Function TestNewMultiTRegistry

prometheus/registry_test.go:1199–1263

(t *testing.T)

}

func TestNewMultiTRegistry(t *testing.T) {
	treg := &tGatherer{}

	t.Run("one registry", func(t *testing.T) {
		m := prometheus.NewMultiTRegistry(treg)
		ret, done, err := m.Gather()
		if err != nil {
			t.Error("gather failed:", err)
		}
		done()
		if len(ret) != 1 {
			t.Error("unexpected number of metric families, expected 1, got", ret)
		}
		if !treg.done {
			t.Error("inner transactional registry not marked as done")
		}
	})

	reg := prometheus.NewRegistry()
	if err := reg.Register(prometheus.NewCounter(prometheus.CounterOpts{Name: "c1", Help: "help c1"})); err != nil {
		t.Error("registration failed:", err)
	}

	// Note on purpose two registries will have exactly same metric family name (but with different string).
	// This behaviour is undefined at the moment.
	if err := reg.Register(prometheus.NewGauge(prometheus.GaugeOpts{Name: "g1", Help: "help g1"})); err != nil {
		t.Error("registration failed:", err)
	}
	treg.done = false

	t.Run("two registries", func(t *testing.T) {
		m := prometheus.NewMultiTRegistry(prometheus.ToTransactionalGatherer(reg), treg)
		ret, done, err := m.Gather()
		if err != nil {
			t.Error("gather failed:", err)
		}
		done()
		if len(ret) != 3 {
			t.Error("unexpected number of metric families, expected 3, got", ret)
		}
		if !treg.done {
			t.Error("inner transactional registry not marked as done")
		}
	})

	treg.done = false
	// Inject error.
	treg.err = errors.New("test err")

	t.Run("two registries, one with error", func(t *testing.T) {
		m := prometheus.NewMultiTRegistry(prometheus.ToTransactionalGatherer(reg), treg)
		ret, done, err := m.Gather()
		if !errors.Is(err, treg.err) {
			t.Error("unexpected error:", err)
		}
		done()
		if len(ret) != 3 {
			t.Error("unexpected number of metric families, expected 3, got", ret)