From 074edff1b4cdbc9989e2ee9f996437a28a3ba182 Mon Sep 17 00:00:00 2001
From: jangko <jangko128@gmail.com>
Date: Fri, 18 Aug 2023 17:52:55 +0700
Subject: [PATCH] EIP-4788: Add parentBeaconBlockRoot field to BlockHeader

---
 eth/common/eth_types.nim        |  1 +
 tests/common/test_eth_types.nim | 25 +++++++++++++++++++++----
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/eth/common/eth_types.nim b/eth/common/eth_types.nim
index 7ebd89b1..ba942bbe 100644
--- a/eth/common/eth_types.nim
+++ b/eth/common/eth_types.nim
@@ -143,6 +143,7 @@ type
     withdrawalsRoot*: Option[Hash256]   # EIP-4895
     blobGasUsed*:     Option[uint64]    # EIP-4844
     excessBlobGas*:   Option[uint64]    # EIP-4844
+    parentBeaconBlockRoot*: Option[Hash256] # EIP-4788
 
   BlockBody* = object
     transactions*:  seq[Transaction]
diff --git a/tests/common/test_eth_types.nim b/tests/common/test_eth_types.nim
index 6e04628c..fe8f1ab6 100644
--- a/tests/common/test_eth_types.nim
+++ b/tests/common/test_eth_types.nim
@@ -4,7 +4,9 @@ import
   unittest2,
   nimcrypto/hash,
   serialization/testing/generic_suite,
-  ../../eth/common/[eth_types, eth_types_json_serialization]
+  ../../eth/common/[eth_types, eth_types_json_serialization],
+  ../../eth/common/eth_types_rlp,
+  ../../eth/rlp
 
 func `==`*(lhs, rhs: BlockHashOrNumber): bool =
   if lhs.isHash != rhs.isHash:
@@ -15,6 +17,9 @@ func `==`*(lhs, rhs: BlockHashOrNumber): bool =
   else:
     lhs.number == rhs.number
 
+const
+  testHash = Hash256.fromHex "0x7a64245f7f95164f6176d90bd4903dbdd3e5433d555dd1385e81787f9672c588"
+
 suite "BlockHashOrNumber":
   test "construction":
     expect ValueError:
@@ -53,8 +58,20 @@ suite "BlockHashOrNumber":
                        "\"1209231231\""
 
   test "EIP-4399 prevRandao field":
-    let hash = Hash256.fromHex "0x7a64245f7f95164f6176d90bd4903dbdd3e5433d555dd1385e81787f9672c588"
     var blk: BlockHeader
-    blk.prevRandao = hash
+    blk.prevRandao = testHash
     let res = blk.prevRandao
-    check hash == res
+    check testHash == res
+
+  test "EIP-4788 parentBeaconBlockRoot field":
+    let header = BlockHeader(
+      fee: some(0.u256),
+      withdrawalsRoot: some(testHash),
+      blobGasUsed: some(1'u64),
+      excessBlobGas: some(2'u64),
+      parentBeaconBlockRoot: some(testHash),
+    )
+    let rlpBytes = rlp.encode(header)
+    let dh = rlp.decode(rlpBytes, BlockHeader)
+    check dh.parentBeaconBlockRoot.isSome
+    check dh.parentBeaconBlockRoot.get == testHash