[Cleanup] Initial documentation improvements and code cleanup

fuzz_test.go

@@ -0,0 +1,103 @@
+package smt
+
+import (
+	"bytes"
+	"crypto/sha256"
+	"encoding/binary"
+	"math"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func FuzzSMT(f *testing.F) {
+	seeds := [][]byte{
+		[]byte(""),
+		[]byte("foo"),
+		{1, 2, 3, 4},
+		[]byte("\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"),
+		nil,
+	}
+	for _, s := range seeds {
+		f.Add(s)
+	}
+	f.Fuzz(func(t *testing.T, input []byte) {
+		t.Log(input)
+		smn := NewSimpleMap()
+		tree := NewSparseMerkleTree(smn, sha256.New())
+
+		r := bytes.NewReader(input)
+		var keys [][]byte
+		key := func() []byte {
+			if readByte(r) < math.MaxUint8/2 {
+				k := make([]byte, readByte(r)/2)
+				if _, err := r.Read(k); err != nil {
+					return nil
+				}
+				keys = append(keys, k)
+				return k
+			}
+
+			if len(keys) == 0 {
+				return nil
+			}
+
+			return keys[int(readByte(r))%len(keys)]
+		}
+
+		for i := 0; r.Len() != 0; i++ {
+			b, err := r.ReadByte()
+			if err != nil {
+				continue
+			}
+
+			op := op(int(b) % int(Noop))
+			switch op {
+			case Get:
+				_, err := tree.Get(key())
+				if err != nil {
+					require.ErrorIsf(t, err, ErrKeyNotPresent, "unknown error occured while getting")
+				}
+			case Update:
+				value := make([]byte, 32)
+				binary.BigEndian.PutUint64(value, uint64(i))
+				err := tree.Update(key(), value)
+				if err != nil {
+					require.ErrorIsf(t, err, ErrKeyNotPresent, "unknown error occured while updating")
+				}
+			case Delete:
+				err := tree.Delete(key())
+				if err != nil {
+					require.ErrorIsf(t, err, ErrKeyNotPresent, "unknown error occured while deleting")
+				}
+			case Prove:
+				_, err := tree.Prove(key())
+				if err != nil {
+					require.ErrorIsf(t, err, ErrKeyNotPresent, "unknown error occured while proving")
+				}
+			}
+
+			newRoot := tree.Root()
+			require.Greater(t, len(newRoot), 0, "new root is empty while err is nil")
+		}
+	})
+}
+
+// Fuzzing helpers
+type op int
+
+const (
+	Get op = iota
+	Update
+	Delete
+	Prove
+	Noop
+)
+
+func readByte(r *bytes.Reader) byte {
+	b, err := r.ReadByte()
+	if err != nil {
+		return 0
+	}
+	return b
+}

smt_testutil.go

@@ -35,7 +35,7 @@ func (smt *SMTWithStorage) Delete(key []byte) error {
 
 // Get gets the value of a key from the tree.
 func (smt *SMTWithStorage) GetValue(key []byte) ([]byte, error) {
-	valueHash, err := smt.SMT.Get(key)
+	valueHash, err := smt.Get(key)
 	if err != nil {
 		return nil, err
 	}