feat: Allow for token_in_already_in_router

--- don't change below this line ---
ENG-4446 Took 31 minutes


Took 26 seconds

src/encoding/evm/encoder_builders.rs

@@ -21,6 +21,7 @@ pub struct TychoRouterEncoderBuilder {
     chain: Option<Chain>,
     executors_file_path: Option<String>,
     router_address: Option<Bytes>,
+    token_in_already_in_router: Option<bool>,
 }
 
 impl Default for TychoRouterEncoderBuilder {
@@ -36,6 +37,7 @@ impl TychoRouterEncoderBuilder {
             chain: None,
             executors_file_path: None,
             router_address: None,
+            token_in_already_in_router: None,
         }
     }
     pub fn chain(mut self, chain: TychoCommonChain) -> Self {
@@ -62,6 +64,16 @@ impl TychoRouterEncoderBuilder {
         self
     }
 
+    // Sets the `token_in_already_in_router` flag.
+    // If set to true, the encoder will assume that the token in is already in the router.
+    // WARNING: this is an advanced feature and should be used with caution. Make sure you have
+    // checks to make sure that your tokens won't be lost. The Router is not considered safe to hold
+    // tokens, so if this is not done within the same transaction you will lose your tokens.
+    pub fn token_in_already_in_router(mut self, token_in_already_in_router: bool) -> Self {
+        self.token_in_already_in_router = Some(token_in_already_in_router);
+        self
+    }
+
     /// Builds the `TychoRouterEncoder` instance using the configured chain.
     /// Returns an error if either the chain has not been set.
     pub fn build(self) -> Result<Box<dyn TychoEncoder>, EncodingError> {
@@ -88,6 +100,8 @@ impl TychoRouterEncoderBuilder {
                 swap_encoder_registry,
                 self.swapper_pk,
                 tycho_router_address,
+                self.token_in_already_in_router
+                    .unwrap_or(false),
             )?))
         } else {
             Err(EncodingError::FatalError(

src/encoding/evm/strategy_encoder/strategy_encoders.rs

@@ -49,6 +49,7 @@ impl SingleSwapStrategyEncoder {
         swap_encoder_registry: SwapEncoderRegistry,
         swapper_pk: Option<String>,
         router_address: Bytes,
+        token_in_already_in_router: bool,
     ) -> Result<Self, EncodingError> {
         let (permit2, selector) = if let Some(swapper_pk) = swapper_pk {
             (Some(Permit2::new(swapper_pk, chain.clone())?), "singleSwapPermit2(uint256,address,address,uint256,bool,bool,address,((address,uint160,uint48,uint48),address,uint256),bytes,bytes)".to_string())
@@ -68,6 +69,7 @@ impl SingleSwapStrategyEncoder {
                 chain.native_token()?,
                 chain.wrapped_token()?,
                 permit2_is_active,
+                token_in_already_in_router,
             ),
         })
     }
@@ -228,6 +230,7 @@ impl SequentialSwapStrategyEncoder {
         swap_encoder_registry: SwapEncoderRegistry,
         swapper_pk: Option<String>,
         router_address: Bytes,
+        token_in_already_in_router: bool,
     ) -> Result<Self, EncodingError> {
         let (permit2, selector) = if let Some(swapper_pk) = swapper_pk {
             (Some(Permit2::new(swapper_pk, chain.clone())?), "sequentialSwapPermit2(uint256,address,address,uint256,bool,bool,address,((address,uint160,uint48,uint48),address,uint256),bytes,bytes)".to_string())
@@ -251,6 +254,7 @@ impl SequentialSwapStrategyEncoder {
                 chain.native_token()?,
                 chain.wrapped_token()?,
                 permit2_is_active,
+                token_in_already_in_router,
             ),
         })
     }
@@ -440,6 +444,7 @@ impl SplitSwapStrategyEncoder {
         swap_encoder_registry: SwapEncoderRegistry,
         swapper_pk: Option<String>,
         router_address: Bytes,
+        token_in_already_in_router: bool,
     ) -> Result<Self, EncodingError> {
         let (permit2, selector) = if let Some(swapper_pk) = swapper_pk {
             (Some(Permit2::new(swapper_pk, chain.clone())?), "splitSwapPermit2(uint256,address,address,uint256,bool,bool,uint256,address,((address,uint160,uint48,uint48),address,uint256),bytes,bytes)".to_string())
@@ -463,6 +468,7 @@ impl SplitSwapStrategyEncoder {
                 chain.native_token()?,
                 chain.wrapped_token()?,
                 permit2_is_active,
+                token_in_already_in_router,
             ),
         })
     }
@@ -741,6 +747,7 @@ mod tests {
                 swap_encoder_registry,
                 Some(private_key),
                 Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+                false,
             )
             .unwrap();
             let solution = Solution {
@@ -824,6 +831,7 @@ mod tests {
                 swap_encoder_registry,
                 None,
                 Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+                false,
             )
             .unwrap();
             let solution = Solution {
@@ -901,6 +909,7 @@ mod tests {
                 swap_encoder_registry,
                 Some(private_key),
                 Bytes::from("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395"),
+                false,
             )
             .unwrap();
             let solution = Solution {
@@ -953,6 +962,7 @@ mod tests {
                 swap_encoder_registry,
                 Some(private_key),
                 Bytes::from("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395"),
+                false,
             )
             .unwrap();
             let solution = Solution {
@@ -1024,6 +1034,7 @@ mod tests {
                 swap_encoder_registry,
                 Some(private_key),
                 Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+                false,
             )
             .unwrap();
             let solution = Solution {
@@ -1083,6 +1094,7 @@ mod tests {
                 swap_encoder_registry,
                 None,
                 Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+                false,
             )
             .unwrap();
             let solution = Solution {
@@ -1201,6 +1213,7 @@ mod tests {
                 swap_encoder_registry,
                 Some(private_key),
                 Bytes::from("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395"),
+                false,
             )
             .unwrap();
 
