core_service.go

@@ -64,7 +64,7 @@ func NewCoreService(opts ServiceOptions) func(*core.Core) (any, error) {
 
 		if opts.Language != "" {
 			if langErr := svc.SetLanguage(opts.Language); langErr != nil {
-				return nil, core.Wrap(langErr, "NewCoreService", core.Sprintf("i18n: invalid language %q", opts.Language))
+				return nil, langErr
 			}
 		}
 

hooks_test.go

@@ -298,6 +298,18 @@ func TestNewCoreService_LoadsRegisteredLocales(t *testing.T) {
 	assert.Equal(t, "loaded on core bootstrap", got)
 }
 
+func TestNewCoreService_InvalidLanguagePreservesSetLanguageError(t *testing.T) {
+	factory := NewCoreService(ServiceOptions{Language: "es"})
+
+	_, err := factory(nil)
+	require.Error(t, err)
+
+	msg := err.Error()
+	assert.Contains(t, msg, "unsupported language: es")
+	assert.Contains(t, msg, "available:")
+	assert.NotContains(t, msg, "invalid language")
+}
+
 func TestInit_ReDetectsRegisteredLocales(t *testing.T) {
 	t.Setenv("LANG", "de_DE.UTF-8")