添加掩码格式

ip_range/mask_bits_test.go

@@ -0,0 +1,26 @@
+package iprange
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMaskToBits(t *testing.T) {
+
+	masks := []struct {
+		mask   string
+		expect int
+	}{
+		{"255.255.255.0", 24},
+		{"255.255.248.0", 21},
+		{"255.255.192.0", 18},
+		{"255.255.255.192", 26},
+	}
+
+	for _, m := range masks {
+		bits := MaskToBits(m.mask)
+		assert.Equal(t, m.expect, bits, fmt.Sprintf("IP:%s 掩码位数错误。", m.mask))
+	}
+}