fix: unused param, mock defaults, reconnect nil guard

Author: retran

mdl/backend/mock/mock_mutation.go

@@ -101,12 +101,12 @@ func (m *MockBackend) BuildDataGrid2Widget(id model.ID, name string, spec backen
 	if m.BuildDataGrid2WidgetFunc != nil {
 		return m.BuildDataGrid2WidgetFunc(id, name, spec, projectPath)
 	}
-	return nil, nil
+	return nil, fmt.Errorf("MockBackend.BuildDataGrid2Widget not configured")
 }
 
 func (m *MockBackend) BuildFilterWidget(spec backend.FilterWidgetSpec, projectPath string) (pages.Widget, error) {
 	if m.BuildFilterWidgetFunc != nil {
 		return m.BuildFilterWidgetFunc(spec, projectPath)
 	}
-	return nil, nil
+	return nil, fmt.Errorf("MockBackend.BuildFilterWidget not configured")
 }

mdl/backend/mpr/datagrid_builder.go

@@ -699,7 +699,7 @@ func (b *MprBackend) applyDataGridSelectionProp(obj bson.D, propertyTypeIDs map[
 // BSON property builders (package-level, no receiver needed)
 // ===========================================================================
 
-func buildDataGrid2Property(entry pages.PropertyTypeIDEntry, datasource pages.DataSource, attrRef string, primitiveValue string, b *MprBackend) bson.D {
+func buildDataGrid2Property(entry pages.PropertyTypeIDEntry, datasource pages.DataSource, attrRef string, primitiveValue string, _ *MprBackend) bson.D {
 	var datasourceBSON any
 	if datasource != nil {
 		datasourceBSON = mpr.SerializeCustomWidgetDataSource(datasource)

mdl/executor/executor_connect.go

@@ -65,6 +65,9 @@ func reconnect(ctx *ExecContext) error {
 	}
 
 	// Reopen connection
+	if e.backendFactory == nil {
+		return mdlerrors.NewBackend("reconnect", fmt.Errorf("no backend factory configured"))
+	}
 	b := e.backendFactory()
 	if err := b.Connect(e.mprPath); err != nil {
 		return mdlerrors.NewBackend("reconnect", err)