add unit test TestLabels_String for pkg/labels/labels.go
@@ -19,6 +19,39 @@ import (
"github.com/prometheus/prometheus/util/testutil"
)
+func TestLabels_String(t *testing.T) {
+ cases := []struct {
+ lables Labels
+ expected string
+ }{
+ {
+ lables: Labels{
+ {
+ Name: "t1",
+ Value: "t1",
+ },
+ {
+ Name: "t2",
+ Value: "t2",
+ },
+ },
+ expected: "{t1=\"t1\", t2=\"t2\"}",
+ },
+ {
+ lables: Labels{},
+ expected: "{}",
+ },
+ {
+ lables: nil,
+ expected: "{}",
+ },
+ }
+ for _, c := range cases {
+ str := c.lables.String()
+ testutil.Equals(t, c.expected, str)
+ }
+}
+
func TestLabels_MatchLabels(t *testing.T) {
labels := Labels{
{