@@ -1318,6 +1331,7 @@ mod tests {
                     swap_encoder_registry,
                     None,
                     Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+                    false,
                 )
                 .unwrap();
                 let solution = Solution {
@@ -1399,6 +1413,7 @@ mod tests {
                     swap_encoder_registry,
                     None,
                     Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+                    false,
                 )
                 .unwrap();
                 let solution = Solution {
@@ -1484,6 +1499,7 @@ mod tests {
                     swap_encoder_registry,
                     None,
                     Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+                    false,
                 )
                 .unwrap();
                 let solution = Solution {
@@ -1550,6 +1566,7 @@ mod tests {
                     swap_encoder_registry,
                     None,
                     Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+                    false,
                 )
                 .unwrap();
                 let solution = Solution {
@@ -1649,6 +1666,7 @@ mod tests {
                 swap_encoder_registry,
                 Some(private_key),
                 Bytes::from("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395"),
+                false,
             )
             .unwrap();
             let solution = Solution {
@@ -1758,6 +1776,7 @@ mod tests {
                 swap_encoder_registry,
                 Some(private_key.clone()),
                 Bytes::from("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395"),
+                false,
             )
             .unwrap();
 
@@ -1920,6 +1939,7 @@ mod tests {
                 swap_encoder_registry,
                 Some(private_key.clone()),
                 Bytes::from("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395"),
+                false,
             )
             .unwrap();
 
@@ -2045,6 +2065,7 @@ mod tests {
                 swap_encoder_registry,
                 None,
                 Bytes::from_str("0xA4AD4f68d0b91CFD19687c881e50f3A00242828c").unwrap(),
+                false,
             )
             .unwrap();
 
@@ -2110,6 +2131,7 @@ mod tests {
                 swap_encoder_registry,
                 Some(private_key),
                 Bytes::from("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395"),
+                false,
             )
             .unwrap();
 
@@ -2178,6 +2200,7 @@ mod tests {
                 swap_encoder_registry,
                 Some(private_key),
                 Bytes::from("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395"),
+                false,
             )
             .unwrap();
 
@@ -2265,6 +2288,7 @@ mod tests {
                 swap_encoder_registry,
                 Some(private_key),
                 Bytes::from("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395"),
+                false,
             )
             .unwrap();
             let solution = Solution {
@@ -2367,6 +2391,7 @@ mod tests {
                 swap_encoder_registry,
                 None,
                 Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+                false,
             )
             .unwrap();
 
