How to test WebView content with Espresso-Web

Hybrid Android screens can render important state inside a WebView where normal Espresso view matchers stop at the native widget. Espresso-Web crosses that boundary by running WebDriver-style atoms inside the document, so a test can find DOM elements, type into fields, click controls, and assert rendered page text.

The espresso-web artifact belongs in the app module's androidTest classpath alongside espresso-core. The test still launches an activity with ActivityScenarioRule; only the interactions after the WebView boundary use onWebView(), findElement(), and webMatches().

Start with a screen whose HTML exposes stable IDs and whose page state is deterministic. JavaScript must be available for Espresso-Web atoms; forceJavascriptEnabled() can enable it during the test, but the call may reload the WebView, so run it before selecting DOM nodes.

1. Add Espresso-Web to the app module's instrumented test dependencies.

   build.gradle.kts

   val espressoVersion = "3.7.0"
    
   dependencies {
       androidTestImplementation(
           "androidx.test.espresso:" +
               "espresso-core:$espressoVersion"
       )
       androidTestImplementation(
           "androidx.test.espresso:" +
               "espresso-web:$espressoVersion"
       )
   }

   Use the project's existing version catalog when it already manages AndroidX Test versions. Keep espresso-core and espresso-web on the same release.
   Related: How to configure an Android project for Espresso

2. Target stable DOM IDs in the page loaded by the WebView.

   <form id="checkout-form">
     <input id="email" type="email" />
     <button id="submit" type="submit">Submit</button>
   </form>
   <p id="receipt"></p>

   Locator.ID selects HTML element IDs, not Android resource IDs. Use withId(R.id.checkout_webview) separately when the activity contains more than one WebView.

3. Create the Espresso-Web test class under the app module's androidTest source set.

   WebViewCheckoutTest.kt

   package com.example.app
    
   import androidx.test.espresso.matcher.ViewMatchers.withId
   import androidx.test.espresso.web.assertion.WebViewAssertions.webMatches
   import androidx.test.espresso.web.sugar.Web.onWebView
   import androidx.test.espresso.web.webdriver.DriverAtoms.clearElement
   import androidx.test.espresso.web.webdriver.DriverAtoms.findElement
   import androidx.test.espresso.web.webdriver.DriverAtoms.getText
   import androidx.test.espresso.web.webdriver.DriverAtoms.webClick
   import androidx.test.espresso.web.webdriver.DriverAtoms.webKeys
   import androidx.test.espresso.web.webdriver.Locator
   import androidx.test.ext.junit.rules.ActivityScenarioRule
   import androidx.test.ext.junit.runners.AndroidJUnit4
   import androidx.test.filters.LargeTest
   import org.hamcrest.Matchers.containsString
   import org.junit.Rule
   import org.junit.Test
   import org.junit.runner.RunWith
    
   @RunWith(AndroidJUnit4::class)
   @LargeTest
   class WebViewCheckoutTest {
    
       @get:Rule
       val activityRule =
           ActivityScenarioRule(WebCheckoutActivity::class.java)
    
       @Test
       fun submittingEmailShowsReceipt() {
           onWebView(withId(R.id.checkout_webview))
               .forceJavascriptEnabled()
               .withElement(findElement(Locator.ID, "email"))
               .perform(clearElement())
               .perform(webKeys("buyer@example.com"))
               .withElement(findElement(Locator.ID, "submit"))
               .perform(webClick())
               .withElement(findElement(Locator.ID, "receipt"))
               .check(
                   webMatches(
                       getText(),
                       containsString("buyer@example.com")
                   )
               )
       }
   }

4. Replace the sample activity, WebView resource ID, DOM IDs, input value, and receipt assertion with values from the app under test.

   If a click loads another document, call reset() before selecting elements on the new page. Keep the final assertion on the rendered DOM state that proves the hybrid screen handled the input.

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

   $ ./gradlew :app:connectedDebugAndroidTest
   
   Task :app:connectedDebugAndroidTest
   Starting 1 tests on Pixel_8_API_35
   WebViewCheckoutTest > submittingEmailShowsReceipt PASSED
   Finished 1 tests on Pixel_8_API_35
   
   BUILD SUCCESSFUL in 37s

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