From 7fb9f1ff8c12eb9e15945e47635630490da53885 Mon Sep 17 00:00:00 2001
From: Igor Artamonov <igor@artamonov.ru>
Date: Sun, 2 Feb 2025 21:05:34 +0000
Subject: [PATCH] solution: open access to the legacy tx encoder

---
 .../io/emeraldpay/etherjar/tx/Transaction.java    |  2 +-
 .../etherjar/tx/TransactionEncoder.java           | 15 ++++++++++++---
 2 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/Transaction.java b/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/Transaction.java
index 057ad3c..7b5d7f7 100644
--- a/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/Transaction.java
+++ b/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/Transaction.java
@@ -152,7 +152,7 @@ public byte[] hash() {
     }
 
     public byte[] hash(Integer chainId) {
-        byte[] rlp = TransactionEncoder.DEFAULT.encodeStandard(this, false, chainId);
+        byte[] rlp = TransactionEncoder.DEFAULT.encodeLegacy(this, false, chainId);
 
         Keccak.Digest256 keccak = new Keccak.Digest256();
         keccak.update(rlp);
diff --git a/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionEncoder.java b/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionEncoder.java
index 8b1ac03..c68a00e 100644
--- a/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionEncoder.java
+++ b/etherjar-tx/src/main/java/io/emeraldpay/etherjar/tx/TransactionEncoder.java
@@ -37,12 +37,12 @@ public byte[] encode(Transaction tx, boolean includeSignature) {
         }
         if (tx.getType() == TransactionType.STANDARD) {
             if (includeSignature) {
-                return encodeStandard(tx, true, null);
+                return encodeLegacy(tx, true, null);
             } else {
                 Signature signature = tx.getSignature();
                 if (signature.getType() == SignatureType.EIP155) {
                     int chainId = ((SignatureEIP155)signature).getChainId();
-                    return encodeStandard(tx, false, chainId);
+                    return encodeLegacy(tx, false, chainId);
                 } else {
                     throw new IllegalStateException("Neither signature nor chainId specified");
                 }
@@ -51,7 +51,16 @@ public byte[] encode(Transaction tx, boolean includeSignature) {
         throw new IllegalStateException("Unsupported transaction type: " + tx.getType());
     }
 
-    protected byte[] encodeStandard(Transaction tx, boolean includeSignature, Integer chainId) {
+    /**
+     * Encode a Legacy transaction (pre EIP-2718 which introduces a new RLP format).
+     * For legacy transaction you have to encode either the signature or the chainId for unsigned transaction.
+     *
+     * @param tx legacy transaction
+     * @param includeSignature if true, include signature, if false include chainId
+     * @param chainId chain id to include in the transaction if signature is not specified
+     * @return RLP encoded transaction
+     */
+    public byte[] encodeLegacy(Transaction tx, boolean includeSignature, Integer chainId) {
         RlpWriter wrt = new RlpWriter();
         wrt.startList()
             .write(tx.getNonce())