denoted as a fixed-point number where 1e18 is 100%.
     function setProtocolFee(IERC20 asset, UD60x18 newProtocolFee) external;
-
-    /// @notice Toggles the flash loanability of an ERC-20 asset.
-    ///
-    /// @dev Emits a {ToggleFlashAsset} event.
-    ///
-    /// Requirements:
-    /// - `msg.sender` must be the admin.
-    ///
-    /// @param asset The address of the ERC-20 asset to toggle.
-    function toggleFlashAsset(IERC20 asset) external;
 }