fix: otel not working without USER

pkg/observability/metrics/metrics_test.go

@@ -0,0 +1,121 @@
+package metrics
+
+import (
+	"bytes"
+	"net/http"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/go-kit/kit/metrics"
+	"github.com/go-kit/kit/metrics/generic"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestScalableHistogram(t *testing.T) {
+	h := generic.NewHistogram("test", 1)
+	sh, err := NewHistogramWithScale(h, time.Millisecond)
+	require.NoError(t, err)
+
+	ticker := time.NewTicker(500 * time.Millisecond)
+	<-ticker.C
+	start := time.Now()
+	<-ticker.C
+	sh.ObserveFromStart(start)
+
+	var b bytes.Buffer
+	h.Print(&b)
+
+	extractedDurationString := strings.Split(strings.Split(b.String(), "\n")[1], " ")
+	measuredDuration, err := time.ParseDuration(extractedDurationString[0] + "ms")
+	assert.NoError(t, err)
+
+	assert.InDelta(t, 500*time.Millisecond, measuredDuration, float64(15*time.Millisecond))
+}
+
+func TestNewMultiRegistry(t *testing.T) {
+	registries := []Registry{newCollectingRetryMetrics(), newCollectingRetryMetrics()}
+	registry := NewMultiRegistry(registries)
+
+	registry.ServiceReqsCounter().With(nil, "key", "requests").Add(1)
+	registry.ServiceReqDurationHistogram().With("key", "durations").Observe(float64(2))
+	registry.ServiceRetriesCounter().With("key", "retries").Add(3)
+
+	for _, collectingRegistry := range registries {
+		cReqsCounter := collectingRegistry.ServiceReqsCounter().(*counterWithHeadersMock)
+		cReqDurationHistogram := collectingRegistry.ServiceReqDurationHistogram().(*histogramMock)
+		cRetriesCounter := collectingRegistry.ServiceRetriesCounter().(*counterMock)
+
+		wantCounterValue := float64(1)
+		if cReqsCounter.counterValue != wantCounterValue {
+			t.Errorf("Got value %f for ReqsCounter, want %f", cReqsCounter.counterValue, wantCounterValue)
+		}
+		wantHistogramValue := float64(2)
+		if cReqDurationHistogram.lastHistogramValue != wantHistogramValue {
+			t.Errorf("Got last observation %f for ReqDurationHistogram, want %f", cReqDurationHistogram.lastHistogramValue, wantHistogramValue)
+		}
+		wantCounterValue = float64(3)
+		if cRetriesCounter.counterValue != wantCounterValue {
+			t.Errorf("Got value %f for RetriesCounter, want %f", cRetriesCounter.counterValue, wantCounterValue)
+		}
+
+		assert.Equal(t, []string{"key", "requests"}, cReqsCounter.lastLabelValues)
+		assert.Equal(t, []string{"key", "durations"}, cReqDurationHistogram.lastLabelValues)
+		assert.Equal(t, []string{"key", "retries"}, cRetriesCounter.lastLabelValues)
+	}
+}
+
+func newCollectingRetryMetrics() Registry {
+	return &standardRegistry{
+		serviceReqsCounter:          &counterWithHeadersMock{},
+		serviceReqDurationHistogram: &histogramMock{},
+		serviceRetriesCounter:       &counterMock{},
+	}
+}
+
+type counterMock struct {
+	counterValue    float64
+	lastLabelValues []string
+}
+
+func (c *counterMock) With(labelValues ...string) metrics.Counter {
+	c.lastLabelValues = labelValues
+	return c
+}
+
+func (c *counterMock) Add(delta float64) {
+	c.counterValue += delta
+}
+
+type counterWithHeadersMock struct {
+	counterValue    float64
+	lastLabelValues []string
+}
+
+func (c *counterWithHeadersMock) With(_ http.Header, labelValues ...string) CounterWithHeaders {
+	c.lastLabelValues = labelValues
+	return c
+}
+
+func (c *counterWithHeadersMock) Add(delta float64) {
+	c.counterValue += delta
+}
+
+type histogramMock struct {
+	lastHistogramValue float64
+	lastLabelValues    []string
+}
+
+func (c *histogramMock) With(labelValues ...string) ScalableHistogram {
+	c.lastLabelValues = labelValues
+	return c
+}
+
+func (c *histogramMock) Start() {}
+
+func (c *histogramMock) ObserveFromStart(t time.Time) {}
+
+func (c *histogramMock) Observe(v float64) {
+	c.lastHistogramValue = v
+}