Unit test Android custom view with AndroidX Test and Robolectric

test_button_add.kt

@Test
fun testUiOfButtonAdd() {
    assertThat(buttonAdd.isEnabled).isTrue()
    assertThat(buttonAdd.visibility).isEqualTo(View.VISIBLE)
    assertThat(buttonAdd.text).isEqualTo(context.getString(R.string.button_add))
    assertThat(buttonAdd.textSize).isEqualTo(context.resources.getDimension(R.dimen.count_text_size))
}