diff --git a/common/alloc/buffer_test.go b/common/alloc/buffer_test.go
new file mode 100644
index 000000000..ab3da3c4f
--- /dev/null
+++ b/common/alloc/buffer_test.go
@@ -0,0 +1,33 @@
+package alloc
+
+import (
+	"testing"
+
+	"github.com/v2ray/v2ray-core/testing/unit"
+)
+
+func TestBufferClear(t *testing.T) {
+	assert := unit.Assert(t)
+
+	buffer := NewBuffer().Clear()
+	defer buffer.Release()
+
+	payload := "Bytes"
+	buffer.Append([]byte(payload))
+	assert.Int(buffer.Len()).Equals(len(payload))
+
+	buffer.Clear()
+	assert.Int(buffer.Len()).Equals(0)
+}
+
+func TestBufferIsFull(t *testing.T) {
+	assert := unit.Assert(t)
+
+	buffer := NewBuffer()
+	defer buffer.Release()
+
+	assert.Bool(buffer.IsFull()).IsTrue()
+
+	buffer.Clear()
+	assert.Bool(buffer.IsFull()).IsFalse()
+}