Move metrics to metrics/ pacakge

metrics/metrics_test.go

@@ -0,0 +1,58 @@
+package metrics
+
+import (
+	"sort"
+	"strings"
+	"testing"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/stretchr/testify/require"
+)
+
+// expectedMetricNames is the exact set of metrics the server exposes. These names are a public
+// contract: renaming or dropping one silently breaks existing dashboards and alerts.
+var expectedMetricNames = []string{
+	"ntfy_attachments_total_size",
+	"ntfy_calls_made_failure",
+	"ntfy_calls_made_success",
+	"ntfy_emails_received_failure",
+	"ntfy_emails_received_success",
+	"ntfy_emails_sent_failure",
+	"ntfy_emails_sent_success",
+	"ntfy_firebase_published_failure",
+	"ntfy_firebase_published_success",
+	"ntfy_http_requests_total",
+	"ntfy_matrix_published_failure",
+	"ntfy_matrix_published_success",
+	"ntfy_message_publish_duration_ms",
+	"ntfy_messages_cached_total",
+	"ntfy_messages_published_failure",
+	"ntfy_messages_published_success",
+	"ntfy_subscribers_total",
+	"ntfy_topics_total",
+	"ntfy_unifiedpush_published_success",
+	"ntfy_users_total",
+	"ntfy_visitors_total",
+}
+
+func TestRegisteredMetricNames(t *testing.T) {
+	HTTPRequests.WithLabelValues("200", "20000", "GET").Inc()
+	families, err := prometheus.DefaultGatherer.Gather()
+	require.Nil(t, err)
+	names := make([]string, 0)
+	for _, family := range families {
+		if strings.HasPrefix(family.GetName(), "ntfy_") {
+			names = append(names, family.GetName())
+		}
+	}
+	sort.Strings(names)
+	require.Equal(t, expectedMetricNames, names)
+}
+
+func TestCollectors_NeverNil(t *testing.T) {
+	// Call sites update metrics unconditionally, even when metrics are disabled, so no collector
+	// may ever be nil
+	MessagesPublishedSuccess.Inc()
+	MessagesCached.Set(1)
+	HTTPRequests.WithLabelValues("200", "20000", "PUT").Inc()
+}