feat: Support swap grouping for executor strategy

- Also make sure the strategy errors if > 1 group.

src/encoding/evm/strategy_encoder/strategy_encoders.rs

@@ -261,31 +261,47 @@ impl StrategyEncoder for ExecutorStrategyEncoder {
         &self,
         solution: Solution,
     ) -> Result<(Vec<u8>, Bytes, Option<String>), EncodingError> {
-        let swap = solution
+        let grouped_swaps = group_swaps(solution.clone().swaps);
-            .swaps
+        let number_of_groups = grouped_swaps.len();
+        if number_of_groups > 1 {
+            return Err(EncodingError::InvalidInput(format!(
+                "Executor strategy only supports one swap for non-groupable protocols. Found {}",
+                number_of_groups
+            )))
+        }
+
+        let grouped_swap = grouped_swaps
             .first()
-            .ok_or_else(|| EncodingError::InvalidInput("No swaps found in solution".to_string()))?;
+            .ok_or_else(|| EncodingError::FatalError("Swap grouping failed".to_string()))?;
+
+        let receiver = solution.receiver;
+        let router_address = solution.router_address;
 
         let swap_encoder = self
-            .get_swap_encoder(&swap.component.protocol_system)
+            .get_swap_encoder(&grouped_swap.protocol_system)
             .ok_or_else(|| {
                 EncodingError::InvalidInput(format!(
                     "Swap encoder not found for protocol: {}",
-                    swap.component.protocol_system
+                    grouped_swap.protocol_system
                 ))
             })?;
 
+        let mut grouped_protocol_data: Vec<Vec<u8>> = vec![];
+        for swap in grouped_swap.swaps.iter() {
             let encoding_context = EncodingContext {
-            receiver: solution.receiver,
+                receiver: receiver.clone(),
                 exact_out: solution.exact_out,
-            router_address: solution.router_address,
+                router_address: router_address.clone(),
             };
-        let protocol_data = swap_encoder.encode_swap(swap.clone(), encoding_context)?;
+            let protocol_data = swap_encoder.encode_swap(swap.clone(), encoding_context.clone())?;
+            grouped_protocol_data.push(protocol_data);
+        }
 
         let executor_address = Bytes::from_str(swap_encoder.executor_address())
             .map_err(|_| EncodingError::FatalError("Invalid executor address".to_string()))?;
+
         Ok((
-            protocol_data,
+            grouped_protocol_data.abi_encode_packed(),
             executor_address,
             Some(
                 swap_encoder
@@ -397,6 +413,124 @@ mod tests {
         );
         assert_eq!(selector, Some("swap(uint256,bytes)".to_string()));
     }
+
+    #[test]
+    fn test_executor_strategy_encode_too_many_swaps() {
+        let swap_encoder_registry = get_swap_encoder_registry();
+        let encoder = ExecutorStrategyEncoder::new(swap_encoder_registry);
+
+        let token_in = weth();
+        let token_out = Bytes::from("0x6b175474e89094c44da98b954eedeac495271d0f");
+
+        let swap = Swap {
+            component: ProtocolComponent {
+                protocol_system: "uniswap_v2".to_string(),
+                ..Default::default()
+            },
+            token_in: token_in.clone(),
+            token_out: token_out.clone(),
+            split: 0f64,
+        };
+
+        let solution = Solution {
+            exact_out: false,
+            given_token: token_in,
+            given_amount: BigUint::from(1000000000000000000u64),
+            expected_amount: Some(BigUint::from(1000000000000000000u64)),
+            checked_token: token_out,
+            checked_amount: None,
+            sender: Bytes::from_str("0x0000000000000000000000000000000000000000").unwrap(),
+            receiver: Bytes::from_str("0x1d96f2f6bef1202e4ce1ff6dad0c2cb002861d3e").unwrap(),
+            swaps: vec![swap.clone(), swap],
+            direct_execution: true,
+            router_address: Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+            slippage: None,
+            native_action: None,
+        };
+
+        let result = encoder.encode_strategy(solution);
+        assert!(result.is_err());
+    }
+
+    #[test]
+    fn test_executor_strategy_encode_grouped_swaps() {
+        let swap_encoder_registry = get_swap_encoder_registry();
+        let encoder = ExecutorStrategyEncoder::new(swap_encoder_registry);
+
+        let weth = weth();
+        let dai = Bytes::from("0x6b175474e89094c44da98b954eedeac495271d0f");
+        let usdc = Bytes::from("0xa0b86991c6218b36c1d19d4a2e9eb0ce3606eb48");
+
+        let swap_a = Swap {
+            component: ProtocolComponent {
+                id: "0xA478c2975Ab1Ea89e8196811F51A7B7Ade33eB11".to_string(),
+                protocol_system: "uniswap_v4".to_string(),
+                ..Default::default()
+            },
+            token_in: weth.clone(),
+            token_out: dai.clone(),
+            split: 0f64,
+        };
+        let swap_b = Swap {
+            component: ProtocolComponent {
+                id: "0xAE461cA67B15dc8dc81CE7615e0320dA1A9aB8D5".to_string(),
+                protocol_system: "uniswap_v4".to_string(),
+                ..Default::default()
+            },
+            token_in: dai.clone(),
+            token_out: usdc.clone(),
+            split: 0f64,
+        };
+
+        let solution = Solution {
+            exact_out: false,
+            given_token: weth,
+            given_amount: BigUint::from(1000000000000000000u64),
+            expected_amount: Some(BigUint::from(1000000000000000000u64)),
+            checked_token: usdc,
+            checked_amount: None,
+            sender: Bytes::from_str("0x0000000000000000000000000000000000000000").unwrap(),
+            // The receiver was generated with `makeAddr("bob") using forge`
+            receiver: Bytes::from_str("0x1d96f2f6bef1202e4ce1ff6dad0c2cb002861d3e").unwrap(),
+            swaps: vec![swap_a, swap_b],
+            direct_execution: true,
+            router_address: Bytes::from_str("0x3Ede3eCa2a72B3aeCC820E955B36f38437D01395").unwrap(),
+            slippage: None,
+            native_action: None,
+        };
+
+        let (protocol_data, executor_address, selector) = encoder
+            .encode_strategy(solution)
+            .unwrap();
+        let hex_protocol_data = encode(&protocol_data);
+        assert_eq!(
+            executor_address,
+            Bytes::from_str("0x5c2f5a71f67c01775180adc06909288b4c329308").unwrap()
+        );
+        assert_eq!(
+            hex_protocol_data,
+            String::from(concat!(
+                // in token
+                "c02aaa39b223fe8d0a0e5c4f27ead9083c756cc2",
+                // component id
+                "a478c2975ab1ea89e8196811f51a7b7ade33eb11",
+                // receiver
+                "1d96f2f6bef1202e4ce1ff6dad0c2cb002861d3e",
+                // zero for one
+                "00",
+                // in token
+                "6b175474e89094c44da98b954eedeac495271d0f",
+                // component id
+                "ae461ca67b15dc8dc81ce7615e0320da1a9ab8d5",
+                // receiver
+                "1d96f2f6bef1202e4ce1ff6dad0c2cb002861d3e",
+                // zero for one
+                "01",
+            ))
+        );
+        assert_eq!(selector, Some("swap(uint256,bytes)".to_string()));
+    }
+
     #[rstest]
     #[case::no_check_no_slippage(
         None,