diff --git a/id_test.go b/id_test.go
index f68db5042c..3cb247fe09 100644
--- a/id_test.go
+++ b/id_test.go
@@ -1,6 +1,7 @@
 package platform
 
 import (
+	"bytes"
 	"reflect"
 	"testing"
 )
@@ -36,3 +37,49 @@ func TestIDFromString(t *testing.T) {
 		})
 	}
 }
+
+func TestDecodeFromString(t *testing.T) {
+	var id1 ID
+	err := id1.DecodeFromString("020f755c3c082000")
+	if err != nil {
+		t.Errorf(err.Error())
+	}
+	want1 := []byte{48, 50, 48, 102, 55, 53, 53, 99, 51, 99, 48, 56, 50, 48, 48, 48}
+	byte1 := id1.Encode()
+	if !bytes.Equal(want1, byte1) {
+		t.Errorf("encoding error")
+	}
+}
+
+func TestDecodeFromShorterString(t *testing.T) {
+	var id1 ID
+	err := id1.DecodeFromString("020f75")
+	if err != nil {
+		t.Errorf(err.Error())
+	}
+	want1 := []byte{48, 50, 48, 102, 55, 53, 48, 48, 48, 48, 48, 48, 48, 48, 48, 48}
+	byte1 := id1.Encode()
+	if !bytes.Equal(want1, byte1) {
+		t.Errorf("encoding error")
+	}
+
+	if id1.String() != "020f750000000000" {
+		t.Errorf("wrong id")
+	}
+}
+
+func TestDecodeFromLongerString(t *testing.T) {
+	var id1 ID
+	err := id1.DecodeFromString("020f755c3c082000aaa")
+	if err != nil {
+		t.Errorf(err.Error())
+	}
+	want1 := []byte{48, 50, 48, 102, 55, 53, 53, 99, 51, 99, 48, 56, 50, 48, 48, 48}
+	byte1 := id1.Encode()
+	if !bytes.Equal(want1, byte1) {
+		t.Errorf("encoding error")
+	}
+}
+
+// todo
+// func TestDecodeFromEmptyString(t *testing.T) {}