How to write a first Espresso test

A first Espresso test should prove that the Android instrumentation runner can launch a real screen and that Espresso can find one view state after an interaction. Starting with one small assertion keeps the test focused on the project setup, runner, and screen wiring before a larger UI suite adds more branches.

ActivityScenarioRule starts the target activity for each test method and closes it after the method finishes. The test source belongs in the app module's androidTest source set, where AndroidX Test dependencies are available without shipping test code in the release APK.

A deterministic screen without a network request, login challenge, or seeded account makes the first run easier to interpret. View-based Android screens are the right target for Espresso; screens built only with Jetpack Compose should use the Compose testing APIs instead.

1. Add the minimal Espresso dependencies and instrumentation runner to the app module.

   build.gradle.kts

   android {
       defaultConfig {
           testInstrumentationRunner =
               "androidx.test.runner." +
                   "AndroidJUnitRunner"
       }
   }
    
   val espressoVersion = "3.7.0"
   val junitVersion = "1.3.0"
   val runnerVersion = "1.7.0"
    
   dependencies {
       androidTestImplementation(
           "androidx.test.espresso:" +
               "espresso-core:$espressoVersion"
       )
       androidTestImplementation(
           "androidx.test.ext:" +
               "junit:$junitVersion"
       )
       androidTestImplementation(
           "androidx.test:" +
               "runner:$runnerVersion"
       )
   }

   The versions shown match the current AndroidX Test releases in Google Maven. Keep the Espresso artifacts on the same release when adding more Espresso modules later.

2. Create the first test class under the app module's androidTest source set.

   WelcomeActivityTest.kt

   package com.example.app
    
   import androidx.test.espresso.Espresso.onView
   import androidx.test.espresso.action.ViewActions.*
   import androidx.test.espresso.assertion.ViewAssertions.*
   import androidx.test.espresso.matcher.ViewMatchers.*
   import androidx.test.ext.junit.rules.ActivityScenarioRule
   import androidx.test.ext.junit.runners.AndroidJUnit4
   import androidx.test.filters.LargeTest
   import org.junit.Rule
   import org.junit.Test
   import org.junit.runner.RunWith
    
   @RunWith(AndroidJUnit4::class)
   @LargeTest
   class WelcomeActivityTest {
    
       @get:Rule
       val activityRule =
           ActivityScenarioRule(WelcomeActivity::class.java)
    
       @Test
       fun tappingContinueShowsWelcomeMessage() {
           onView(withId(R.id.continue_button)).perform(click())
    
           onView(withId(R.id.message))
               .check(matches(withText("Welcome")))
       }
   }

3. Replace the sample activity, view IDs, and expected text with values from the screen under test.

   val activityRule =
       ActivityScenarioRule(MainActivity::class.java)
    
   onView(withId(R.id.sign_in)).perform(click())
    
   onView(withId(R.id.status))
       .check(
           matches(withText("Signed in"))
       )

   Use resource IDs for the first test when the app exposes them. Text-only matchers are easy to read but can break when copy changes or localization is enabled.

4. Run the connected Espresso test task on an emulator or device.

   $ ./gradlew connectedDebugAndroidTest
   
   Task :app:connectedDebugAndroidTest
   Starting 1 tests on Pixel_8_API_35
   Finished 1 tests on Pixel_8_API_35
   
   BUILD SUCCESSFUL in 31s

   The task name changes with the module and variant. Android projects with product flavors may expose a variant-specific task such as connectedFreeDebugAndroidTest.
   Related: How to run Espresso tests locally