@@ -2429,6 +2454,7 @@ mod tests {
                 swap_encoder_registry,
                 None,
                 Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+                false,
             )
             .unwrap();
 

src/encoding/evm/strategy_encoder/transfer_optimizations.rs

@@ -11,11 +11,17 @@ pub struct TransferOptimization {
     native_token: Bytes,
     wrapped_token: Bytes,
     permit2: bool,
+    token_in_already_in_router: bool,
 }
 
 impl TransferOptimization {
-    pub fn new(native_token: Bytes, wrapped_token: Bytes, permit2: bool) -> Self {
+    pub fn new(
-        TransferOptimization { native_token, wrapped_token, permit2 }
+        native_token: Bytes,
+        wrapped_token: Bytes,
+        permit2: bool,
+        token_in_already_in_router: bool,
+    ) -> Self {
+        TransferOptimization { native_token, wrapped_token, permit2, token_in_already_in_router }
     }
     /// Returns the transfer method that should be used for the given swap and solution.
     pub fn get_transfer_type(
@@ -38,19 +44,28 @@ impl TransferOptimization {
             TransferType::TransferToProtocol
         } else if is_first_swap {
             if in_transfer_required {
-                if self.permit2 {
+                if self.token_in_already_in_router {
+                    // Transfer from router to pool.
+                    TransferType::TransferToProtocol
+                } else if self.permit2 {
                     // Transfer from swapper to pool using permit2.
                     TransferType::TransferPermit2ToProtocol
                 } else {
                     // Transfer from swapper to pool.
                     TransferType::TransferFromToProtocol
                 }
-            } else if self.permit2 {
+                // in transfer is not necessary for these protocols. Only make a transfer if the
-                // Transfer from swapper to router using permit2.
+                // tokens are not already in the router
-                TransferType::TransferPermit2ToRouter
+            } else if !self.token_in_already_in_router {
+                if self.permit2 {
+                    // Transfer from swapper to router using permit2.
+                    TransferType::TransferPermit2ToRouter
+                } else {
+                    // Transfer from swapper to router.
+                    TransferType::TransferFromToRouter
+                }
             } else {
-                // Transfer from swapper to router.
+                TransferType::None
-                TransferType::TransferFromToRouter
             }
         // all other swaps
         } else if !in_transfer_required || in_between_swap_optimization {
@@ -65,7 +80,6 @@ impl TransferOptimization {
 #[cfg(test)]
 mod tests {
     use alloy_primitives::hex;
-    use tycho_common::Bytes;
 
     use super::*;
 
