How to set a specific rating on RatingBar in Espresso?

Question

I'm trying to write an Espresso test that tests a RatingBar selection. How can I set a specific rating using Espresso? I only see click(), which always sets the middle rating.

Answer 1

You need to create a custom subclass of ViewAction that calls setRating on the view, then pass an instance of your custom view action to the perform() method.

Answer 2

The accepted answer helped me write the following custom ViewAction:

public final class SetRating implements ViewAction {

    @Override
    public Matcher<View> getConstraints() {
        Matcher <View> isRatingBarConstraint = ViewMatchers.isAssignableFrom(RatingBar.class);
        return isRatingBarConstraint;
    }

    @Override
    public String getDescription() {
        return "Custom view action to set rating.";
    }

    @Override
    public void perform(UiController uiController, View view) {
        RatingBar ratingBar = (RatingBar) view;
        ratingBar.setRating(3);
    }
}