From ae33dce5af18421c3f3cdacd021bd06fe952cf04 Mon Sep 17 00:00:00 2001
From: Roy Crihfield <roy@manteia.ltd>
Date: Wed, 6 Sep 2023 20:13:32 +0800
Subject: [PATCH] add diff iterator comparison on mainnet data

---
 go.mod                 |  2 ++
 go.sum                 |  2 ++
 test_helpers/util.go   |  3 ++-
 utils/iterator_test.go | 59 ++++++++++++++++++++++++++++++++++++++++--
 4 files changed, 63 insertions(+), 3 deletions(-)

diff --git a/go.mod b/go.mod
index 767ce44..e18b6b2 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module github.com/cerc-io/plugeth-statediff
 go 1.19
 
 require (
+	github.com/cerc-io/eth-test-data v0.1.0
 	github.com/ethereum/go-ethereum v1.11.6
 	github.com/georgysavva/scany v0.2.9
 	github.com/golang/mock v1.6.0
@@ -123,6 +124,7 @@ require (
 )
 
 replace (
+	github.com/cerc-io/eth-test-data => git.vdb.to/cerc-io/eth-test-data v0.1.1
 	github.com/ethereum/go-ethereum => git.vdb.to/cerc-io/plugeth v0.0.0-20230808125822-691dc334fab1
 	github.com/openrelayxyz/plugeth-utils => git.vdb.to/cerc-io/plugeth-utils v0.0.0-20230706160122-cd41de354c46
 )
diff --git a/go.sum b/go.sum
index 8c7bd92..993301d 100644
--- a/go.sum
+++ b/go.sum
@@ -1,3 +1,5 @@
+git.vdb.to/cerc-io/eth-test-data v0.1.1 h1:J0dO1ozKdimMgvxO1rubTgLrOp7vljRm1g0OfTaUp7k=
+git.vdb.to/cerc-io/eth-test-data v0.1.1/go.mod h1:8BypMWF/Xz4CGSn3ad4yXz0deCFFk1DxujOCU8+ydGE=
 git.vdb.to/cerc-io/plugeth v0.0.0-20230808125822-691dc334fab1 h1:KLjxHwp9Zp7xhECccmJS00RiL+VwTuUGLU7qeIctg8g=
 git.vdb.to/cerc-io/plugeth v0.0.0-20230808125822-691dc334fab1/go.mod h1:cYXZu70+6xmDgIgrTD81GPasv16piiAFJnKyAbwVPMU=
 git.vdb.to/cerc-io/plugeth-utils v0.0.0-20230706160122-cd41de354c46 h1:KYcbbne/RXd7AuxbUd/3hgk1jPN+33k2CKiNsUsMCC0=
diff --git a/test_helpers/util.go b/test_helpers/util.go
index 30c7530..95ccfdf 100644
--- a/test_helpers/util.go
+++ b/test_helpers/util.go
@@ -6,7 +6,8 @@ import (
 	"github.com/cerc-io/plugeth-statediff/utils/log"
 )
 
-// The geth sync logs are noisy, it can be useful to silence them
+// SilenceLogs silences the geth logs and sets the plugin test log level to "warning"
+// The geth sync logs are noisy, so it can be nice to silence them.
 func SilenceLogs() {
 	geth_log.Root().SetHandler(geth_log.DiscardHandler())
 	log.TestLogger.SetLevel(2)
diff --git a/utils/iterator_test.go b/utils/iterator_test.go
index 92c461e..3a97939 100644
--- a/utils/iterator_test.go
+++ b/utils/iterator_test.go
@@ -3,11 +3,17 @@ package utils_test
 import (
 	"testing"
 
-	"github.com/cerc-io/plugeth-statediff/utils"
+	"github.com/cerc-io/eth-test-data/fixture/mainnet"
+	"github.com/ethereum/go-ethereum/consensus/ethash"
+	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/rawdb"
+	"github.com/ethereum/go-ethereum/core/vm"
 	"github.com/ethereum/go-ethereum/trie"
-
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/cerc-io/plugeth-statediff/test_helpers"
+	"github.com/cerc-io/plugeth-statediff/utils"
 )
 
 type kvs struct{ k, v string }
@@ -169,3 +175,52 @@ func TestSymmetricDifferenceIterator(t *testing.T) {
 	assert.Equal(t, expectedDeletions, deletions)
 	assert.Equal(t, expectedCreations, creations)
 }
+
+// compare the paths traversed by the geth difference iterator and symmetric difference iterator
+// within a sample of mainnet data.
+func TestCompareDifferenceIterators(t *testing.T) {
+	test_helpers.SilenceLogs()
+
+	db := rawdb.NewMemoryDatabase()
+	core.DefaultGenesisBlock().MustCommit(db)
+	blocks := mainnet.LoadBlocks(2)
+	chain, _ := core.NewBlockChain(db, nil, nil, nil, ethash.NewFaker(), vm.Config{}, nil, nil)
+	_, err := chain.InsertChain(blocks[1:])
+	if err != nil {
+		t.Fatal(err)
+	}
+	treeA, err := chain.StateCache().OpenTrie(blocks[1].Root())
+	if err != nil {
+		t.Fatal(err)
+	}
+	treeB, err := chain.StateCache().OpenTrie(blocks[2].Root())
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// collect the paths of nodes exclusive to A and B separately, then make sure the symmetric
+	// iterator produces the same sets
+	var pathsA, pathsB [][]byte
+	itBonly, _ := trie.NewDifferenceIterator(treeA.NodeIterator(nil), treeB.NodeIterator(nil))
+	for itBonly.Next(true) {
+		pathsB = append(pathsB, itBonly.Path())
+	}
+	itAonly, _ := trie.NewDifferenceIterator(treeB.NodeIterator(nil), treeA.NodeIterator(nil))
+	for itAonly.Next(true) {
+		pathsA = append(pathsA, itAonly.Path())
+	}
+
+	itSym, _ := utils.NewSymmetricDifferenceIterator(treeA.NodeIterator(nil), treeB.NodeIterator(nil))
+	var idxA, idxB int
+	for itSym.Next(true) {
+		if itSym.FromA() {
+			require.Equal(t, pathsA[idxA], itSym.Path())
+			idxA++
+		} else {
+			require.Equal(t, pathsB[idxB], itSym.Path())
+			idxB++
+		}
+	}
+	require.Equal(t, len(pathsA), idxA)
+	require.Equal(t, len(pathsB), idxB)
+}