Refactor QuoterRevert library

.forge-snapshots/Quoter_exactInputSingle_oneForZero_multiplePositions.snap

@@ -1 +1 @@
-144101
+144072

.forge-snapshots/Quoter_exactInputSingle_zeroForOne_multiplePositions.snap

@@ -1 +1 @@
-149552
+149523

.forge-snapshots/Quoter_exactOutputSingle_oneForZero.snap

@@ -1 +1 @@
-78628
+78599

.forge-snapshots/Quoter_exactOutputSingle_zeroForOne.snap

@@ -1 +1 @@
-83436
+83407

.forge-snapshots/Quoter_quoteExactInput_oneHop_1TickLoaded.snap

@@ -1 +1 @@
-120564
+120493

.forge-snapshots/Quoter_quoteExactInput_oneHop_initializedAfter.snap

@@ -1 +1 @@
-145487
+145416

.forge-snapshots/Quoter_quoteExactInput_oneHop_startingInitialized.snap

@@ -1 +1 @@
-79510
+79439

.forge-snapshots/Quoter_quoteExactInput_twoHops.snap

@@ -1 +1 @@
-201252
+201179

.forge-snapshots/Quoter_quoteExactOutput_oneHop_1TickLoaded.snap

@@ -1 +1 @@
-119899
+119828

.forge-snapshots/Quoter_quoteExactOutput_oneHop_2TicksLoaded.snap

@@ -1 +1 @@
-150036
+149965

.forge-snapshots/Quoter_quoteExactOutput_oneHop_initializedAfter.snap

@@ -1 +1 @@
-119967
+119896

.forge-snapshots/Quoter_quoteExactOutput_oneHop_startingInitialized.snap

@@ -1 +1 @@
-96666
+96595

.forge-snapshots/Quoter_quoteExactOutput_twoHops.snap

@@ -1 +1 @@
-200747
+200674

src/base/BaseV4Quoter.sol

@@ -14,8 +14,8 @@ abstract contract BaseV4Quoter is SafeCallback {
     using PoolIdLibrary for PoolId;
 
     error NotEnoughLiquidity(PoolId poolId);
-    error LockFailure();
     error NotSelf();
+    error UnexpectedCallSuccess();
 
     constructor(IPoolManager _poolManager) SafeCallback(_poolManager) {}
 
@@ -27,9 +27,10 @@ abstract contract BaseV4Quoter is SafeCallback {
     }
 
     function _unlockCallback(bytes calldata data) internal override returns (bytes memory) {
-        // Call this contract with the data in question. Each quote path
         (bool success, bytes memory returnData) = address(this).call(data);
-        if (success) return returnData;
+        // Every quote path gathers a quote, and then reverts either with QuoteSwap(quoteAmount) or alternative error
+        if (success) revert UnexpectedCallSuccess();
+        // Bubble the revert string, whether a valid quote or an alternative error
         returnData.bubbleReason();
     }
 

src/lens/Quoter.sol

@@ -26,7 +26,8 @@ contract Quoter is IQuoter, BaseV4Quoter {
         try poolManager.unlock(abi.encodeCall(this._quoteExactInputSingle, (params))) {}
         catch (bytes memory reason) {
             gasEstimate = gasBefore - gasleft();
-            amountOut = reason.parseReturnData();
+            // Extract the quote from QuoteSwap error, or throw if the quote failed
+            amountOut = reason.parseQuoteAmount();
         }
     }
 
@@ -39,7 +40,8 @@ contract Quoter is IQuoter, BaseV4Quoter {
         try poolManager.unlock(abi.encodeCall(this._quoteExactInput, (params))) {}
         catch (bytes memory reason) {
             gasEstimate = gasBefore - gasleft();
-            amountOut = reason.parseReturnData();
+            // Extract the quote from QuoteSwap error, or throw if the quote failed
+            amountOut = reason.parseQuoteAmount();
         }
     }
 
