Unresolved reference: ext when importing androidx.test.ext.junit.rules.ActivityScenarioRule

Issue

Recently, I've decided to update my Espresso code to use ActivityScenarioRule instead of the deprecated ActivityTestRule.

To do this, I've imported the following library into my project:

The final code using ActivityScenarioRule:

package com.realtomjoney.pyxlmoose.activities.main

import androidx.test.espresso.Espresso.onView
import androidx.test.espresso.action.ViewActions
import androidx.test.espresso.matcher.ViewMatchers.*
import com.realtomjoney.pyxlmoose.R
import org.junit.Rule
import org.junit.Test
import androidx.test.espresso.action.ViewActions.click
import androidx.test.espresso.assertion.ViewAssertions
import androidx.test.ext.junit.rules.ActivityScenarioRule
import androidx.test.filters.LargeTest
import androidx.test.internal.runner.junit4.AndroidJUnit4ClassRunner
import org.junit.runner.RunWith


@LargeTest
@RunWith(AndroidJUnit4ClassRunner::class)
class MainActivityTestsWhenNewProjectIsCreated {
    @get:Rule
    var activityTestRule = ActivityScenarioRule(MainActivity::class.java)

    private fun createNewProject() {
        onView(withId(R.id.floatingActionButton)).perform(click())
        onView(withId(R.id.fragmentNewCanvas_projectTitleTextInputEditText)).perform(ViewActions.replaceText("Untitled Project"))
        onView(withId(R.id.fragmentNewCanvas_spanCountTextInputEditText)).perform(ViewActions.replaceText("5"))
        onView(withId(R.id.fragmentNewCanvas_doneButton)).perform(click())
    }

    @Test
    fun uitest_fragmentNewCanvasProjectTitleTextInputEditText_isNotDisplayed_after_fragmentNewCanvasDoneButton_isPressed() {
        createNewProject()
        onView(withId(R.id.fragmentNewCanvas_projectTitleTextInputEditText)).check(ViewAssertions.doesNotExist())
    }

    @Test
    fun uitest_fragmentNewCanvasProjectTitleTextInputLayout_isNotDisplayed_after_fragmentNewCanvasDoneButton_isPressed() {
        createNewProject()
        onView(withId(R.id.fragmentNewCanvas_projectTitleTextInputLayout)).check(ViewAssertions.doesNotExist())
    }

    @Test
    fun uitest_fragmentNewCanvasSpanCountTextInputEditText_isNotDisplayed_after_fragmentNewCanvasDoneButton_isPressed() {
        createNewProject()
        onView(withId(R.id.fragmentNewCanvas_spanCountTextInputEditText)).check(ViewAssertions.doesNotExist())
    }

    @Test
    fun uitest_fragmentNewCanvasSpanCountTextInputLayout_isNotDisplayed_after_fragmentNewCanvasDoneButton_isPressed() {
        createNewProject()
        onView(withId(R.id.fragmentNewCanvas_spanCountTextInputLayout)).check(ViewAssertions.doesNotExist())
    }

    @Test
    fun uitest_fragmentNewCanvasDoneButton_isNotDisplayed_after_fragmentNewCanvasDoneButton_isPressed() {
        createNewProject()
        onView(withId(R.id.fragmentNewCanvas_doneButton)).check(ViewAssertions.doesNotExist())
    }
}

Whenever I run the UI tests, I get the following error:

Unresolved reference: ext

The error is coming from this line:

import androidx.test.ext.junit.rules.ActivityScenarioRule

build.gradle:

plugins {
    id 'com.android.application'
    id 'kotlin-android'
}

android {
    compileSdk 31

    testOptions {
        unitTests.includeAndroidResources = true
    }

    defaultConfig {
        applicationId "com.realtomjoney.pyxlmoose"
        minSdk 27
        targetSdk 31
        versionCode 1
        versionName "1.0"

        testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
        }
    }
    compileOptions {
        sourceCompatibility JavaVersion.VERSION_1_8
        targetCompatibility JavaVersion.VERSION_1_8
    }
    kotlinOptions {
        jvmTarget = '1.8'
    }
    buildFeatures {
        viewBinding true
    }
    testOptions {
        unitTests.returnDefaultValues = true
    }
}

dependencies {
    implementation 'androidx.core:core-ktx:1.7.0'
    implementation 'androidx.appcompat:appcompat:1.4.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.2'
//    implementation 'androidx.test:core-ktx:1.4.0'
    implementation 'com.google.android.material:material:1.5.0-beta01'
    testImplementation 'junit:junit:4.13.2'
    testImplementation 'androidx.test:core-ktx:1.4.0'
    testImplementation 'androidx.test.ext:junit-ktx:1.1.3'
    testImplementation 'org.robolectric:robolectric:4.4'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.0-alpha03'
    androidTestImplementation 'androidx.test:rules:1.4.1-alpha03'
    androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
    androidTestImplementation 'com.android.support.test.espresso:espresso-contrib:3.0.2'
}

Does anybody have any idea how to fix this? This import statement was added automatically by Android Studio, and I'm confused why it's saying that 'ext' is an unresolved reference. Any help would be greatly appreciated.

It's not that the code with ActivityTestRule doesn't work, I just wanted to switch to a safer alternative which seems to be ActivityScenarioRule - if I keep running into these problems I might need to revert back to the deprecated library.

If I can improve this question in any way, please let me know in the comments.

Solution

Uhh, wait a second, I already have implementation 'androidx.test:core-ktx:1.4.0' included in my project... The commented out one is just a duplicate lol

You have it imported as testImplementation - it should be androidTestImplementation.

How you declare the dependency depends on what kind of tests are going to use it. testImplementation is for anything under test/ (usually unit tests that don't depend on the Android framework). Anything that does depend on the Android framework goes under androidTest/ and so would use androidTestImplementation:

androidTestImplementation 'androidx.test.ext:junit-ktx:1.1.3'

Answered By - dominicoder