feat(requests): Add ExecutionRequestsV4::TryFrom<&Requests> using ssz…

…_types.

crates/rpc-types-beacon/Cargo.toml

@@ -31,6 +31,7 @@ serde.workspace = true
 serde_with = { workspace = true, features = ["alloc"] }
 
 thiserror.workspace = true
+ssz_types = { version = "0.9.0", optional = true }
 
 [dev-dependencies]
 serde_json.workspace = true
@@ -42,3 +43,4 @@ ssz = [
     "dep:ethereum_ssz_derive",
     "alloy-rpc-types-engine/ssz",
 ]
+ssz_types = ["dep:ssz_types"]

crates/rpc-types-beacon/src/requests.rs

@@ -16,3 +16,135 @@ pub struct ExecutionRequestsV4 {
     /// The requested consolidations.
     pub consolidations: Vec<ConsolidationRequest>,
 }
+
+#[cfg(feature = "ssz_types")]
+mod from_requests {
+    use crate::requests::ExecutionRequestsV4;
+    use alloy_eips::{
+        eip6110::DepositRequest, eip7002::WithdrawalRequest, eip7251::ConsolidationRequest,
+        eip7685::Requests,
+    };
+    use ssz::DecodeError;
+
+    impl TryFrom<&Requests> for ExecutionRequestsV4 {
+        type Error = Error;
+        fn try_from(value: &Requests) -> Result<Self, Self::Error> {
+            use alloy_eips::{
+                eip6110::DEPOSIT_REQUEST_TYPE, eip7002::WITHDRAWAL_REQUEST_TYPE,
+                eip7251::CONSOLIDATION_REQUEST_TYPE,
+            };
+            use ssz::Decode;
+            use ssz_types::{typenum, VariableList};
+
+            type MaxConsolidationRequestsPerPayload = typenum::U1;
+            type MaxDepositRequestsPerPayload = typenum::U8192;
+            type MaxWithdrawalRequestsPerPayload = typenum::U16;
+
+            let (deposits, withdrawals, consolidations) = value.iter().try_fold(
+                (Vec::new(), Vec::new(), Vec::new()),
+                |mut acc, request| {
+                    if request.is_empty() {
+                        return Err(Error::EmptyRequest);
+                    }
+
+                    match request[0] {
+                        DEPOSIT_REQUEST_TYPE => {
+                            let list: VariableList<
+                                DepositRequest,
+                                MaxWithdrawalRequestsPerPayload,
+                            > = VariableList::from_ssz_bytes(&request[1..])?;
+                            acc.0.extend(Vec::<DepositRequest>::from(list));
+                        }
+                        WITHDRAWAL_REQUEST_TYPE => {
+                            let list: VariableList<
+                                WithdrawalRequest,
+                                MaxDepositRequestsPerPayload,
+                            > = VariableList::from_ssz_bytes(&request[1..])?;
+                            acc.1.extend(Vec::<WithdrawalRequest>::from(list));
+                        }
+                        CONSOLIDATION_REQUEST_TYPE => {
+                            let list: VariableList<
+                                ConsolidationRequest,
+                                MaxConsolidationRequestsPerPayload,
+                            > = VariableList::from_ssz_bytes(&request[1..])?;
+                            acc.2.extend(Vec::<ConsolidationRequest>::from(list));
+                        }
+                        unknown => return Err(Error::UnknownRequestType(unknown)),
+                    }
+                    Ok(acc)
+                },
+            )?;
+
+            Ok(Self { deposits, withdrawals, consolidations })
+        }
+    }
+
+    /// Errors possible converting a [Requests] to [ExecutionRequestsV4]
+    #[derive(Debug)]
+    pub enum Error {
+        /// One of the Bytes is empty.
+        EmptyRequest,
+        /// Bytes prefix is not a known EIP-7685 request_type in Electra.
+        UnknownRequestType(u8),
+        /// Remaining bytes could not be decoded as SSZ requests_data.
+        SszDecodeError(ssz::DecodeError),
+    }
+
+    impl From<DecodeError> for Error {
+        fn from(value: DecodeError) -> Self {
+            Self::SszDecodeError(value)
+        }
+    }
+
+    #[cfg(test)]
+    mod tests {
+        use super::*;
+        use alloy_primitives::Bytes;
+        use std::str::FromStr;
+        #[test]
+        fn test_from_requests() -> Result<(), Error> {
+            let original = Requests::new(vec![
+                // Taken from: https://github.com/ensi321/execution-apis/blob/88c08d6104e9e8ae1d369c2b26c393a0df599e9a/src/engine/openrpc/methods/payload.yaml#L554-L556
+                Bytes::from_str("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").unwrap(),
+                Bytes::from_str("0x01a94f5374fce5edbc8e2a8697c15331677e6ebf0b85103a5617937691dfeeb89b86a80d5dc9e3c9d3a1a0e7ce311e26e0bb732eabaa47ffa288f0d54de28209a62a7d29d0000000000000000000000000000000000000000000000000000010f698daeed734da114470da559bd4b4c7259e1f7952555241dcbc90cf194a2ef676fc6005f3672fada2a3645edb297a75530100000000000000").unwrap(),
+                Bytes::from_str("0x02a94f5374fce5edbc8e2a8697c15331677e6ebf0b85103a5617937691dfeeb89b86a80d5dc9e3c9d3a1a0e7ce311e26e0bb732eabaa47ffa288f0d54de28209a62a7d29d098daeed734da114470da559bd4b4c7259e1f7952555241dcbc90cf194a2ef676fc6005f3672fada2a3645edb297a7553").unwrap(),
+            ]);
+
+            let requests = ExecutionRequestsV4::try_from(&original)?;
+            assert_eq!(requests.deposits.len(), 2);
+            assert_eq!(requests.withdrawals.len(), 2);
+            assert_eq!(requests.consolidations.len(), 1);
+
+            let round_trip: Requests = (&requests).into();
+            assert_eq!(original, round_trip);
+            Ok(())
+        }
+    }
+}
+
+#[cfg(feature = "ssz")]
+mod into_requests {
+    use super::*;
+    use alloy_eips::{
+        eip6110::DEPOSIT_REQUEST_TYPE, eip7002::WITHDRAWAL_REQUEST_TYPE,
+        eip7251::CONSOLIDATION_REQUEST_TYPE, eip7685::Requests,
+    };
+    use ssz::Encode;
+
+    impl From<&ExecutionRequestsV4> for Requests {
+        fn from(val: &ExecutionRequestsV4) -> Self {
+            let deposit_bytes = val.deposits.as_ssz_bytes();
+            let withdrawals_bytes = val.withdrawals.as_ssz_bytes();
+            let consolidations_bytes = val.consolidations.as_ssz_bytes();
+
+            let mut requests = Self::default();
+            requests.push_request_with_type(DEPOSIT_REQUEST_TYPE, deposit_bytes);
+            requests.push_request_with_type(WITHDRAWAL_REQUEST_TYPE, withdrawals_bytes);
+            requests.push_request_with_type(CONSOLIDATION_REQUEST_TYPE, consolidations_bytes);
+            requests
+        }
+    }
+}
+
+#[cfg(feature = "ssz_types")]
+pub use from_requests::Error as FromRequestsError;