@@ -52,7 +54,8 @@ contract Quoter is IQuoter, BaseV4Quoter {
         try poolManager.unlock(abi.encodeCall(this._quoteExactOutputSingle, (params))) {}
         catch (bytes memory reason) {
             gasEstimate = gasBefore - gasleft();
-            amountIn = reason.parseReturnData();
+            // Extract the quote from QuoteSwap error, or throw if the quote failed
+            amountIn = reason.parseQuoteAmount();
         }
     }
 
@@ -65,7 +68,8 @@ contract Quoter is IQuoter, BaseV4Quoter {
         try poolManager.unlock(abi.encodeCall(this._quoteExactOutput, (params))) {}
         catch (bytes memory reason) {
             gasEstimate = gasBefore - gasleft();
-            amountIn = reason.parseReturnData();
+            // Extract the quote from QuoteSwap error, or throw if the quote failed
+            amountIn = reason.parseQuoteAmount();
         }
     }
 

src/libraries/QuoterRevert.sol

@@ -14,12 +14,14 @@ library QuoterRevert {
     error QuoteSwap(uint256 amount);
 
     /// @notice reverts, where the revert data is the provided bytes
-    /// @dev called when quoting, at the end of simulating a swap, to revert with the swap information as the revert reason
-    function revertQuote(uint256 amountUnspecified) internal pure {
-        revert QuoteSwap(amountUnspecified);
+    /// @dev called when quoting, to record the quote amount in an error
+    /// @dev QuoteSwap is used to differentiate this error from other errors thrown when simulating the swap
+    function revertQuote(uint256 quoteAmount) internal pure {
+        revert QuoteSwap(quoteAmount);
     }
 
-    /// @notice reverts, where the revert data is the provided bytes
+    /// @notice reverts using the revertData as the reason
+    /// @dev to bubble up both the valid QuoteSwap(amount) error, or an alternative error thrown during simulation
     function bubbleReason(bytes memory revertData) internal pure {
         // mload(revertData): the length of the revert data
         // add(revertData, 0x20): a pointer to the start of the revert data
@@ -28,28 +30,20 @@ library QuoterRevert {
         }
     }
 
-    /// @notice check revert reasons are of the expected length; otherwise revert with different message
-    /// @dev called after a swap simulation reverts, to check if the revert was valid encoded quote information, or an internal issue
-    function validateRevertReason(bytes memory reason) internal pure {
+    /// @notice validates whether a revert reason is a valid swap quote or not
+    /// if valid, it decodes the quote to return. Otherwise it reverts.
+    function parseQuoteAmount(bytes memory reason) internal pure returns (uint256 quoteAmount) {
+        // If the error doesnt start with QuoteSwap, we know this isnt a valid quote to parse
+        // Instead it is another revert that was triggered somewhere in the simulation
         if (reason.parseSelector() != QuoteSwap.selector) {
             revert UnexpectedRevertBytes(reason);
         }
-    }
-
-    /// @notice validates a received revert reason from a swap.
-    /// Then, if valid, decodes it into the information generated by a quote
-    function parseReturnData(bytes memory reason) internal pure returns (uint256) {
-        reason.validateRevertReason();
-        return reason.parseAmountUnspecified();
-    }
 
-    /// @notice extracts the amountUnspecified from an encoded QuoteSwap(amountUnspecified)
-    function parseAmountUnspecified(bytes memory reason) internal pure returns (uint256 amountUnspecified) {
         // reason -> reason+0x1f is the length of the reason string
         // reason+0x20 -> reason+0x23 is the selector of QuoteSwap
-        // reason+0x24 -> reason+0x43 is the amountUnspecified
+        // reason+0x24 -> reason+0x43 is the quoteAmount
         assembly ("memory-safe") {
-            amountUnspecified := mload(add(reason, 0x24))
+            quoteAmount := mload(add(reason, 0x24))
         }
     }
 }