cr fixes

Author: RafalMagrys

src/PoRepMarket.sol

@@ -146,6 +146,8 @@ contract PoRepMarket is Initializable, AccessControlUpgradeable, UUPSUpgradeable
     error ValidatorAlreadySet(uint256 dealId);
     error InvalidRetrievabilityPct(uint8 value);
     error InvalidIndexingPct(uint8 value);
+    error InvalidRailId();
+    error RailIdAlreadySet();
 
     /**
      * @notice Constructor
@@ -251,6 +253,14 @@ contract PoRepMarket is Initializable, AccessControlUpgradeable, UUPSUpgradeable
         _ensureDealExists(dp);
         _ensureDealCorrectState(dp, DealState.Accepted);
 
+        if (dp.railId != 0) {
+            revert RailIdAlreadySet();
+        }
+
+        if (railId == 0) {
+            revert InvalidRailId();
+        }
+
         if (dp.validator != msg.sender) {
             revert NotTheRegisteredValidator(dealId, msg.sender);
         }

test/PoRepMarket.t.sol

@@ -239,6 +239,34 @@ contract PoRepMarketTest is Test {
         poRepMarket.updateRailId(dealId, railId);
     }
 
+    function testUpdateRailIdRevertsWhenRailIdIsAlreadySet() public {
+        vm.prank(clientAddress);
+        poRepMarket.proposeDeal(defaultRequirements, defaultTerms);
+        vm.prank(providerOwnerAddress);
+        poRepMarket.acceptDeal(dealId);
+        vm.prank(validatorAddress);
+        poRepMarket.updateValidator(dealId);
+        vm.prank(validatorAddress);
+        poRepMarket.updateRailId(dealId, railId);
+
+        vm.expectRevert(abi.encodeWithSelector(PoRepMarket.RailIdAlreadySet.selector));
+        vm.prank(validatorAddress);
+        poRepMarket.updateRailId(dealId, railId);
+    }
+
+    function testUpdateRailIdRevertsWhenRailIdIsInvalid() public {
+        vm.prank(clientAddress);
+        poRepMarket.proposeDeal(defaultRequirements, defaultTerms);
+        vm.prank(providerOwnerAddress);
+        poRepMarket.acceptDeal(dealId);
+        vm.prank(validatorAddress);
+        poRepMarket.updateValidator(dealId);
+
+        vm.expectRevert(abi.encodeWithSelector(PoRepMarket.InvalidRailId.selector));
+        vm.prank(validatorAddress);
+        poRepMarket.updateRailId(dealId, 0);
+    }
+
     function testAcceptDealEmitsDealAcceptedEvent() public {
         vm.prank(clientAddress);
         poRepMarket.proposeDeal(defaultRequirements, defaultTerms);