如何为单元测试正确模拟数据对象？

如何解决如何为单元测试正确模拟数据对象？

我正在尝试对一段类似于下面的代码段的代码进行单元测试。

class Myviewmodel : Androidviewmodel() {

    /**
     * Indicates whether or not an empty state message should be displayed.
     */
    val noMatchingDataLiveData: LiveData<Boolean> by lazy {
        noMatchingDataSubject
            // Ignore the first value
            .skip(1)

            // Only emit after every 2 items,since each data change from the adapter emits 2 messages
            .buffer(2)

            // Only emit the most recent of the 2 items
            .map { it.last() }

            .toFlowable(BackpressureStrategy.LATEST)

            // Transforms an RX observable to a LiveData via LiveDataReactiveStreamsKt
            .toLiveData()
    }

    /**
     * The backing subject for [noMatchingDataLiveData].
     */
    private val noMatchingDataSubject = BehaviorSubject.createDefault<Boolean>(false)

    /**
     * The recycler view adapter.
     */
    internal val myRecyclerAdapter: FirestoreRecyclerAdapter<MyWidget,MyWidgetViewHolder> by lazy {
        object : FirestoreRecyclerAdapter<MyWidget,MyWidgetViewHolder>(...) {

            override fun onCreateViewHolder(group: ViewGroup,i: Int): MyWidgetViewHolder {
                return MyWidgetViewHolder(LayoutInflater.from(group.context).inflate(R.layout.my_widget_item,group,false))
            }

            override fun onBindViewHolder(
                holder: MyWidgetViewHolder,position: Int,model: MyWidget) {
                ...
            }

            override fun onDataChanged() {
                // Note that each time the query is changed,this is invoked twice:
                // The first invocation always has 0 items,because the offline cache was just cleared
                // The second invocation will have the number of items matching the query,when the offline cache is updated

                // Our subject uses a buffer to only emit every-other item
                noMatchingDataSubject.onNext(this.itemCount < 1)
            }

            override fun onError(e: FirebaseFirestoreException) {
                ...
            }
        }
    }
}

在添加 .filter 用法后，我在现有测试中看到诸如“无法读取未定义的属性‘过滤器’”之类的错误。我怎样才能在我的单元测试中正确地模拟这个，以便过滤器被识别为一个函数？目前，测试正在传入一个如下所示的数据对象：

const getSubscriptions = {
     options: {
         async handler({query}) {
             const workType = searchParams.get('workType');

             return axios.get(url,{
                 headers: {
                     Authorization: `Bearer ${clientCredentials.access_token}`
                 }
             }).then((response) => {
                 if (workType && workType.length > 0) {
                     if (workType === 'UnkNown') {
                         response.data._embedded = response.data._embedded.filter((subscriptions) => !subscriptions.systemProperties.workType);
                     } else {
                         response.data._embedded = response.data._embedded.filter((subscriptions) => subscriptions.systemProperties.workType && subscriptions.systemProperties.workType === workType);
                     }
                 }

                 return response.data;
             })
         }
     },method: 'GET',path: '/subscriptions'};

我尝试编辑此数据对象以包含 _embedded，然后我收到一个错误，指出 .filter 不是函数。

我是为 JavaScript 编写单元测试的新手，所以我已经坚持了一段时间。任何帮助表示赞赏。我正在使用 Mocha 进行测试，但也可能会解释 Jasmine 或 Jest 解决方案。

这是测试套件的精简版：

data: [chance.object(),chance.object()]

解决方法

代码试图过滤 response.data._embedded 数组 — response.data 是一个对象。您应该将响应数据模拟为对象（具有 _embedded 属性）而不是数组。

{
  data: [chance.object(),chance.object()]
}

应该

{
  data: {
    _embedded: [
      // ...
    ]
  }
}