Espresso Custom View Matcher to check Vector Drawable Icon

CustomMatchers.kt

import android.content.Context
import android.graphics.Bitmap
import android.graphics.Canvas
import android.graphics.drawable.BitmapDrawable
import android.graphics.drawable.Drawable
import android.graphics.drawable.StateListDrawable
import android.graphics.drawable.VectorDrawable
import android.support.annotation.DrawableRes
import android.support.test.espresso.matcher.BoundedMatcher
import android.support.v4.content.ContextCompat
import android.support.v7.view.menu.ActionMenuItemView
import android.view.View
import org.hamcrest.Description
import org.hamcrest.Matcher

/**
 * Apache 2.0
 *
 * @see <a href="https://github.com/stablekernel/EspressoLib/blob/master/src/main/java/com/stablekernel/espressolib/DrawableMatcher.java">Source1</a>
 * @see <a href="http://stackoverflow.com/questions/33696488/getting-bitmap-from-vector-drawable">Source2</a>
 */
object CustomMatchers {

    fun withIcon(@DrawableRes resourceId: Int): Matcher<View> {
        return object : BoundedMatcher<View, ActionMenuItemView>(ActionMenuItemView::class.java) {
            override fun describeTo(description: Description) {
                description.appendText("has image drawable resource $resourceId")
            }

            public override fun matchesSafely(actionMenuItemView: ActionMenuItemView): Boolean {
                return sameBitmap(actionMenuItemView.context, actionMenuItemView.itemData.icon, resourceId)
            }
        }
    }

    private fun sameBitmap(context: Context, drawable: Drawable?, resourceId: Int): Boolean {
        var drawable = drawable
        var otherDrawable: Drawable? = ContextCompat.getDrawable(context, resourceId)
        if (drawable == null || otherDrawable == null) {
            return false
        }
        if (drawable is StateListDrawable && otherDrawable is StateListDrawable) {
            drawable = drawable.current
            otherDrawable = otherDrawable.current
        }

        val bitmap = if (drawable is VectorDrawable) vectorToBitmap(drawable)
        else (drawable as BitmapDrawable).bitmap
        val otherBitmap = if (otherDrawable is VectorDrawable) vectorToBitmap(otherDrawable)
        else (otherDrawable as BitmapDrawable).bitmap
        return bitmap.sameAs(otherBitmap)
    }

    private fun vectorToBitmap(vectorDrawable: VectorDrawable): Bitmap {
        val bitmap = Bitmap.createBitmap(vectorDrawable.intrinsicWidth, vectorDrawable.intrinsicHeight, Bitmap.Config.ARGB_8888)
        val canvas = Canvas(bitmap)
        vectorDrawable.setBounds(0, 0, canvas.width, canvas.height)
        vectorDrawable.draw(canvas)
        return bitmap
    }
}