Android Testing Example - Simple Unit test creation

SimpleUnitTest.kt

package com.coderefer.androidtestingexamples

import kotlinx.android.synthetic.main.activity_main.*
import org.junit.Test
import org.junit.Assert.*
import org.junit.runner.RunWith
import org.robolectric.Robolectric
import org.robolectric.RobolectricTestRunner


/**
 * Simple local unit test, which will execute on the development machine (host).
 *
 * See [testing documentation](http://d.android.com/tools/testing).
 */
@RunWith(RobolectricTestRunner::class)
class SimpleUnitTest {
    @Test
    fun buttonText(){
        var activity = Robolectric.setupActivity(MainActivity::class.java)
        activity.button.performClick()
        assertEquals(activity.textView.text,"hello")
    }
}