public static JsToken AssertExpression(this ScriptScopeContext scope, string filterName, object expression, object scopeOptions, out string itemBinding) { if (expression is JsArrowFunctionExpression arrowExpr) { itemBinding = arrowExpr.Params[0].Name; return(arrowExpr.Body); } var literal = scope.AssertExpression(filterName, expression); var scopedParams = scope.GetParamsWithItemBinding(filterName, scopeOptions, out itemBinding); var token = literal.GetCachedJsExpression(scope); return(token); }