Cannot redeem a perk more than once

Author: danitome24

packages/foundry/contracts/KiddoPerks.sol

@@ -25,6 +25,7 @@ contract KiddoPerks is Ownable {
   error KiddoPerks__NotEnoughTokenBalance(
     uint256 id, address by, uint256 tokensRequired
   );
+  error KiddoPerks__PerkAlreadyRedemmed(uint256 id, address by);
 
   KDOToken token;
   address public parent;
@@ -203,12 +204,16 @@ contract KiddoPerks is Ownable {
         perkId, msg.sender, perk.tokensRequired
       );
     }
+    if (s_perksRedeemedBy[perkId][msg.sender]) {
+      revert KiddoPerks__PerkAlreadyRedemmed(perkId, msg.sender);
+    }
 
     bool sent =
       token.transferFrom(msg.sender, address(this), perk.tokensRequired);
     if (!sent) {
       revert("Error on token transfer");
     }
+    s_perksRedeemedBy[perkId][msg.sender] = true;
     emit PerkRedeemed(perkId, msg.sender);
   }
 

packages/foundry/test/KiddoPerks.t.sol

@@ -274,6 +274,30 @@ contract KiddoPerksTest is Test {
     assertEq(initialChildBalance, perkTokensRequired + userFinalBalance);
   }
 
+  function testChildCannotReddemMoreThanOnceAPerk() public withPerkCreated {
+    uint256 perkId = 0;
+    uint256 initialChildBalance = 5 * 10 ** 18;
+    uint256 perkTokensRequired = 2 * 10 ** 18;
+    vm.prank(address(kiddoPerks));
+    kdoToken.mint(CHILD_ONE, initialChildBalance);
+
+    vm.prank(CHILD_ONE);
+    kdoToken.approve(address(kiddoPerks), perkTokensRequired);
+
+    vm.expectEmit(true, true, false, true);
+    emit PerkRedeemed(perkId, CHILD_ONE);
+    vm.prank(CHILD_ONE);
+    kiddoPerks.redeemPerk(perkId);
+
+    vm.expectRevert(
+      abi.encodeWithSelector(
+        KiddoPerks.KiddoPerks__PerkAlreadyRedemmed.selector, perkId, CHILD_ONE
+      )
+    );
+    vm.prank(CHILD_ONE);
+    kiddoPerks.redeemPerk(perkId);
+  }
+
   function testRevertsOnRedeemWhenChildHasNotEnoughTokenBalance()
     public
     withPerkCreated