ReactiveUI:从单元测试中测试可观察的属性 [英] ReactiveUI: Testing observable properties from unit tests

问题描述

有这个 示例 官方 RX 博客:

There is this example on the official RX blog:

var scheduler = new TestScheduler();

var xs = scheduler.CreateColdObservable(
    OnNext(10, 42),
    OnCompleted<int>(20)
);

var res = scheduler.Start(() => xs);

res.Messages.AssertEqual(
    OnNext(210, 42),            // Subscribed + 10
    OnCompleted<int>(220)       // Subscribed + 20
);

xs.Subscriptions.AssertEqual(
    Subscribe(200, 1000)        // [Subscribed, Disposed]
);

我想用reactiveui做这样的事情.我的意思是而不是 scheduler.CreateColdObservable(...) 使用来自实际属性更改通知的流.问题是我尝试了 vm.ObservableForProperty 和 vm.Changed 但它们的工作不一致(并非所有属性更改都创建了一个事件或值为空)

I'd like to do something like this with reactiveui. I mean instead of the scheduler.CreateColdObservable(...) use the streams from actual property change notification. The problem is that I tried vm.ObservableForProperty and vm.Changed but they worked inconsistently (not all property change created an event or the value was null)

这是我的虚拟机的代码:

Here is the code of my VM:

internal class ProductFileEditorVM : ReactiveObject
{
    private readonly List<string> _preloadedList;

    private bool _OnlyContainingProduct;
    public bool OnlyContainingProduct
    {
        get { return _OnlyContainingProduct; }
        set
        {
            this.RaiseAndSetIfChanged(x => x.OnlyContainingProduct, value);
        }
    }

    private ObservableAsPropertyHelper<IEnumerable<string>> _RepoList;
    public IEnumerable<string> RepoList
    {
        get{return _RepoList.Value;}
    }

    public ProductFileEditorVM(RepositoryManager repositoryManager)
    {

        //Set defaults
        OnlyContainingProduct = true;

        //Preload
        _preloadedList = repositoryManager.GetList();

        var list = this.WhenAny(x => x.OnlyContainingProduct,
                     ocp =>
                     ocp.Value
                         ? _preloadedRepoList.Where(repo => repo.ToLower().Contains("product"))
                         : _preloadedRepoList);
        list.ToProperty(this, x => x.RepoList);
    }
}

理想情况下，我想在两个属性上使用 Observable.CombineLatest 并创建一个元组，然后像第一个示例一样在断言表达式中比较这个元组.

Ideally I'd like to use Observable.CombineLatest on the two property and creating a tuple and comparing this tuple in the assert expression like in the first example.

好的结果是:

1. [OnlyContainingProduct==true;RepoList=过滤后的]
2. !将 OnlyContainingProduct 更改为 false
3. [OnlyContainingProduct==false;RepoList=整个列表]

*或者这是错误的处理方式?我看到的关于此的唯一示例使用了诸如毫秒之类的实际时间度量，但除了 Throttle 和类似方法之外，我看不出它们有什么用处.*

推荐答案

所以，因为你不做与时间相关的测试，只做基于顺序的测试(即我做了这个，然后我做了这个，那么它应该是那个)，写一个普通的单元测试实际上要简单得多.TestScheduler 是个大锤子:)

So, because you're not doing tests that are related to time, only tests that are based on order (i.e. "I did This, then I did This, then it should be That), it's actually far simpler to just write a normal unit test. TestScheduler is a big hammer :)

因此，您可以执行以下操作:

So, you could do something like:

var fixture = new ProductFileEditorVM();

bool repoListChanged = false;
fixture.WhenAny(x => x.RepoList, x => x.Value)
    .Subscribe(_ => repoListChanged = true);

fixture.OnlyContainingProduct = true;
Assert.True(repoListChanged);

何时使用 TestScheduler

但是，如果加载 RepoList 是异步的并且可能需要一些时间，并且您想要表示正在加载"状态，那么 TestScheduler 会对此有好处 - 您可以在 +20ms、AdvanceTo(200ms) 处单击复选框, 检查您是否处于 Loading 状态，AdvanceTo(10min)，然后查看列表是否已更新且状态不是 Loading

When to use TestScheduler

However, if loading RepoList was asynchronous and could take some time, and you wanted to represent a "Loading" state, a TestScheduler would be good for that - you'd click the checkbox at say +20ms, AdvanceTo(200ms), check to see if you're in Loading state, AdvanceTo(10min), then see that the list is updated and the state isn't Loading

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