Function TestWrapCollector

prometheus/wrap_test.go:349–468

(t *testing.T)

}

func TestWrapCollector(t *testing.T) {
	t.Run("can be registered and un-registered", func(t *testing.T) {
		inner := NewPedanticRegistry()
		g := NewGauge(GaugeOpts{Name: "testing"})
		g.Set(42)
		err := inner.Register(g)
		if err != nil {
			t.Fatal("registering failed:", err)
		}

		wrappedWithLabels := WrapCollectorWith(Labels{"lbl": "1"}, inner)
		wrappedWithPrefix := WrapCollectorWithPrefix("prefix", inner)
		reg := NewPedanticRegistry()
		err = reg.Register(wrappedWithLabels)
		if err != nil {
			t.Fatal("registering failed:", err)
		}
		err = reg.Register(wrappedWithPrefix)
		if err != nil {
			t.Fatal("registering failed:", err)
		}

		gathered, err := reg.Gather()
		if err != nil {
			t.Fatal("gathering failed:", err)
		}

		lg := NewGauge(GaugeOpts{Name: "testing", ConstLabels: Labels{"lbl": "1"}})
		lg.Set(42)
		pg := NewGauge(GaugeOpts{Name: "prefixtesting"})
		pg.Set(42)
		expected := toMetricFamilies(lg, pg)
		assertEqualMFs(t, expected, gathered)

		if !reg.Unregister(wrappedWithLabels) {
			t.Fatal("unregistering failed")
		}
		if !reg.Unregister(wrappedWithPrefix) {
			t.Fatal("unregistering failed")
		}

		gathered, err = reg.Gather()
		if err != nil {
			t.Fatal("gathering failed:", err)
		}
		if len(gathered) != 0 {
			t.Fatalf("expected 0 metric families, got %d", len(gathered))
		}
	})

	t.Run("can wrap same collector twice", func(t *testing.T) {
		inner := NewPedanticRegistry()
		g := NewGauge(GaugeOpts{Name: "testing"})
		g.Set(42)
		err := inner.Register(g)
		if err != nil {
			t.Fatal("registering failed:", err)
		}