Fixing Kotlin Espresso Test Fails: A Complete Guide

When writing UI tests in Android using Kotlin and Espresso, failures are a common frustration. Whether you’re dealing with timing issues, wrong view selectors, or misconfigured test environments, Espresso test failures can slow down development. This Kotlin Espresso Test Fails Troubleshooting Guide will walk you through the most frequent causes of failure and how to resolve them effectively.

What is Espresso?

@Test
fun testButtonClickOpensNewActivity() {
    onView(withId(R.id.myButton)).perform(click())
    onView(withText("Welcome")).check(matches(isDisplayed()))
}

In theory, this looks simple. But often, tests like these fail in CI pipelines or even locally with errors like NoMatchingViewException or PerformException.

Common Kotlin Espresso Test Failures & Fixes

1. View Not Found (NoMatchingViewException)

onView(withId(R.id.delayedView))
    .check(matches(isDisplayed()))

Fix with IdlingResource:

IdlingRegistry.getInstance().register(yourIdlingResource)
// Run your test
IdlingRegistry.getInstance().unregister(yourIdlingResource)

2. PerformException: Error performing ‘single click’

onView(allOf(withId(R.id.myButton), isDisplayed()))
    .perform(click())

Or scroll to it:

onView(withId(R.id.myButton)).perform(scrollTo(), click())

3. Activity Not Launched or Test Setup Failure

@get:Rule
var activityRule = ActivityScenarioRule(MainActivity::class.java)

val scenario = ActivityScenario.launch(MainActivity::class.java)

4. Asynchronous Background Tasks Not Awaited

val countingIdlingResource = CountingIdlingResource("DataLoader")
countingIdlingResource.increment()
// after data load completes
countingIdlingResource.decrement()

5. Unstable Tests on CI (Flaky Tests)

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

Case Study: Test Fails Due to Delayed Fragment Load

@Test
fun testFragmentAppearsAfterClick() {
    onView(withId(R.id.btnLoadFragment)).perform(click())
    onView(withText("Fragment Loaded")).check(matches(isDisplayed()))
}

Fix: Use Idling Resource or custom delay:

@Test
fun testWithDelay() {
    onView(withId(R.id.btnLoadFragment)).perform(click())
    Thread.sleep(1000) // Not ideal, prefer IdlingResource
    onView(withText("Fragment Loaded")).check(matches(isDisplayed()))
}

Best Practice: Avoid Thread.sleep() and prefer proper synchronization.

Summary Table: Common Kotlin Espresso Test Failures

With these solutions, your Kotlin Espresso tests should become more stable, readable, and reliable across both local and CI environments.