fix: addresses #32, allowance() amount should reflect transferable am…

…ounts for transferFrom() and transfer()

src/Funnel.sol

@@ -205,16 +205,20 @@ contract Funnel is IFunnel, NativeMetaTransaction, MetaTxContext, Initializable
         return _remainingAllowance(_owner, _spender);
     }
 
+    // @notice fetch remaining allowance between _owner and _spender while accounting for base token allowance.
     function _remainingAllowance(address _owner, address _spender)
         private
         view
         returns (uint256)
     {
         RenewableAllowance memory a = rAllowance[_owner][_spender];
-
+        uint256 baseAllowance = _baseToken.allowance(_owner, address(this));
         uint256 recovered = a.recoveryRate * (block.timestamp - a.lastUpdated);
         uint256 remainingAllowance = a.remaining + recovered;
-        return remainingAllowance > a.maxAmount ? a.maxAmount : remainingAllowance;
+        uint256 currentAllowance = remainingAllowance > a.maxAmount
+            ? a.maxAmount
+            : remainingAllowance;
+        return currentAllowance > baseAllowance ? baseAllowance : currentAllowance;
     }
 
     /// @notice fetch approved max amount and recovery rate

test/Funnel.t.sol

@@ -62,6 +62,15 @@ contract FunnelTest is ERC5827TestSuite {
         funnel.approveRenewable(user2, 100, 101);
     }
 
+    function testBaseTokenAllowance() public {
+        vm.startPrank(user1);
+        token.approve(address(funnel), 100);
+        assertEq(token.allowance(user1, address(funnel)), 100);
+
+        funnel.approveRenewable(address(spender), type(uint256).max, 1);
+        assertEq(funnel.allowance(user1, address(spender)), 100); // reflects base token allowance
+    }
+
     function testInfiniteApproveTransferFrom() public {
         vm.prank(user1);
         funnel.approve(address(this), type(uint256).max);