add unit test for prometheus extension

Author: gangachris

extension/prometheus/prometheus_test.go

@@ -0,0 +1,34 @@
+// +build unit
+
+package prometheus
+
+import (
+	"fmt"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/hellofresh/goengine/driver/sql"
+)
+
+func TestPrometheusMetrics(t *testing.T) {
+	metrics := NewMetrics()
+
+	testSQLProjection := sql.ProjectionNotification{
+		No:          1,
+		AggregateID: "C56A4180-65AA-42EC-A945-5FD21DEC0538",
+	}
+
+	metrics.QueueNotification(&testSQLProjection)
+	metrics.StartNotificationProcessing(&testSQLProjection)
+
+	memAddress := fmt.Sprintf("%p", &testSQLProjection)
+	queueStartTime, ok := metrics.notificationStartTimes.Load("q" + memAddress)
+	assert.True(t, ok)
+	assert.IsType(t, time.Time{}, queueStartTime)
+
+	processingStartTime, _ := metrics.notificationStartTimes.Load("p" + memAddress)
+	assert.True(t, ok)
+	assert.IsType(t, time.Time{}, processingStartTime)
+}