From d8c6ae054c8e120c72d20eeac805f1b95e5802a2 Mon Sep 17 00:00:00 2001
From: Adrian Sutton <adrian@oplabs.co>
Date: Wed, 25 Oct 2023 23:52:42 +1000
Subject: [PATCH] rpc: use correct stringer-method for serializing
 BlockNumberOrHash (#28358)

The String() version of BlockNumberOrHash uses decimal for all block numbers, including negative ones used to indicate labels. Switch to using BlockNumber.String() which encodes it correctly for use in the JSON-RPC API.
---
 rpc/types.go      |  3 +--
 rpc/types_test.go | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/rpc/types.go b/rpc/types.go
index 34a1451de..f88c37c59 100644
--- a/rpc/types.go
+++ b/rpc/types.go
@@ -21,7 +21,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"math"
-	"strconv"
 	"strings"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -221,7 +220,7 @@ func (bnh *BlockNumberOrHash) Number() (BlockNumber, bool) {
 
 func (bnh *BlockNumberOrHash) String() string {
 	if bnh.BlockNumber != nil {
-		return strconv.Itoa(int(*bnh.BlockNumber))
+		return bnh.BlockNumber.String()
 	}
 	if bnh.BlockHash != nil {
 		return bnh.BlockHash.String()
diff --git a/rpc/types_test.go b/rpc/types_test.go
index f110dee7c..617f441d9 100644
--- a/rpc/types_test.go
+++ b/rpc/types_test.go
@@ -153,3 +153,24 @@ func TestBlockNumberOrHash_WithNumber_MarshalAndUnmarshal(t *testing.T) {
 		})
 	}
 }
+
+func TestBlockNumberOrHash_StringAndUnmarshal(t *testing.T) {
+	tests := []BlockNumberOrHash{
+		BlockNumberOrHashWithNumber(math.MaxInt64),
+		BlockNumberOrHashWithNumber(PendingBlockNumber),
+		BlockNumberOrHashWithNumber(LatestBlockNumber),
+		BlockNumberOrHashWithNumber(EarliestBlockNumber),
+		BlockNumberOrHashWithNumber(32),
+		BlockNumberOrHashWithHash(common.Hash{0xaa}, false),
+	}
+	for _, want := range tests {
+		marshalled, _ := json.Marshal(want.String())
+		var have BlockNumberOrHash
+		if err := json.Unmarshal(marshalled, &have); err != nil {
+			t.Fatalf("cannot unmarshal (%v): %v", string(marshalled), err)
+		}
+		if !reflect.DeepEqual(want, have) {
+			t.Fatalf("wrong result: have %v, want %v", have, want)
+		}
+	}
+}