Set up forge tests

pkg/vault/contracts/test/MevRouterMock.sol

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+pragma solidity ^0.8.24;
+
+import { IERC4626 } from "@openzeppelin/contracts/interfaces/IERC4626.sol";
+import { IPermit2 } from "permit2/src/interfaces/IPermit2.sol";
+
+import { IWETH } from "@balancer-labs/v3-interfaces/contracts/solidity-utils/misc/IWETH.sol";
+import { IVault } from "@balancer-labs/v3-interfaces/contracts/vault/IVault.sol";
+
+import { MevRouter } from "../MevRouter.sol";
+
+string constant MOCK_MEV_ROUTER_VERSION = "Mock Router v1";
+
+contract MevRouterMock is MevRouter {
+    error MockErrorCode();
+
+    constructor(
+        IVault vault,
+        IWETH weth,
+        IPermit2 permit2,
+        MevRouterParams memory params
+    ) MevRouter(vault, weth, permit2, MOCK_MEV_ROUTER_VERSION, params) {
+        // solhint-disable-previous-line no-empty-blocks
+    }
+}

pkg/vault/contracts/test/MevTaxCollectorMock.sol

@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+pragma solidity ^0.8.24;
+
+import { IMevTaxCollector } from "@balancer-labs/v3-interfaces/contracts/vault/IMevTaxCollector.sol";
+
+contract MevTaxCollectorMock is IMevTaxCollector {
+    function chargeMevTax(address pool) external payable {
+        return;
+    }
+}

pkg/vault/test/foundry/MevRouter.t.sol

@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+pragma solidity ^0.8.24;
+
+import "forge-std/Test.sol";
+
+import { IAuthentication } from "@balancer-labs/v3-interfaces/contracts/solidity-utils/helpers/IAuthentication.sol";
+import { IMevRouter } from "@balancer-labs/v3-interfaces/contracts/vault/IMevRouter.sol";
+
+import { BaseVaultTest } from "./utils/BaseVaultTest.sol";
+
+contract MevRouterTest is BaseVaultTest {
+    function setUp() public override {
+        super.setUp();
+
+        authorizer.grantRole(mevRouter.getActionId(IMevRouter.disableMevTax.selector), admin);
+        authorizer.grantRole(mevRouter.getActionId(IMevRouter.enableMevTax.selector), admin);
+    }
+
+    function testDisableMevTax() public {
+        assertTrue(mevRouter.isMevTaxEnabled(), "Mev Tax is not enabled");
+        vm.prank(admin);
+        mevRouter.disableMevTax();
+        assertFalse(mevRouter.isMevTaxEnabled(), "Mev Tax is not disabled");
+    }
+
+    function testDisableMevTaxIsAuthenticated() public {
+        vm.expectRevert(IAuthentication.SenderNotAllowed.selector);
+        mevRouter.disableMevTax();
+    }
+
+    function testEnableMevTax() public {
+        vm.prank(admin);
+        mevRouter.disableMevTax();
+        assertFalse(mevRouter.isMevTaxEnabled(), "Mev Tax is not disabled");
+        vm.prank(admin);
+        mevRouter.enableMevTax();
+        assertTrue(mevRouter.isMevTaxEnabled(), "Mev Tax is not enabled");
+    }
+
+    function testEnableMevTaxIsAuthenticated() public {
+        vm.expectRevert(IAuthentication.SenderNotAllowed.selector);
+        mevRouter.enableMevTax();
+    }
+}

pkg/vault/test/foundry/utils/BaseVaultTest.sol

@@ -28,6 +28,7 @@ import { PoolFactoryMock } from "../../../contracts/test/PoolFactoryMock.sol";
 import { PoolHooksMock } from "../../../contracts/test/PoolHooksMock.sol";
 import { RouterMock } from "../../../contracts/test/RouterMock.sol";
 import { BufferRouterMock } from "../../../contracts/test/BufferRouterMock.sol";
+import { MevRouterMock } from "../../../contracts/test/MevRouterMock.sol";
 import { VaultStorage } from "../../../contracts/VaultStorage.sol";
 import { PoolMock } from "../../../contracts/test/PoolMock.sol";
 
@@ -84,6 +85,7 @@ abstract contract BaseVaultTest is VaultContractsDeployer, VaultStorage, BaseTes
     RouterMock internal router;
     BatchRouterMock internal batchRouter;
     BufferRouterMock internal bufferRouter;
+    MevRouterMock internal mevRouter;
     PoolFactoryMock internal factoryMock;
     RateProviderMock internal rateProvider;
     CompositeLiquidityRouterMock internal compositeLiquidityRouter;
@@ -160,6 +162,8 @@ abstract contract BaseVaultTest is VaultContractsDeployer, VaultStorage, BaseTes
         vm.label(address(compositeLiquidityRouter), "composite liquidity router");
         bufferRouter = deployBufferRouterMock(IVault(address(vault)), weth, permit2);
         vm.label(address(bufferRouter), "buffer router");
+        mevRouter = deployMevRouterMock(IVault(address(vault)), weth, permit2);
+        vm.label(address(mevRouter), "mev router");
         feeController = vault.getProtocolFeeController();
         vm.label(address(feeController), "fee controller");
 
