ChangeTextBehaviorKtTest.kt

package com.example.android.testing.espresso.BasicSample

import androidx.test.ext.junit.rules.activityScenarioRule
import android.app.Activity
import androidx.test.core.app.ActivityScenario
import androidx.test.core.app.launchActivity
import androidx.test.espresso.Espresso.onView
import androidx.test.espresso.action.ViewActions
import androidx.test.espresso.action.ViewActions.*
import androidx.test.espresso.assertion.ViewAssertions.matches
import androidx.test.espresso.matcher.ViewMatchers
import androidx.test.espresso.matcher.ViewMatchers.withId
import androidx.test.espresso.matcher.ViewMatchers.withText
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.filters.LargeTest
import org.junit.Before
import org.junit.Rule
import org.junit.Test
import org.junit.runner.RunWith


/**
 * The kotlin equivalent to the ChangeTextBehaviorTest, that
 * showcases simple view matchers and actions like [ViewMatchers.withId],
 * [ViewActions.click] and [ViewActions.typeText], and ActivityScenarioRule
 *
 *
 * Note that there is no need to tell Espresso that a view is in a different [Activity].
 */
@RunWith(AndroidJUnit4::class)
@LargeTest
class ChangeTextBehaviorKtTest {

    /**
     * Use [ActivityScenarioRule] to create and launch the activity under test before each test,
     * and close it after each test. This is a replacement for
     * [androidx.test.rule.ActivityTestRule].
     */
    @get:Rule var activityScenarioRule = activityScenarioRule<MainActivity>()

    @Test
    fun changeText_sameActivity() {

        // Type text and then press the button.
        onView(withId(R.id.editTextUserInput))
                .perform(typeText(STRING_TO_BE_TYPED), closeSoftKeyboard())
        onView(withId(R.id.changeTextBt)).perform(click())

        // Check that the text was changed.
        onView(withId(R.id.textToBeChanged)).check(matches(withText(STRING_TO_BE_TYPED)))
    }

    @Test
    fun changeText_newActivity() {
        // Type text and then press the button.
        onView(withId(R.id.editTextUserInput)).perform(typeText(STRING_TO_BE_TYPED),
                closeSoftKeyboard())
        onView(withId(R.id.activityChangeTextBtn)).perform(click())

        // This view is in a different Activity, no need to tell Espresso.
        onView(withId(R.id.show_text_view)).check(matches(withText(STRING_TO_BE_TYPED)))
    }

    companion object {

        val STRING_TO_BE_TYPED = "Espresso"
    }
}