func TestGauge(t *testing.T) {
var (
name = "xyz"
value = 54321
delta = 12345
g = expvar.NewGauge(name).With(metrics.Field{Key: "ignored", Value: "field"})
)
g.Set(float64(value))
g.Add(float64(delta))
if want, have := fmt.Sprint(value+delta), stdexpvar.Get(name).String(); want != have {
t.Errorf("want %q, have %q", want, have)
}
}
func TestMultiGauge(t *testing.T) {
g := metrics.NewMultiGauge(
"multidelta",
expvar.NewGauge("delta"),
prometheus.NewGauge(stdprometheus.GaugeOpts{
Namespace: "test",
Subsystem: "multi_gauge",
Name: "kappa",
Help: "Kappa gauge.",
}, []string{"a"}),
)
f := metrics.Field{Key: "a", Value: "aaa"}
g.With(f).Set(34)
if want, have := "34", stdexpvar.Get("delta").String(); want != have {
t.Errorf("expvar: want %q, have %q", want, have)
}
if want, have := strings.Join([]string{
`# HELP test_multi_gauge_kappa Kappa gauge.`,
`# TYPE test_multi_gauge_kappa gauge`,
`test_multi_gauge_kappa{a="aaa"} 34`,
}, "\n"), scrapePrometheus(t); !strings.Contains(have, want) {
t.Errorf("Prometheus metric stanza not found or incorrect\n%s", have)
}
g.With(f).Add(-40)
if want, have := "-6", stdexpvar.Get("delta").String(); want != have {
t.Errorf("expvar: want %q, have %q", want, have)
}
if want, have := strings.Join([]string{
`# HELP test_multi_gauge_kappa Kappa gauge.`,
`# TYPE test_multi_gauge_kappa gauge`,
`test_multi_gauge_kappa{a="aaa"} -6`,
}, "\n"), scrapePrometheus(t); !strings.Contains(have, want) {
t.Errorf("Prometheus metric stanza not found or incorrect\n%s", have)
}
}
// NewGauge implements Provider.
func (p expvarProvider) NewGauge(name string) metrics.Gauge {
return expvar.NewGauge(name)
}