Fixes and tests

src/L2/RegistrarController.sol

@@ -9,7 +9,7 @@ import {StringUtils} from "ens-contracts/ethregistrar/StringUtils.sol";
 
 import {BASE_ETH_NODE, GRACE_PERIOD} from "src/util/Constants.sol";
 import {BaseRegistrar} from "./BaseRegistrar.sol";
-import {IDiscountValidator} from "./interface/IDiscountValidator.sol";
+import {DiscountValidator} from "./discounts/DiscountValidator.sol";
 import {IPriceOracle} from "./interface/IPriceOracle.sol";
 import {L2Resolver} from "./L2Resolver.sol";
 import {IReverseRegistrar} from "./interface/IReverseRegistrar.sol";
@@ -132,12 +132,6 @@ contract RegistrarController is Ownable {
     /// @notice Thrown when the payment received is less than the price.
     error InsufficientValue();
 
-    /// @notice Thrown when the specified discount's validator does not accept the discount for the sender.
-    ///
-    /// @param key The discount being accessed.
-    /// @param data The associated `validationData`.
-    error InvalidDiscount(bytes32 key, bytes data);
-
     /// @notice Thrown when the discount amount is 0.
     ///
     /// @param key The discount being set.
@@ -581,16 +575,18 @@ contract RegistrarController is Ownable {
         active ? activeDiscounts.add(key) : activeDiscounts.remove(key);
     }
 
-    /// Validates that: 
-    ///     1. That the discount is `active`
-    ///     2. That the associated `discountValidator` returns true when `isValidDiscountRegistration` is called.
+    /// @notice Calls the associated discount validator with `msg.sender` and `validationData`.
+    /// 
+    /// @dev This method calls `validateDiscountRegistration` which may revert with `DiscountValidator.InvalidDiscount`.
+    ///
+    /// @param discountKey unique identifier for the discount.
+    /// @param validationData validation data required for discount. 
     function _validateDiscount(bytes32 discountKey, bytes calldata validationData) internal {
         DiscountDetails memory details = discounts[discountKey];
+        if(!details.active) revert InactiveDiscount(discountKey);
 
-        IDiscountValidator validator = IDiscountValidator(details.discountValidator);
-        // if (!validator.validateDiscountRegistration(msg.sender, validationData)) {
-        //     revert InvalidDiscount(discountKey, validationData);
-        // }
+        DiscountValidator validator = DiscountValidator(details.discountValidator);
+        validator.validateDiscountRegistration(msg.sender, validationData);
     }
 
     /// @notice Allows anyone to withdraw the eth accumulated on this contract back to the `paymentReceiver`.

src/L2/discounts/DiscountValidator.sol

@@ -1,20 +1,20 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.23;
 
-/// @title Discount Validator Interface
+/// @title Discount Validato 
 ///
-/// @notice Common interface which all Discount Validators must implement.
-///         The logic specific to each integration must ultimately be consumable as the `bool` returned from
-///         `isValidDiscountRegistration`. Then, upon registration, the integrator should call `validateDiscountRegistration`
-///         allowing discount-specific state writes to occur. 
+/// @notice Discount Validator base contract which must be inherited by implementing validators.
+///         The logic specific to each integration must ultimately be consumable as:
+///             1. A `bool` returned from `isValidDiscountRegistration` for offchain pre-tx validation, and 
+///             2. A call to `validateDiscountRegistration` which will revert if validation fails
 abstract contract DiscountValidator {
     /// @notice Thrown when the specified discount's validator does not accept the discount for the sender.
     ///
-    /// @param claimer The discount being accessed.
+    /// @param claimer The address of the claiming user. 
     /// @param data The associated `validationData`.
     error InvalidDiscount(address claimer, bytes data);
 
-    /// @notice Required implementation for compatibility with IDiscountValidator.
+    /// @notice Required implementation for compatibility with DiscountValidator.
     ///
     /// @dev Each implementation will have unique requirements for the data necessary to perform
     ///     a meaningul validation. Implementations must describe here how to pack relevant `validationData`.
@@ -26,7 +26,16 @@ abstract contract DiscountValidator {
     /// @return `true` if the validation data provided is determined to be valid for the specified claimer, else `false`.
     function isValidDiscountRegistration(address claimer, bytes calldata validationData) public virtual view returns (bool);
 
