BenoitDuffez

O let<I extends Object, O>(
    I? value, 
    O Function(I) cb, 
   {O Function()? or}) {
  if (value != null) {
    return cb(value);
  }
  if (or != null) {
    return or();
  }

BenoitDuffez

import 'package:flutter_test/flutter_test.dart';

extension Let<T extends Object> on T? {
  R let<R>(R Function(T) callback, {R Function()? or}) {
    var self = this;
    if (self != null) {
      return callback(self);
    }
    if (or != null) {
      return or();