test(metanode): add free_list.go unit test

Signed-off-by: jjyaoao <jjyaoao@126.com>

metanode/free_list_test.go

@@ -0,0 +1,38 @@
+package metanode
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestFreeList(t *testing.T) {
+	fl := newFreeList()
+
+	require.Equal(t, 0, fl.Len())
+
+	// Test Push
+	fl.Push(1)
+	require.Equal(t, 1, fl.Len())
+
+	fl.Push(2)
+	require.Equal(t, 2, fl.Len())
+
+	// Test Pop
+	require.Equal(t, uint64(1), fl.Pop())
+	require.Equal(t, 1, fl.Len())
+
+	require.Equal(t, uint64(2), fl.Pop())
+	require.Equal(t, 0, fl.Len())
+
+	// Test Remove
+	fl.Push(3)
+	fl.Push(4)
+	require.Equal(t, 2, fl.Len())
+
+	fl.Remove(3)
+	require.Equal(t, 1, fl.Len())
+
+	require.Equal(t, uint64(4), fl.Pop())
+	require.Equal(t, 0, fl.Len())
+}