feat(RNG): custom errors

Author: unknownunknown1

contracts/src/rng/BlockhashRNG.sol

@@ -26,12 +26,12 @@ contract BlockHashRNG is IRNG {
     // ************************************* //
 
     modifier onlyByGovernor() {
-        require(governor == msg.sender, "Governor only");
+        if (governor != msg.sender) revert GovernorOnly();
         _;
     }
 
     modifier onlyByConsumer() {
-        require(consumer == msg.sender, "Consumer only");
+        if (consumer != msg.sender) revert ConsumerOnly();
         _;
     }
 

contracts/src/rng/ChainlinkRNG.sol

@@ -42,12 +42,12 @@ contract ChainlinkRNG is IRNG, VRFConsumerBaseV2Plus {
     // ************************************* //
 
     modifier onlyByGovernor() {
-        require(governor == msg.sender, "Governor only");
+        if (governor != msg.sender) revert GovernorOnly();
         _;
     }
 
     modifier onlyByConsumer() {
-        require(consumer == msg.sender, "Consumer only");
+        if (consumer != msg.sender) revert ConsumerOnly();
         _;
     }
 

contracts/src/rng/IRNG.sol

@@ -10,4 +10,7 @@ interface IRNG {
     /// @dev Receive the random number.
     /// @return randomNumber Random number or 0 if not available
     function receiveRandomness() external returns (uint256 randomNumber);
+
+    error GovernorOnly();
+    error ConsumerOnly();
 }

contracts/src/rng/RNGWithFallback.sol

@@ -32,7 +32,7 @@ contract RNGWithFallback is IRNG {
     /// @param _fallbackTimeoutSeconds Time in seconds to wait before falling back to next RNG
     /// @param _rng The RNG address (e.g. Chainlink)
     constructor(address _governor, address _consumer, uint256 _fallbackTimeoutSeconds, IRNG _rng) {
-        require(address(_rng) != address(0), "Invalid default RNG");
+        if (address(_rng) == address(0)) revert InvalidDefaultRNG();
 
         governor = _governor;
         consumer = _consumer;
@@ -45,12 +45,12 @@ contract RNGWithFallback is IRNG {
     // ************************************* //
 
     modifier onlyByGovernor() {
-        require(msg.sender == governor, "Governor only");
+        if (governor != msg.sender) revert GovernorOnly();
         _;
     }
 
     modifier onlyByConsumer() {
-        require(msg.sender == consumer, "Consumer only");
+        if (consumer != msg.sender) revert ConsumerOnly();
         _;
     }
 
@@ -100,4 +100,10 @@ contract RNGWithFallback is IRNG {
         }
         return randomNumber;
     }
+
+    // ************************************* //
+    // *              Errors               * //
+    // ************************************* //
+
+    error InvalidDefaultRNG();
 }

contracts/src/rng/RandomizerRNG.sol

@@ -37,12 +37,12 @@ contract RandomizerRNG is IRNG {
     // ************************************* //
 
     modifier onlyByGovernor() {
-        require(governor == msg.sender, "Governor only");
+        if (governor != msg.sender) revert GovernorOnly();
         _;
     }
 
     modifier onlyByConsumer() {
-        require(consumer == msg.sender, "Consumer only");
+        if (consumer != msg.sender) revert ConsumerOnly();
         _;
     }
 
@@ -110,7 +110,7 @@ contract RandomizerRNG is IRNG {
     /// @param _id The ID of the request.
     /// @param _value The random value answering the request.
     function randomizerCallback(uint256 _id, bytes32 _value) external {
-        require(msg.sender == address(randomizer), "Randomizer only");
+        if (msg.sender != address(randomizer)) revert RandomizerOnly();
         randomNumbers[_id] = uint256(_value);
         emit RequestFulfilled(_id, uint256(_value));
     }
@@ -124,4 +124,10 @@ contract RandomizerRNG is IRNG {
     function receiveRandomness() external view override returns (uint256 randomNumber) {
         randomNumber = randomNumbers[lastRequestId];
     }
+
+    // ************************************* //
+    // *              Errors               * //
+    // ************************************* //
+
+    error RandomizerOnly();
 }

contracts/test/foundry/KlerosCore.t.sol

@@ -12,7 +12,7 @@ import {ISortitionModule} from "../../src/arbitration/interfaces/ISortitionModul
 import {SortitionModuleMock, SortitionModuleBase} from "../../src/test/SortitionModuleMock.sol";
 import {UUPSProxy} from "../../src/proxy/UUPSProxy.sol";
 import {BlockHashRNG} from "../../src/rng/BlockHashRNG.sol";
-import {RNGWithFallback} from "../../src/rng/RNGWithFallback.sol";
+import {RNGWithFallback, IRNG} from "../../src/rng/RNGWithFallback.sol";
 import {RNGMock} from "../../src/test/RNGMock.sol";
 import {PNK} from "../../src/token/PNK.sol";
 import {TestERC20} from "../../src/token/TestERC20.sol";
@@ -3067,15 +3067,15 @@ contract KlerosCoreTest is Test {
         RNGMock rngMock = new RNGMock();
         rngFallback = new RNGWithFallback(msg.sender, address(sortitionModule), fallbackTimeout, rngMock);
 
-        vm.expectRevert(bytes("Consumer only"));
+        vm.expectRevert(IRNG.ConsumerOnly.selector);
         vm.prank(governor);
         rngFallback.requestRandomness();
 
-        vm.expectRevert(bytes("Consumer only"));
+        vm.expectRevert(IRNG.ConsumerOnly.selector);
         vm.prank(governor);
         rngFallback.receiveRandomness();
 
-        vm.expectRevert(bytes("Governor only"));
+        vm.expectRevert(IRNG.GovernorOnly.selector);
         vm.prank(other);
         rngFallback.changeGovernor(other);
         vm.prank(governor);
@@ -3086,14 +3086,14 @@ contract KlerosCoreTest is Test {
         vm.prank(other);
         rngFallback.changeGovernor(governor);
 
-        vm.expectRevert(bytes("Governor only"));
+        vm.expectRevert(IRNG.GovernorOnly.selector);
         vm.prank(other);
         rngFallback.changeConsumer(other);
         vm.prank(governor);
         rngFallback.changeConsumer(other);
         assertEq(rngFallback.consumer(), other, "Wrong consumer");
 
-        vm.expectRevert(bytes("Governor only"));
+        vm.expectRevert(IRNG.GovernorOnly.selector);
         vm.prank(other);
         rngFallback.changeFallbackTimeout(5);