feat: add helpers for rpc types (#2300)

Author: mattsse

crates/json-rpc/src/packet.rs

@@ -1,4 +1,4 @@
-use crate::{ErrorPayload, Id, Response, SerializedRequest};
+use crate::{ErrorPayload, Id, Response, ResponsePayload, SerializedRequest};
 use alloy_primitives::map::HashSet;
 use serde::{
     de::{self, Deserializer, MapAccess, SeqAccess, Visitor},
@@ -96,6 +96,19 @@ impl RequestPacket {
             }
         }
     }
+
+    /// Returns a all [`SerializedRequest`].
+    pub fn requests(&self) -> &[SerializedRequest] {
+        match self {
+            Self::Single(req) => std::slice::from_ref(req),
+            Self::Batch(req) => req.as_slice(),
+        }
+    }
+
+    /// Returns an iterator over the requests' method names
+    pub fn method_names(&self) -> impl Iterator<Item = &str> + '_ {
+        self.requests().iter().map(|req| req.method())
+    }
 }
 
 /// A [`ResponsePacket`] is a [`Response`] or a batch of responses.
@@ -247,6 +260,24 @@ impl<Payload, ErrData> ResponsePacket<Payload, ErrData> {
         }
     }
 
+    /// Returns a all [`Response`].
+    pub fn responses(&self) -> &[Response<Payload, ErrData>] {
+        match self {
+            Self::Single(req) => std::slice::from_ref(req),
+            Self::Batch(req) => req.as_slice(),
+        }
+    }
+
+    /// Returns an iterator over the responses' payloads.
+    pub fn payloads(&self) -> impl Iterator<Item = &ResponsePayload<Payload, ErrData>> + '_ {
+        self.responses().iter().map(|resp| &resp.payload)
+    }
+
+    /// Returns an iterator over the responses' identifiers.
+    pub fn response_ids(&self) -> impl Iterator<Item = &Id> + '_ {
+        self.responses().iter().map(|resp| &resp.id)
+    }
+
     /// Find responses by a list of IDs.
     ///
     /// This is intended to be used in conjunction with