Android Espresso SwipeToRefreshLayout assert isRefreshing state

TestUtils.kt

import android.support.annotation.IdRes
import android.support.test.espresso.Espresso.onView
import android.support.test.espresso.assertion.ViewAssertions.matches
import android.support.test.espresso.matcher.ViewMatchers.withId
import android.support.v4.widget.SwipeRefreshLayout
import android.view.View
import org.hamcrest.Description
import org.hamcrest.Matchers.not
import org.hamcrest.TypeSafeMatcher
 
fun assertSwipeToRefreshState(@IdRes swipeToRefreshResId: Int,
                              stateShouldBeRefreshing: Boolean) {
    onView(withId(swipeToRefreshResId))
            .check(matches(
                    if (stateShouldBeRefreshing) {
                        isRefreshing()
                    } else {
                        not(isRefreshing())
                    }
            ))
}

private fun isRefreshing() = object : TypeSafeMatcher<View>() {

    override fun describeTo(description: Description) {
        description.appendText("is a SwipeRefreshLayout that is currently refreshing")
    }

    override fun matchesSafely(item: View?) =
            (item as? SwipeRefreshLayout)?.isRefreshing ?: false

}