Espresso Test 7: Idling resource

这是 Espresso UI 测试系列的第七篇文章。这篇主要是讲述 idling resources 的测试。

代码来源于 youtube 视频：https://www.youtube.com/watch?v=_96FT7E6PL4&list=PLgCYzUzKIBE_ZuZzgts135GuLQNX5eEPk&index=15&t=4s

1.0 知识点

Espresso idling resources
有时候我们进行异步操作任务，然后用返回的结果更新 UI， 这是常见的情况。这个时候，如果在进行 UI test,由于结果还没返回，这个是就会失败。

为了解决这个问题，就需要用到 idling resources 解决。

idling resources 常用的场景

• 从网络或本地加载数据
• 和数据库建立链接或回调
• 在使用到 Service 的时候
• 进行一些比较复杂的业务逻辑的时候

idling resources 常用的实现类

• CountingIdlingResource
  Maintains a counter of active tasks. When the counter is zero, the associated resource is considered idle. This functionality closely resembles that of a Semaphore. In most cases, this implementation is sufficient for managing your app’s asynchronous work during testing.

• UriIdlingResource
  Similar to CountingIdlingResource, but the counter needs to be zero for a specific period of time before the resource is considered idle. This additional waiting period takes consecutive network requests into account, where an app in your thread might make a new request immediately after receiving a response to a previous request.

• IdlingThreadPoolExecutor
  A custom implementation of ThreadPoolExecutor that keeps track of the total number of running tasks within the created thread pools. This class uses a CountingIdlingResource to maintain t