From 67a91c72d60763407124c5530ea807a746398fc2 Mon Sep 17 00:00:00 2001
From: Matthew Slipper <me@matthewslipper.com>
Date: Thu, 20 Oct 2022 12:03:10 -0600
Subject: [PATCH 1/2] Update test suite to add historical rpc

---
 eth/tracers/api_test.go | 1 +
 1 file changed, 1 insertion(+)

diff --git a/eth/tracers/api_test.go b/eth/tracers/api_test.go
index a96f3efdad..0de409f797 100644
--- a/eth/tracers/api_test.go
+++ b/eth/tracers/api_test.go
@@ -23,6 +23,7 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
+	"github.com/ethereum/go-ethereum/node"
 	"math/big"
 	"net"
 	"net/http"

From 0e50c59da4dbd7a74bf1e59e13788dc28eac6648 Mon Sep 17 00:00:00 2001
From: Maurelian <maurelian@protonmail.ch>
Date: Tue, 25 Oct 2022 13:32:05 -0400
Subject: [PATCH 2/2] Add historical endpoint to TraceCall

Update tests to handle ethereum.NotFound
---
 eth/tracers/api.go      | 23 +++++++++++++++++
 eth/tracers/api_test.go | 55 ++++++++++++++++++++++++++++++++++++++---
 2 files changed, 74 insertions(+), 4 deletions(-)

diff --git a/eth/tracers/api.go b/eth/tracers/api.go
index 8d1cb264ab..ac313f8205 100644
--- a/eth/tracers/api.go
+++ b/eth/tracers/api.go
@@ -860,6 +860,29 @@ func (api *API) TraceCall(ctx context.Context, args ethapi.TransactionArgs, bloc
 	} else {
 		return nil, errors.New("invalid arguments; neither block nor hash specified")
 	}
+
+	// If block still holds no value, but we have an error, then one of the two previous conditions
+	// was entered, meaning:
+	// 1. blockNrOrHash has either a valid block or hash
+	// 2. we don't have that block locally
+	if block == nil && errors.Is(err, ethereum.NotFound) && api.backend.HistoricalRPCService() != nil {
+		var histResult json.RawMessage
+		err = api.backend.HistoricalRPCService().CallContext(ctx, &histResult, "debug_traceCall", args, blockNrOrHash, config)
+		if err != nil && err.Error() == "not found" {
+			// Not found locally or in history. We need to return different errors based on the input
+			// in order match geth's native behavior
+			if hash, ok := blockNrOrHash.Hash(); ok {
+				return nil, fmt.Errorf("block %s %w", hash, ethereum.NotFound)
+			} else if number, ok := blockNrOrHash.Number(); ok {
+				return nil, fmt.Errorf("block #%d %w", number, ethereum.NotFound)
+			}
+		} else if err != nil {
+			return nil, fmt.Errorf("error querying historical RPC: %w", err)
+		}
+
+		return histResult, nil
+	}
+
 	if err != nil {
 		return nil, err
 	}
diff --git a/eth/tracers/api_test.go b/eth/tracers/api_test.go
index 0de409f797..9ed538414f 100644
--- a/eth/tracers/api_test.go
+++ b/eth/tracers/api_test.go
@@ -23,7 +23,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"github.com/ethereum/go-ethereum/node"
 	"math/big"
 	"net"
 	"net/http"
@@ -52,8 +51,9 @@ import (
 )
 
 var (
-	errStateNotFound = errors.New("state not found")
-	errBlockNotFound = errors.New("block not found")
+	errStateNotFound   = errors.New("state not found")
+	errBlockNotFound   = errors.New("block not found")
+	errFailingUpstream = errors.New("historical query failed")
 )
 
 type mockHistoricalBackend struct{}
@@ -85,6 +85,17 @@ func (m *mockHistoricalBackend) TraceTransaction(ctx context.Context, hash commo
 	return nil, ethereum.NotFound
 }
 
+func (m *mockHistoricalBackend) TraceCall(ctx context.Context, args ethapi.TransactionArgs, blockNrOrHash rpc.BlockNumberOrHash, config *TraceCallConfig) (interface{}, error) {
+	num, ok := blockNrOrHash.Number()
+	if ok && num == 777 {
+		return json.RawMessage(`{"gas":21000,"failed":false,"returnValue":"777","structLogs":[]}`), nil
+	}
+	if ok && num == 12345 {
+		return nil, errFailingUpstream
+	}
+	return nil, ethereum.NotFound
+}
+
 func newMockHistoricalBackend(t *testing.T) string {
 	s := rpc.NewServer()
 	err := node.RegisterApis([]rpc.API{
@@ -324,6 +335,40 @@ func TestTraceCall(t *testing.T) {
 			expectErr: fmt.Errorf("block #%d %w", genBlocks+1, ethereum.NotFound),
 			//expect:    nil,
 		},
+		// Optimism: Trace block on the historical chain
+		{
+			blockNumber: rpc.BlockNumber(777),
+			call: ethapi.TransactionArgs{
+				From:  &accounts[0].addr,
+				To:    &accounts[1].addr,
+				Value: (*hexutil.Big)(big.NewInt(1000)),
+			},
+			config:    nil,
+			expectErr: nil,
+			expect:    `{"gas":21000,"failed":false,"returnValue":"777","structLogs":[]}`,
+		},
+		// Optimism: Trace block that doesn't exist anywhere
+		{
+			blockNumber: rpc.BlockNumber(39347856),
+			call: ethapi.TransactionArgs{
+				From:  &accounts[0].addr,
+				To:    &accounts[1].addr,
+				Value: (*hexutil.Big)(big.NewInt(1000)),
+			},
+			config:    nil,
+			expectErr: fmt.Errorf("block #39347856 %w", ethereum.NotFound),
+		},
+		// Optimism: Trace block with failing historical upstream
+		{
+			blockNumber: rpc.BlockNumber(12345),
+			call: ethapi.TransactionArgs{
+				From:  &accounts[0].addr,
+				To:    &accounts[1].addr,
+				Value: (*hexutil.Big)(big.NewInt(1000)),
+			},
+			config:    nil,
+			expectErr: fmt.Errorf("error querying historical RPC: %w", errFailingUpstream),
+		},
 		// Standard JSON trace upon the latest block
 		{
 			blockNumber: rpc.LatestBlockNumber,
@@ -369,8 +414,10 @@ func TestTraceCall(t *testing.T) {
 				t.Errorf("test %d: expect error %v, got nothing", i, testspec.expectErr)
 				continue
 			}
+			// Have to introduce this diff to reflect the fact that errors
+			// from the upstream will not preserve pointer equality.
 			if err.Error() != testspec.expectErr.Error() {
-				t.Errorf("test %d: error mismatch, want %v, git %v", i, testspec.expectErr, err)
+				t.Errorf("test %d: error mismatch, want %v, got %v", i, testspec.expectErr, err)
 			}
 		} else {
 			if err != nil {