Add tests

trie.go

@@ -144,7 +144,7 @@ func (n *node) add(key, value []byte) {
 
 func traversePrint(n *node, prefix string) {
 	if n.key != nil {
-		fmt.Printf("%s %s\n", prefix, formatBinary(n.key))
+		fmt.Printf("%s %s %v\n", prefix, formatBinary(n.key), n.value)
 		return
 	}
 	if n.left != nil {

trie_test.go

@@ -3,6 +3,7 @@ package trie_test
 import (
 	"bytes"
 	"crypto/rand"
+	"fmt"
 	"testing"
 
 	"github.com/lukesolo/merkle-trie"
@@ -16,8 +17,89 @@ func ExampleLowestNumbers() {
 	tree.Print()
 
 	// Output:
-	// 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
-	// 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001
+	// 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 []
+	// 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001 []
+}
+
+func ExampleEmptyMerkleTrieHash() {
+	tree := trie.NewMerkleTrie()
+	fmt.Printf("%x", tree.Hash())
+
+	// Output:
+	// e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
+}
+
+func ExampleSetHighBit() {
+	tree := trie.NewMerkleTrie()
+	tree.Add(zero(), nil)
+	tree.Add(highBit(), nil)
+
+	tree.Print()
+
+	// Output:
+	// 0 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 []
+	// 1 1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 []
+}
+
+func ExampleLowestAndHighestNumbers() {
+	tree := trie.NewMerkleTrie()
+	tree.Add(max(), nil)
+	tree.Add(zero(), nil)
+
+	tree.Print()
+
+	// Output:
+	// 0 0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000 []
+	// 1 1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111 []
+}
+
+func TestChangeValue(t *testing.T) {
+	tree := trie.NewMerkleTrie()
+
+	tree.Add([]byte{0, 0, 0, 0}, []byte{0})
+	tree.Add([]byte{255, 255, 0, 128}, []byte{1})
+	tree.Add([]byte{255, 255, 0, 0}, []byte{2})
+	tree.Add([]byte{127, 255, 0, 1}, []byte{3})
+	tree.Add([]byte{127, 255, 0, 128}, []byte{4})
+
+	hash1 := tree.Hash()
+
+	tree.Add([]byte{127, 255, 0, 1}, []byte{5})
+	hash2 := tree.Hash()
+
+	if bytes.Equal(hash1, hash2) {
+		t.Error("Change value, but hash still the same")
+	}
+
+	tree.Add([]byte{127, 255, 0, 1}, []byte{3})
+	hash3 := tree.Hash()
+
+	if !bytes.Equal(hash1, hash3) {
+		t.Error("Restore value, but hash doesn't equal the old one")
+	}
+
+}
+
+func ExampleMerkleTrie_MaxDepth() {
+	tree := trie.NewMerkleTrie()
+	fmt.Println(tree.MaxDepth())
+
+	tree.Add([]byte{0, 0, 0, 0}, []byte{0})
+	tree.Add([]byte{255, 255, 0, 128}, []byte{1})
+	fmt.Println(tree.MaxDepth())
+
+	tree.Add([]byte{0, 255, 0, 1}, []byte{2})
+	fmt.Println(tree.MaxDepth())
+
+	tree.Add([]byte{127, 255, 0, 1}, []byte{3})
+	tree.Add([]byte{127, 255, 0, 128}, []byte{4})
+	fmt.Println(tree.MaxDepth())
+
+	// Output
+	// 0
+	// 1
+	// 9
+	// 25
 }
 
 func TestIgnoreOrder(t *testing.T) {
@@ -55,3 +137,17 @@ func one() []byte {
 	one[31] = 1
 	return one
 }
+
+func highBit() []byte {
+	res := make([]byte, 32, 32)
+	res[0] = 128
+	return res
+}
+
+func max() []byte {
+	res := make([]byte, 32, 32)
+	for i := range res {
+		res[i] = 255
+	}
+	return res
+}