Add Metrics

pkg/middlewares/metrics/metrics_test.go

@@ -0,0 +1,58 @@
+package metrics
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"reflect"
+	"testing"
+
+	"github.com/go-kit/kit/metrics"
+)
+
+// CollectingCounter is a metrics.Counter implementation that enables access to the CounterValue and LastLabelValues.
+type CollectingCounter struct {
+	CounterValue    float64
+	LastLabelValues []string
+}
+
+// With is there to satisfy the metrics.Counter interface.
+func (c *CollectingCounter) With(labelValues ...string) metrics.Counter {
+	c.LastLabelValues = labelValues
+	return c
+}
+
+// Add is there to satisfy the metrics.Counter interface.
+func (c *CollectingCounter) Add(delta float64) {
+	c.CounterValue += delta
+}
+
+func TestMetricsRetryListener(t *testing.T) {
+	req := httptest.NewRequest(http.MethodGet, "/", nil)
+	retryMetrics := newCollectingRetryMetrics()
+	retryListener := NewRetryListener(retryMetrics, "serviceName")
+	retryListener.Retried(req, 1)
+	retryListener.Retried(req, 2)
+
+	wantCounterValue := float64(2)
+	if retryMetrics.retriesCounter.CounterValue != wantCounterValue {
+		t.Errorf("got counter value of %f, want %f", retryMetrics.retriesCounter.CounterValue, wantCounterValue)
+	}
+
+	wantLabelValues := []string{"service", "serviceName"}
+	if !reflect.DeepEqual(retryMetrics.retriesCounter.LastLabelValues, wantLabelValues) {
+		t.Errorf("wrong label values %v used, want %v", retryMetrics.retriesCounter.LastLabelValues, wantLabelValues)
+	}
+}
+
+// collectingRetryMetrics is an implementation of the retryMetrics interface that can be used inside tests to collect the times Add() was called.
+type collectingRetryMetrics struct {
+	retriesCounter *CollectingCounter
+}
+
+func newCollectingRetryMetrics() *collectingRetryMetrics {
+	return &collectingRetryMetrics{retriesCounter: &CollectingCounter{}}
+}
+
+func (m *collectingRetryMetrics) ServiceRetriesCounter() metrics.Counter {
+	return m.retriesCounter
+}