@@ -95,7 +109,7 @@ mod tests {
             split: 0f64,
             swaps: vec![],
         };
-        let optimization = TransferOptimization::new(eth(), weth(), true);
+        let optimization = TransferOptimization::new(eth(), weth(), true, false);
         let transfer_method = optimization.get_transfer_type(swap.clone(), weth(), false, false);
         assert_eq!(transfer_method, TransferType::TransferPermit2ToProtocol);
     }
@@ -110,7 +124,7 @@ mod tests {
             split: 0f64,
             swaps: vec![],
         };
-        let optimization = TransferOptimization::new(eth(), weth(), false);
+        let optimization = TransferOptimization::new(eth(), weth(), false, false);
         let transfer_method = optimization.get_transfer_type(swap.clone(), weth(), false, false);
         assert_eq!(transfer_method, TransferType::TransferFromToProtocol);
     }
@@ -126,7 +140,7 @@ mod tests {
             split: 0f64,
             swaps: vec![],
         };
-        let optimization = TransferOptimization::new(eth(), weth(), false);
+        let optimization = TransferOptimization::new(eth(), weth(), false, false);
         let transfer_method = optimization.get_transfer_type(swap.clone(), eth(), false, false);
         assert_eq!(transfer_method, TransferType::None);
     }
@@ -142,7 +156,7 @@ mod tests {
             split: 0f64,
             swaps: vec![],
         };
-        let optimization = TransferOptimization::new(eth(), weth(), false);
+        let optimization = TransferOptimization::new(eth(), weth(), false, false);
         let transfer_method = optimization.get_transfer_type(swap.clone(), eth(), true, false);
         assert_eq!(transfer_method, TransferType::TransferToProtocol);
     }
@@ -158,7 +172,7 @@ mod tests {
             split: 0f64,
             swaps: vec![],
         };
-        let optimization = TransferOptimization::new(eth(), weth(), false);
+        let optimization = TransferOptimization::new(eth(), weth(), false, false);
         let transfer_method = optimization.get_transfer_type(swap.clone(), weth(), false, false);
         assert_eq!(transfer_method, TransferType::TransferToProtocol);
     }
@@ -174,7 +188,7 @@ mod tests {
             split: 0f64,
             swaps: vec![],
         };
-        let optimization = TransferOptimization::new(eth(), weth(), false);
+        let optimization = TransferOptimization::new(eth(), weth(), false, false);
         let transfer_method = optimization.get_transfer_type(swap.clone(), weth(), false, false);
         assert_eq!(transfer_method, TransferType::None);
     }
@@ -190,8 +204,40 @@ mod tests {
             split: 0f64,
             swaps: vec![],
         };
-        let optimization = TransferOptimization::new(eth(), weth(), false);
+        let optimization = TransferOptimization::new(eth(), weth(), false, false);
         let transfer_method = optimization.get_transfer_type(swap.clone(), weth(), false, true);
         assert_eq!(transfer_method, TransferType::None);
     }
+
+    #[test]
+    fn test_first_swap_tokens_already_in_router_optimization() {
+        // It is the first swap, tokens are already in the router and the protocol requires the
+        // transfer in
+        let swap = SwapGroup {
+            protocol_system: "uniswap_v2".to_string(),
+            token_in: usdc(),
+            token_out: dai(),
+            split: 0f64,
+            swaps: vec![],
+        };
+        let optimization = TransferOptimization::new(eth(), weth(), false, true);
+        let transfer_method = optimization.get_transfer_type(swap.clone(), usdc(), false, false);
+        assert_eq!(transfer_method, TransferType::TransferToProtocol);
+    }
+
+    #[test]
+    fn test_first_swap_tokens_already_in_router_no_transfer_needed_optimization() {
+        // It is the first swap, tokens are already in the router and the protocol does not require
+        // the transfer in
+        let swap = SwapGroup {
+            protocol_system: "vm:curve".to_string(),
+            token_in: usdc(),
+            token_out: dai(),
+            split: 0f64,
+            swaps: vec![],
+        };
+        let optimization = TransferOptimization::new(eth(), weth(), false, true);
+        let transfer_method = optimization.get_transfer_type(swap.clone(), usdc(), false, false);
+        assert_eq!(transfer_method, TransferType::None);
+    }
 }

src/encoding/evm/tycho_encoders.rs

@@ -39,6 +39,7 @@ impl TychoRouterEncoder {
         swap_encoder_registry: SwapEncoderRegistry,
         swapper_pk: Option<String>,
         router_address: Bytes,
+        token_in_already_in_router: bool,
     ) -> Result<Self, EncodingError> {
         let native_address = chain.native_token()?;
         let wrapped_address = chain.wrapped_token()?;
@@ -48,18 +49,21 @@ impl TychoRouterEncoder {
                 swap_encoder_registry.clone(),
                 swapper_pk.clone(),
                 router_address.clone(),
+                token_in_already_in_router,
             )?,
             sequential_swap_strategy: SequentialSwapStrategyEncoder::new(
                 chain.clone(),
                 swap_encoder_registry.clone(),
                 swapper_pk.clone(),
                 router_address.clone(),
+                token_in_already_in_router,
             )?,
             split_swap_strategy: SplitSwapStrategyEncoder::new(
                 chain,
                 swap_encoder_registry,
                 None,
                 router_address.clone(),
+                token_in_already_in_router,
             )?,
             native_address,
             wrapped_address,
@@ -258,8 +262,8 @@ impl TychoExecutorEncoder {
                 receiver: receiver.clone(),
                 exact_out: solution.exact_out,
                 router_address: None,
-                group_token_in: grouped_swap.input_token.clone(),
+                group_token_in: grouped_swap.token_in.clone(),
-                group_token_out: grouped_swap.output_token.clone(),
+                group_token_out: grouped_swap.token_out.clone(),
                 transfer_type: TransferType::TransferToProtocol,
             };
             let protocol_data = swap_encoder.encode_swap(swap.clone(), encoding_context.clone())?;
@@ -354,6 +358,7 @@ mod tests {
                 get_swap_encoder_registry(),
                 None,
                 Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+                false,
             )
             .unwrap()
         }