Common Espresso Issues and Solutions

1. Flaky UI Tests

Espresso tests fail intermittently without code changes.

Root Causes:

• Asynchronous operations not properly synchronized.
• UI animations interfering with test execution.
• Tests depending on hardcoded delays instead of proper wait conditions.

Solution:

Disable animations before running tests:

adb shell settings put global window_animation_scale 0adb shell settings put global transition_animation_scale 0adb shell settings put global animator_duration_scale 0

Use Espresso’s built-in synchronization:

onView(withId(R.id.button)).perform(click());

Avoid using Thread.sleep() for delays. Instead, use IdlingResource:

IdlingRegistry.getInstance().register(idlingResource);

2. View Not Found Errors

Tests fail because a view cannot be located.

Root Causes:

• UI hierarchy not fully loaded when the test runs.
• Incorrect ViewMatcher selectors.
• Multiple views matching the same selector.

Solution:

Use waitForIdleSync() to ensure UI stability:

InstrumentationRegistry.getInstrumentation().waitForIdleSync();

Ensure views have unique identifiers:

onView(withId(R.id.unique_view_id)).perform(click());

Use a more specific matcher to select the correct view:

onView(allOf(withText("Submit"), isDisplayed())).perform(click());

3. Dependency Conflicts with Espresso

Espresso tests fail due to Gradle dependency issues.

Root Causes:

• Incompatible versions of Espresso and AndroidX libraries.
• Conflicts between Espresso and other UI testing frameworks.
• Missing required dependencies.

Solution:

Ensure the correct dependency versions in build.gradle:

dependencies {  androidTestImplementation "androidx.test.espresso:espresso-core:3.5.1"  androidTestImplementation "androidx.test.ext:junit:1.1.5"  androidTestImplementation "androidx.test:runner:1.5.2"}

Force resolution of conflicting dependencies:

configurations.all {  resolutionStrategy.force "androidx.test:core:1.5.0"}

Exclude conflicting dependencies if needed:

androidTestImplementation("androidx.test.espresso:espresso-contrib:3.5.1") {  exclude module: "espresso-core"}

4. Incorrect Test Assertions

Assertions fail even when the expected UI state is correct.

Root Causes:

• Assertions executed before UI updates are complete.
• Wrong matchers used for expected values.
• Incorrect test setup leading to unintended side effects.

Solution:

Use Espresso’s onView() assertion with proper synchronization:

onView(withId(R.id.textView)).check(matches(withText("Hello World")));

Use assertThat() for validating non-UI values:

assertThat(actualText, is("Expected Value"));

Ensure test state is reset before each test using @Before:

@Beforepublic void setUp() {  ActivityScenario.launch(MainActivity.class);}

5. Performance Issues in Espresso Tests

Test execution is slow, causing extended run times.

Root Causes:

• Excessive logging slowing down test execution.
• Unnecessary UI interactions increasing test duration.
• Slow Gradle builds due to redundant dependencies.

Solution:

Disable verbose logging during test execution:

adb shell setprop log.tag.TESTING DEBUG

Use direct UI interactions instead of navigation through multiple screens:

onView(withId(R.id.target_button)).perform(click());

Optimize Gradle builds by enabling parallel execution:

org.gradle.parallel=true

Best Practices for Espresso Testing

• Disable animations before running tests to reduce flakiness.
• Use IdlingResource for handling async operations.
• Ensure unique view identifiers to prevent selection conflicts.
• Regularly update dependencies to avoid compatibility issues.
• Run tests on real devices in addition to emulators for accurate results.

Conclusion

By troubleshooting flaky tests, view synchronization problems, dependency conflicts, incorrect assertions, and performance bottlenecks, developers can ensure robust UI testing with Espresso. Implementing best practices improves test reliability and reduces execution time.

FAQs

1. Why do my Espresso tests fail intermittently?

Ensure proper UI synchronization, disable animations, and use IdlingResource instead of Thread.sleep().

2. How do I fix Espresso view not found errors?

Wait for UI stability using waitForIdleSync(), ensure views have unique IDs, and use more specific matchers.

3. Why do I get dependency conflicts when using Espresso?

Check for mismatched AndroidX and Espresso versions, force correct dependencies, and exclude redundant modules.

4. How can I improve Espresso test performance?

Reduce unnecessary UI interactions, disable verbose logging, and enable parallel Gradle builds.

5. Why are my assertions failing even when the UI state is correct?

Ensure UI updates are complete before assertions, use appropriate matchers, and reset test state before each test.