From a9d4fffc97df484d20ec5ed680480e7b80473712 Mon Sep 17 00:00:00 2001
From: Daniel Liu <139250065@qq.com>
Date: Thu, 17 Jul 2025 17:55:19 +0800
Subject: [PATCH] trie: move fuzzers into native packages #28467 (#1239)

---
 trie/trie_test.go | 65 +++++++++++++++++++++++++++++++++++------------
 1 file changed, 49 insertions(+), 16 deletions(-)

diff --git a/trie/trie_test.go b/trie/trie_test.go
index 8ae4db0716..e6d539911d 100644
--- a/trie/trie_test.go
+++ b/trie/trie_test.go
@@ -23,6 +23,7 @@ import (
 	"errors"
 	"fmt"
 	"hash"
+	"io"
 	"math/big"
 	"math/rand"
 	"reflect"
@@ -292,8 +293,9 @@ func TestRandomCases(t *testing.T) {
 		{op: 1, key: common.Hex2Bytes("980c393656413a15c8da01978ed9f89feb80b502f58f2d640e3a2f5f7a99a7018f1b573befd92053ac6f78fca4a87268"), value: common.Hex2Bytes("")}, // step 24
 		{op: 1, key: common.Hex2Bytes("fd"), value: common.Hex2Bytes("")},                                                                                               // step 25
 	}
-	runRandTest(rt)
-
+	if err := runRandTest(rt); err != nil {
+		t.Fatal(err)
+	}
 }
 
 // randTest performs random trie operations.
@@ -319,36 +321,53 @@ const (
 )
 
 func (randTest) Generate(r *rand.Rand, size int) reflect.Value {
+	var finishedFn = func() bool {
+		size--
+		return size > 0
+	}
+	return reflect.ValueOf(generateSteps(finishedFn, r))
+}
+
+func generateSteps(finished func() bool, r io.Reader) randTest {
 	var allKeys [][]byte
+	var one = []byte{0}
 	genKey := func() []byte {
-		if len(allKeys) < 2 || r.Intn(100) < 10 {
+		r.Read(one)
+		if len(allKeys) < 2 || one[0]%100 > 90 {
 			// new key
-			key := make([]byte, r.Intn(50))
+			size := one[0] % 50
+			key := make([]byte, size)
 			r.Read(key)
 			allKeys = append(allKeys, key)
 			return key
 		}
 		// use existing key
-		return allKeys[r.Intn(len(allKeys))]
+		idx := int(one[0]) % len(allKeys)
+		return allKeys[idx]
 	}
-
 	var steps randTest
-	for i := 0; i < size; i++ {
-		step := randTestStep{op: r.Intn(opMax)}
+	for !finished() {
+		r.Read(one)
+		step := randTestStep{op: int(one[0]) % opMax}
 		switch step.op {
 		case opUpdate:
 			step.key = genKey()
 			step.value = make([]byte, 8)
-			binary.BigEndian.PutUint64(step.value, uint64(i))
+			binary.BigEndian.PutUint64(step.value, uint64(len(steps)))
 		case opGet, opDelete:
 			step.key = genKey()
 		}
 		steps = append(steps, step)
 	}
-	return reflect.ValueOf(steps)
+	return steps
 }
 
-func runRandTest(rt randTest) bool {
+// runRandTestBool coerces error to boolean, for use in quick.Check
+func runRandTestBool(rt randTest) bool {
+	return runRandTest(rt) == nil
+}
+
+func runRandTest(rt randTest) error {
 	triedb := NewDatabase(memorydb.New())
 
 	tr, _ := New(common.Hash{}, triedb)
@@ -378,12 +397,12 @@ func runRandTest(rt randTest) bool {
 			hash, err := tr.Commit(nil)
 			if err != nil {
 				rt[i].err = err
-				return false
+				return err
 			}
 			newtr, err := New(hash, triedb)
 			if err != nil {
 				rt[i].err = err
-				return false
+				return err
 			}
 			tr = newtr
 		case opItercheckhash:
@@ -398,14 +417,14 @@ func runRandTest(rt randTest) bool {
 		}
 		// Abort the test on error.
 		if rt[i].err != nil {
-			return false
+			return rt[i].err
 		}
 	}
-	return true
+	return nil
 }
 
 func TestRandom(t *testing.T) {
-	if err := quick.Check(runRandTest, nil); err != nil {
+	if err := quick.Check(runRandTestBool, nil); err != nil {
 		if cerr, ok := err.(*quick.CheckError); ok {
 			t.Fatalf("random test iteration %d failed: %s", cerr.Count, spew.Sdump(cerr.In))
 		}
@@ -841,3 +860,17 @@ func TestDecodeNode(t *testing.T) {
 		decodeNode(hash, elems)
 	}
 }
+
+func FuzzTrie(f *testing.F) {
+	f.Fuzz(func(t *testing.T, data []byte) {
+		var steps = 500
+		var input = bytes.NewReader(data)
+		var finishedFn = func() bool {
+			steps--
+			return steps < 0 || input.Len() == 0
+		}
+		if err := runRandTest(generateSteps(finishedFn, input)); err != nil {
+			t.Fatal(err)
+		}
+	})
+}