do not reference private methods, improve encode_for_signing docs

crates/primitives/src/transaction/eip1559.rs

@@ -196,6 +196,12 @@ impl TxEip1559 {
     }
 
     /// Encodes the legacy transaction in RLP for signing.
+    ///
+    /// This encodes the transaction as:
+    /// `tx_type || rlp(chain_id, nonce, max_priority_fee_per_gas, max_fee_per_gas, gas_limit, to,
+    /// value, input, access_list)`
+    ///
+    /// Note that there is no rlp header before the transaction type byte.
     pub(crate) fn encode_for_signing(&self, out: &mut dyn bytes::BufMut) {
         out.put_u8(self.tx_type() as u8);
         Header { list: true, payload_length: self.fields_len() }.encode(out);

crates/primitives/src/transaction/eip2930.rs

@@ -160,6 +160,11 @@ impl TxEip2930 {
     }
 
     /// Encodes the legacy transaction in RLP for signing.
+    ///
+    /// This encodes the transaction as:
+    /// `tx_type || rlp(chain_id, nonce, gas_price, gas_limit, to, value, input, access_list)`
+    ///
+    /// Note that there is no rlp header before the transaction type byte.
     pub(crate) fn encode_for_signing(&self, out: &mut dyn bytes::BufMut) {
         out.put_u8(self.tx_type() as u8);
         Header { list: true, payload_length: self.fields_len() }.encode(out);

crates/primitives/src/transaction/eip4844.rs

@@ -295,6 +295,12 @@ impl TxEip4844 {
     }
 
     /// Encodes the legacy transaction in RLP for signing.
+    ///
+    /// This encodes the transaction as:
+    /// `tx_type || rlp(chain_id, nonce, max_priority_fee_per_gas, max_fee_per_gas, gas_limit, to,
+    /// value, input, access_list, max_fee_per_blob_gas, blob_versioned_hashes)`
+    ///
+    /// Note that there is no rlp header before the transaction type byte.
     pub(crate) fn encode_for_signing(&self, out: &mut dyn bytes::BufMut) {
         out.put_u8(self.tx_type() as u8);
         Header { list: true, payload_length: self.fields_len() }.encode(out);

crates/primitives/src/transaction/legacy.rs

@@ -110,6 +110,9 @@ impl TxLegacy {
 
     /// Encodes EIP-155 arguments into the desired buffer. Only encodes values for legacy
     /// transactions.
+    ///
+    /// If a `chain_id` is `Some`, this encodes the `chain_id`, followed by two zeroes, as defined
+    /// by [EIP-155](https://eips.ethereum.org/EIPS/eip-155).
     pub(crate) fn encode_eip155_fields(&self, out: &mut dyn bytes::BufMut) {
         // if this is a legacy transaction without a chain ID, it must be pre-EIP-155
         // and does not need to encode the chain ID for the signature hash encoding
@@ -136,6 +139,12 @@ impl TxLegacy {
     }
 
     /// Encodes the legacy transaction in RLP for signing, including the EIP-155 fields if possible.
+    ///
+    /// If a `chain_id` is `Some`, this encodes the transaction as:
+    /// `rlp(nonce, gas_price, gas_limit, to, value, input, chain_id, 0, 0)`
+    ///
+    /// Otherwise, this encodes the transaction as:
+    /// `rlp(nonce, gas_price, gas_limit, to, value, input)`
     pub(crate) fn encode_for_signing(&self, out: &mut dyn bytes::BufMut) {
         Header { list: true, payload_length: self.fields_len() + self.eip155_fields_len() }
             .encode(out);

crates/primitives/src/transaction/mod.rs

@@ -672,12 +672,6 @@ impl Default for Transaction {
 impl Encodable for Transaction {
     /// This encodes the transaction _without_ the signature, and is only suitable for creating a
     /// hash intended for signing.
-    ///
-    /// See the following docs for how each transaction type is encoded:
-    /// - [TxLegacy](TxLegacy::encode_for_signing)
-    /// - [TxEip2930](TxEip2930::encode_for_signing)
-    /// - [TxEip1559](TxEip1559::encode_for_signing)
-    /// - [TxEip4844](TxEip4844::encode_for_signing)
     fn encode(&self, out: &mut dyn bytes::BufMut) {
         match self {
             Transaction::Legacy(legacy_tx) => {

crates/primitives/src/transaction/pooled.rs

@@ -325,14 +325,13 @@ impl Encodable for PooledTransactionsElement {
     /// For legacy transactions, this encodes the transaction as `rlp(tx-data)`.
     ///
     /// For EIP-2718 transactions, this encodes the transaction as `rlp(tx_type || rlp(tx-data)))`.
-    ///
-    /// The encoding of `tx-data` depends on the transaction type. Refer to these docs for more
-    /// information on the exact format:
-    /// - [Legacy](TxLegacy::encode_with_signature)
-    /// - [EIP-2930](TxEip2930::encode_with_signature)
-    /// - [EIP-1559](TxEip1559::encode_with_signature)
-    /// - [EIP-4844](BlobTransaction::encode_with_type_inner)
     fn encode(&self, out: &mut dyn bytes::BufMut) {
+        // The encoding of `tx-data` depends on the transaction type. Refer to these docs for more
+        // information on the exact format:
+        // - Legacy: TxLegacy::encode_with_signature
+        // - EIP-2930: TxEip2930::encode_with_signature
+        // - EIP-1559: TxEip1559::encode_with_signature
+        // - EIP-4844: BlobTransaction::encode_with_type_inner
         match self {
             Self::Legacy { transaction, signature, .. } => {
                 transaction.encode_with_signature(signature, out)

crates/primitives/src/transaction/sidecar.rs

@@ -372,8 +372,6 @@ impl From<BlobTransactionSidecar> for reth_rpc_types::BlobTransactionSidecar {
 
 impl Encodable for BlobTransactionSidecar {
     /// Encodes the inner [BlobTransactionSidecar] fields as RLP bytes, without a RLP header.
-    ///
-    /// Refer to [BlobTransactionSidecar::encode_inner] for more information on the exact format.
     fn encode(&self, out: &mut dyn BufMut) {
         self.encode_inner(out)
     }