LoginActivityUnitTest.kt

package com.cgbros.silkhub.activity.listener

import android.widget.TextView
import com.cgbros.silkhub.R
import com.cgbros.silkhub.activity.LoginActivity
import com.google.firebase.database.FirebaseDatabase
import org.junit.After
import org.junit.Assert.assertEquals
import org.junit.Before
import org.junit.Test
import org.robolectric.Robolectric
import org.mockito.Mockito.`when` as whenCalled

class LoginActivityUnitTest {

    @Before
    fun setup() {
        println("Setting up test environment...")
    }

    @After
    @Before
    fun cleanUp() {
        println("Cleaning up....")
        FirebaseDatabase.getInstance().reference.removeValue()
        println("Done!")
    }

    @Test
    fun shouldDisplayNumberOfOpenSessions() {

        // Given
        val activity = Robolectric.buildActivity(LoginActivity::class.java)
                .create()
                .start()
                .visible()
                .get()

        // When
        val openSessions = activity.findViewById<TextView>(R.id.login_open_sessions).text

        // Then
        assertEquals(openSessions, "1 open sessions")

    }

}