meter: complete interface

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

meter/meter_test.go

@@ -11,4 +11,53 @@ func TestNoopMeter(t *testing.T) {
 	assert.NotNil(t, meter)
 	assert.Equal(t, "/noop", meter.Options().Path)
 	assert.Implements(t, new(Meter), meter)
+
+	cnt := meter.Counter("counter", Label("server", "noop"))
+	cnt.Inc()
+
+}
+
+func TestLabels(t *testing.T) {
+	var ls Labels
+	ls.keys = []string{"type", "server"}
+	ls.vals = []string{"noop", "http"}
+
+	ls.Sort()
+
+	if ls.keys[0] != "server" || ls.vals[0] != "http" {
+		t.Fatalf("sort error: %v", ls)
+	}
+}
+
+func TestLabelsAppend(t *testing.T) {
+	var ls Labels
+	ls.keys = []string{"type", "server"}
+	ls.vals = []string{"noop", "http"}
+
+	var nls Labels
+	nls.keys = []string{"registry"}
+	nls.vals = []string{"gossip"}
+	ls = ls.Append(nls)
+
+	ls.Sort()
+
+	if ls.keys[0] != "registry" || ls.vals[0] != "gossip" {
+		t.Fatalf("append error: %v", ls)
+	}
+}
+
+func TestIterator(t *testing.T) {
+	var ls Labels
+	ls.keys = []string{"type", "server", "registry"}
+	ls.vals = []string{"noop", "http", "gossip"}
+
+	iter := ls.Iter()
+	var k, v string
+	cnt := 0
+	for iter.Next(&k, &v) {
+		if cnt == 1 && (k != "server" || v != "http") {
+			t.Fatalf("iter error: %s != %s || %s != %s", k, "server", v, "http")
+		}
+		cnt++
+	}
 }