java - How can I test the result of a button click that changes the Activity's view asynchronously?

Question

I am trying to write some Activity tests for an app, and one particular scenario that I want to test is that when I click a certain button, the Activity view updates accordingly. However, clicking the button causes a somewhat long running asynchronous task to start and only after that task is completed does the view change.

How can I test this? I'm currently trying to use the ActivityInstrumentationTestCase2 class to accomplish this, but am having trouble figuring out how to have the test 'wait' until the asynchronous part of the button click task is complete and the view updates.

Answer 1

The most common and simplest solution is to use Thread.sleep():

public void testFoo() {
  TextView textView = (TextView) myActivity.findViewById(com.company.app.R.id.text);
  assertEquals("text should be empty", "", textView.getText());

  // simulate a button click, which start an AsyncTask and update TextView when done.
  final Button button = (Button) myActivity.findViewById(com.company.app.R.id.refresh);
  myActivity.runOnUiThread(new Runnable() {
    public void run() {
      button.performClick();
    }
  });

  // assume AsyncTask will be finished in 6 seconds.
  try {
    Thread.sleep(6000);
  } catch (InterruptedException e) {
    e.printStackTrace();
  }

  assertEquals("text should be refreshed", "refreshed", textView.getText());
}

Hope this helps.