First I added the following UI Automator to my app:
androidTestImplementation 'com.android.support.test.uiautomator:uiautomator-v18:2.1.3'So now my build.gradle (Module) file has the following dependecies:
dependencies {
implementation 'androidx.core:core-ktx:1.7.0'
implementation 'androidx.appcompat:appcompat:1.5.1'
implementation 'com.google.android.material:material:1.6.1'
implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
implementation 'net.objecthunter:exp4j:0.4.8'
testImplementation 'junit:junit:4.13.2'
androidTestImplementation 'androidx.test.ext:junit:1.1.3'
androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
androidTestImplementation 'com.android.support.test.uiautomator:uiautomator-v18:2.1.3'
}Then under the package app/src/androidTest/java/net/catzie/samplecalculatorapp I added the following instrumented test class:
package net.catzie.samplecalculatorapp
import android.support.test.uiautomator.UiDevice
import androidx.test.espresso.Espresso
import androidx.test.espresso.ViewInteraction
import androidx.test.espresso.action.ViewActions
import androidx.test.espresso.matcher.ViewMatchers
import androidx.test.ext.junit.rules.ActivityScenarioRule
import androidx.test.ext.junit.runners.AndroidJUnit4
import androidx.test.platform.app.InstrumentationRegistry.getInstrumentation
import org.junit.Assert.*
import org.junit.Rule
import org.junit.Test
import org.junit.runner.RunWith
/**
* Instrumented test, which will execute on an Android device.
*
* See [testing documentation](http://d.android.com/tools/testing).
*/
@RunWith(AndroidJUnit4::class)
class ValueRetainedInstrumentedTest {
@get:Rule
var activityRule: ActivityScenarioRule<MainActivity>
= ActivityScenarioRule(MainActivity::class.java)
@Test
fun test_ui_value_after_screen_rotation() {
Espresso.onView(ViewMatchers.withId(R.id.num_1)).perform(ViewActions.click())
Espresso.onView(ViewMatchers.withId(R.id.num_period)).perform(ViewActions.click())
Espresso.onView(ViewMatchers.withId(R.id.num_5)).perform(ViewActions.click())
val device = UiDevice.getInstance(getInstrumentation())
device.setOrientationLeft()
val displayPanel: ViewInteraction = Espresso.onView(ViewMatchers.withId(R.id.display_panel))
val displayPanelText = InstrumentedTestHelper.getText(displayPanel)
assertEquals("1.5", displayPanelText)
}
}What it does is press the buttons 1, period, and 5 on the calculator’s UI to show “1.5” which should show up the display panel, rotate the screen of the emulator/device, and then check if the display panel is still showing the value “1.5”.
I use a ViewModel and LiveData to let the value survive configuration changes such as screen rotation.
