android - Espresso: Thread.sleep( )

Question

Espresso claims that there is no need for Thread.sleep() but my code doesn't work unless I include it. I am connecting to an IP and, while connecting, a progress dialog is shown. I need a Thread.sleep() call to wait for the dialog to dismiss. This is my test code where I use it:

    IP.enterIP(); // fills out an IP dialog (this is done with espresso)

    //progress dialog is now shown
    Thread.sleep(1500);

    onView(withId(R.id.button).perform(click());

I have tried this code without the Thread.sleep() call but it says R.id.Button doesn't exist. The only way I can get it to work is with the Thread.sleep() call.

Also, I have tried replacing Thread.sleep() with things like getInstrumentation().waitForIdleSync() and still no luck.

Is this the only way to do this? Or am I missing something?

Thanks in advance.

Answer 1

On my mind correct approach will be:

/** Perform action of waiting for a specific view id. */
public static ViewAction waitId(final int viewId, final long millis) {
    return new ViewAction() {
        @Override
        public Matcher<View> getConstraints() {
            return isRoot();
        }

        @Override
        public String getDescription() {
            return "wait for a specific view with id <" + viewId + "> during " + millis + " millis.";
        }

        @Override
        public void perform(final UiController uiController, final View view) {
            uiController.loopMainThreadUntilIdle();
            final long startTime = System.currentTimeMillis();
            final long endTime = startTime + millis;
            final Matcher<View> viewMatcher = withId(viewId);

            do {
                for (View child : TreeIterables.breadthFirstViewTraversal(view)) {
                    // found view with required ID
                    if (viewMatcher.matches(child)) {
                        return;
                    }
                }

                uiController.loopMainThreadForAtLeast(50);
            }
            while (System.currentTimeMillis() < endTime);

            // timeout happens
            throw new PerformException.Builder()
                    .withActionDescription(this.getDescription())
                    .withViewDescription(HumanReadables.describe(view))
                    .withCause(new TimeoutException())
                    .build();
        }
    };
}

And then pattern of usage will be:

// wait during 15 seconds for a view
onView(isRoot()).perform(waitId(R.id.dialogEditor, TimeUnit.SECONDS.toMillis(15)));