Address data race in pkg/locale

pkg/locale/service.go

@@ -421,6 +421,9 @@ func (svc *service) TResourceFor(tag language.Tag, ns, key string, rr ...string)
 func (svc *service) ResourceTranslations(tag language.Tag, resource string) ResourceTranslationIndex {
 	out := make(ResourceTranslationIndex)
 
+	svc.l.Lock()
+	defer svc.l.Unlock()
+
 	if svc != nil && svc.set != nil {
 		if l, has := svc.set[tag]; has {
 			return l.resourceTranslations(resource)

pkg/locale/service_test.go

@@ -0,0 +1,28 @@
+package locale
+
+import (
+	"testing"
+
+	"github.com/cortezaproject/corteza-server/pkg/options"
+	"github.com/stretchr/testify/require"
+	"go.uber.org/zap"
+	"golang.org/x/text/language"
+)
+
+// tested with
+// go test -count 10 -race -run TestServiceReloadAndTranslate ./pkg/locale/...
+func TestServiceReloadAndTranslate(t *testing.T) {
+	var (
+		req      = require.New(t)
+		svc, err = Service(zap.NewNop(), options.LocaleOpt{
+			Languages: "en",
+		})
+
+		tag = language.English
+	)
+
+	req.NoError(err)
+	req.NotNil(svc)
+	go svc.ResourceTranslations(tag, "resource")
+	go svc.ReloadStatic()
+}