feat: update iterator package

iterator/iterator_test.go

@@ -1,4 +1,4 @@
-// Copyright 2021 dudaodong@gmail.com. All rights resulterved.
+// Copyright 2022 dudaodong@gmail.com. All rights resulterved.
 // Use of this source code is governed by MIT license
 
 // Package iterator implements some feature of C++ STL iterators
@@ -13,27 +13,38 @@ import (
 func TestSliceIterator(t *testing.T) {
 	assert := internal.NewAssert(t, "TestSliceIterator")
 
-	t.Run("slice iterator has next", func(t *testing.T) {
-		iter := FromSlice([]int{1, 2, 3, 4})
+	// HashNext
+	t.Run("slice iterator HasNext: ", func(t *testing.T) {
+		iter1 := FromSlice([]int{1, 2, 3, 4})
 		for {
-			item, _ := iter.Next()
-			if item < 4 {
-				assert.Equal(true, iter.HasNext())
-			} else {
-				assert.Equal(false, iter.HasNext())
+			item, _ := iter1.Next()
+
+			if item == 4 {
+				assert.Equal(false, iter1.HasNext())
 				break
+			} else {
+				assert.Equal(true, iter1.HasNext())
 			}
 		}
+
+		iter2 := FromSlice([]int{})
+		assert.Equal(false, iter2.HasNext())
 	})
 
-	t.Run("slice iterator next", func(t *testing.T) {
-		iter := FromSlice([]int{1, 2, 3, 4})
+	//Next
+	t.Run("slice iterator Next: ", func(t *testing.T) {
+		iter1 := FromSlice([]int{1, 2, 3, 4})
 		for i := 0; i < 4; i++ {
-			item, ok := iter.Next()
+			item, ok := iter1.Next()
 			if !ok {
 				break
 			}
 			assert.Equal(i+1, item)
 		}
+
+		iter2 := FromSlice([]int{})
+		_, ok := iter2.Next()
+		assert.Equal(false, ok)
 	})
+
 }