Alerting: Fix database unavailable removes rules from scheduler (#49874)

pkg/services/ngalert/schedule/fetcher_test.go

@@ -0,0 +1,26 @@
+package schedule
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/grafana/grafana/pkg/services/ngalert/models"
+)
+
+func TestHashUIDs(t *testing.T) {
+	r := []*models.SchedulableAlertRule{{UID: "foo"}, {UID: "bar"}}
+	assert.Equal(t, uint64(0xade76f55c76a1c48), hashUIDs(r))
+	// expect the same hash irrespective of order
+	r = []*models.SchedulableAlertRule{{UID: "bar"}, {UID: "foo"}}
+	assert.Equal(t, uint64(0xade76f55c76a1c48), hashUIDs(r))
+	// expect a different hash
+	r = []*models.SchedulableAlertRule{{UID: "bar"}}
+	assert.Equal(t, uint64(0xd8d9a5186bad3880), hashUIDs(r))
+	// slice with no items
+	r = []*models.SchedulableAlertRule{}
+	assert.Equal(t, uint64(0xcbf29ce484222325), hashUIDs(r))
+	// a different slice with no items should have the same hash
+	r = []*models.SchedulableAlertRule{}
+	assert.Equal(t, uint64(0xcbf29ce484222325), hashUIDs(r))
+}