tryCatchMiddleware function

Handler tryCatchMiddleware(Handler handler, { Future<Response> onError(dynamic, StackTrace)?, })

An Handler wrapper which calls the wrapped handler and does the following:

• when an instance of Response is returned or thrown by the wrapped handler, the response is returned
• when another error is thrown by the wrapped handler and the onError callback is set, the error will be converted to a response
• otherwise the error will be rethrown.

Implementation

Handler tryCatchMiddleware(Handler handler,
        {Future<Response> Function(dynamic, StackTrace)? onError}) =>
    (Request request) async {
      try {
        return await handler(request);
      } on Response catch (response) {
        return response;
      } catch (error, stacktrace) {
        return await onError?.call(error, stacktrace) ?? (throw error);
      }
    };