-    function validateDiscountRegistration(address claimer, bytes calldata validationData) external virtual view {
+
+    /// @notice Required implementation for compaibility with DiscountValidator.
+    /// 
+    /// @dev This method reverts with `InvalidDiscount` if called with for an invalid combination of `claimer` and `validationData`.
+    ///     By default, it simply calls `isValidDiscountRegistration`. If more sophisticated state tracking is required, overwrite this
+    ///     method. Overwriten methods MUST still revert with `InvalidDiscount` should the data fail the validation step. 
+    ///
+    /// @param claimer the discount claimer's address.
+    /// @param validationData opaque bytes for performing the validation.
+    function validateDiscountRegistration(address claimer, bytes calldata validationData) external virtual {
         if(!isValidDiscountRegistration(claimer, validationData)) revert InvalidDiscount(claimer, validationData);
     }
 }

src/L2/interface/IDiscountValidator.sol

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.23;
+
+/// @title Discount Validator Interface
+///
+/// @notice Common interface which all Discount Validators must implement.
+///         The logic specific to each integration must ultimately be consumable as the `bool` returned from
+///         `isValidDiscountRegistration`.
+interface IDiscountValidator {
+    /// @notice Required implementation for compatibility with IDiscountValidator.
+    ///
+    /// @dev Each implementation will have unique requirements for the data necessary to perform
+    ///     a meaningul validation. Implementations must describe here how to pack relevant `validationData`.
+    ///     Ex: `bytes validationData = abi.encode(bytes32 key, bytes32[] proof)`
+    ///
+    /// @param claimer the discount claimer's address.
+    /// @param validationData opaque bytes for performing the validation.
+    ///
+    /// @return `true` if the validation data provided is determined to be valid for the specified claimer, else `false`.
+    function isValidDiscountRegistration(address claimer, bytes calldata validationData) external returns (bool);
+}

test/RegistrarController/DiscountedRegister.t.sol

@@ -1,6 +1,7 @@
 // SPDX-License-Identifier: MIT
 pragma solidity ^0.8.23;
 
+import {DiscountValidator} from "src/L2/discounts/DiscountValidator.sol";
 import {RegistrarControllerBase} from "./RegistrarControllerBase.t.sol";
 import {RegistrarController} from "src/L2/RegistrarController.sol";
 import {IPriceOracle} from "src/L2/interface/IPriceOracle.sol";
@@ -11,6 +12,7 @@ contract DiscountedRegister is RegistrarControllerBase {
         vm.deal(user, 1 ether);
 
         inactiveDiscount.active = false;
+        base.setAvailable(uint256(nameLabel), true);
         vm.prank(owner);
         controller.setDiscountDetails(inactiveDiscount);
         uint256 price = controller.discountedRegisterPrice(name, duration, discountKey);
@@ -26,8 +28,9 @@ contract DiscountedRegister is RegistrarControllerBase {
         controller.setDiscountDetails(_getDefaultDiscount());
         validator.setReturnValue(false);
         uint256 price = controller.discountedRegisterPrice(name, duration, discountKey);
+        base.setAvailable(uint256(nameLabel), true);
 
-        vm.expectRevert(abi.encodeWithSelector(RegistrarController.InvalidDiscount.selector, discountKey, ""));
+        vm.expectRevert(abi.encodeWithSelector(DiscountValidator.InvalidDiscount.selector, user, ""));
         vm.prank(user);
         controller.discountedRegister{value: price}(_getDefaultRegisterRequest(), discountKey, "");
     }
@@ -136,8 +139,9 @@ contract DiscountedRegister is RegistrarControllerBase {
         vm.prank(user);
         controller.discountedRegister{value: price}(request, discountKey, "");
 
-        vm.expectRevert(abi.encodeWithSelector(RegistrarController.AlreadyRegisteredWithDiscount.selector, user));
         request.name = "newname";
+        base.setAvailable(uint256(keccak256(bytes(request.name))),true);
+        vm.expectRevert(abi.encodeWithSelector(RegistrarController.AlreadyRegisteredWithDiscount.selector, user));
         vm.prank(user);
         controller.discountedRegister{value: price}(request, discountKey, "");
     }

test/mocks/MockDiscountValidator.sol

@@ -1,12 +1,12 @@
 //SPDX-License-Identifier: MIT
 pragma solidity ^0.8.23;
 
-import "src/L2/interface/IDiscountValidator.sol";
+import "src/L2/discounts/DiscountValidator.sol";
 
-contract MockDiscountValidator is IDiscountValidator {
+contract MockDiscountValidator is DiscountValidator {
     bool returnValue = true;
 
-    function isValidDiscountRegistration(address, bytes calldata) external view returns (bool) {
+    function isValidDiscountRegistration(address, bytes calldata) public view override returns (bool) {
         return returnValue;
     }