@@ -184,6 +188,7 @@ abstract contract BaseVaultTest is VaultContractsDeployer, VaultStorage, BaseTes
             permit2.approve(address(tokens[i]), address(router), type(uint160).max, type(uint48).max);
             permit2.approve(address(tokens[i]), address(bufferRouter), type(uint160).max, type(uint48).max);
             permit2.approve(address(tokens[i]), address(batchRouter), type(uint160).max, type(uint48).max);
+            permit2.approve(address(tokens[i]), address(mevRouter), type(uint160).max, type(uint48).max);
             permit2.approve(address(tokens[i]), address(compositeLiquidityRouter), type(uint160).max, type(uint48).max);
         }
 
@@ -192,6 +197,7 @@ abstract contract BaseVaultTest is VaultContractsDeployer, VaultStorage, BaseTes
             permit2.approve(address(erc4626Tokens[i]), address(router), type(uint160).max, type(uint48).max);
             permit2.approve(address(erc4626Tokens[i]), address(bufferRouter), type(uint160).max, type(uint48).max);
             permit2.approve(address(erc4626Tokens[i]), address(batchRouter), type(uint160).max, type(uint48).max);
+            permit2.approve(address(erc4626Tokens[i]), address(mevRouter), type(uint160).max, type(uint48).max);
             permit2.approve(
                 address(erc4626Tokens[i]),
                 address(compositeLiquidityRouter),
@@ -212,12 +218,14 @@ abstract contract BaseVaultTest is VaultContractsDeployer, VaultStorage, BaseTes
             bpt.approve(address(router), type(uint256).max);
             bpt.approve(address(bufferRouter), type(uint256).max);
             bpt.approve(address(batchRouter), type(uint256).max);
+            bpt.approve(address(mevRouter), type(uint256).max);
             bpt.approve(address(compositeLiquidityRouter), type(uint256).max);
 
             IERC20(bpt).approve(address(permit2), type(uint256).max);
             permit2.approve(address(bpt), address(router), type(uint160).max, type(uint48).max);
             permit2.approve(address(bpt), address(bufferRouter), type(uint160).max, type(uint48).max);
             permit2.approve(address(bpt), address(batchRouter), type(uint160).max, type(uint48).max);
+            permit2.approve(address(bpt), address(mevRouter), type(uint160).max, type(uint48).max);
             permit2.approve(address(bpt), address(compositeLiquidityRouter), type(uint160).max, type(uint48).max);
 
             vm.stopPrank();

pkg/vault/test/foundry/utils/VaultContractsDeployer.sol

@@ -10,6 +10,8 @@ import { IPermit2 } from "permit2/src/interfaces/IPermit2.sol";
 import { IVault } from "@balancer-labs/v3-interfaces/contracts/vault/IVault.sol";
 import { IAuthorizer } from "@balancer-labs/v3-interfaces/contracts/vault/IAuthorizer.sol";
 import { IVaultMock } from "@balancer-labs/v3-interfaces/contracts/test/IVaultMock.sol";
+import { IMevRouter } from "@balancer-labs/v3-interfaces/contracts/vault/IMevRouter.sol";
+import { IMevTaxCollector } from "@balancer-labs/v3-interfaces/contracts/vault/IMevTaxCollector.sol";
 import { IWETH } from "@balancer-labs/v3-interfaces/contracts/solidity-utils/misc/IWETH.sol";
 import { HooksConfigLibMock } from "@balancer-labs/v3-vault/contracts/test/HooksConfigLibMock.sol";
 import { BaseContractsDeployer } from "@balancer-labs/v3-solidity-utils/test/foundry/utils/BaseContractsDeployer.sol";
@@ -35,6 +37,8 @@ import { RateProviderMock } from "../../../contracts/test/RateProviderMock.sol";
 import { RouterCommonMock } from "../../../contracts/test/RouterCommonMock.sol";
 import { RouterMock } from "../../../contracts/test/RouterMock.sol";
 import { BufferRouterMock } from "../../../contracts/test/BufferRouterMock.sol";
+import { MevRouterMock } from "../../../contracts/test/MevRouterMock.sol";
+import { MevTaxCollectorMock } from "../../../contracts/test/MevTaxCollectorMock.sol";
 
 /**
  * @notice This contract contains functions for deploying mocks and contracts related to the "Vault".
@@ -287,6 +291,30 @@ contract VaultContractsDeployer is BaseContractsDeployer {
         }
     }
 
+    function deployMevRouterMock(IVault vault, IWETH weth, IPermit2 permit2) internal returns (MevRouterMock) {
+        IMevTaxCollector collector = new MevTaxCollectorMock();
+
+        IMevRouter.MevRouterParams memory params = IMevRouter.MevRouterParams({
+            mevTaxCollector: collector,
+            mevTaxMultiplier: 9,
+            priorityGasThreshold: 1e18
+        });
+
+        if (reusingArtifacts) {
+            return
+                MevRouterMock(
+                    payable(
+                        deployCode(
+                            _computeVaultTestPath(type(MevRouterMock).name),
+                            abi.encode(vault, weth, permit2, params)
+                        )
+                    )
+                );
+        } else {
+            return new MevRouterMock(vault, weth, permit2, params);
+        }
+    }
+
     function _computeVaultPath(string memory name) private view returns (string memory) {
         return string(abi.encodePacked(artifactsRootDir, "contracts/", name, ".sol/", name, ".json"));
     }