Learn Testing & Debugging

Firebase Crashlytics is a lightweight, real-time crash reporting tool that helps you track, prioritize, and fix stability issues. To use it:

1. Add the Crashlytics SDK to your app via Gradle.

2. Initialize Firebase in your Application class.

3. Force a test crash to verify setup.

4. View crash reports in the Firebase Console, including stack traces, device info, and custom logs.

Espresso is Google’s UI testing framework for Android. It allows developers to write concise, reliable tests that simulate user interactions like clicks, typing, and scrolling. Espresso automatically synchronizes with the UI thread, reducing flakiness and making tests faster and more stable

JUnit is a unit testing framework for Java and Kotlin used to validate individual components of your Android app. It supports annotations like @Test, @Before, and @After, and integrates with Android Studio for local JVM-based testing. JUnit is ideal for testing business logic, utility classes, and pure functions

Unit testing runs on the JVM and tests isolated logic without Android dependencies. Instrumentation testing runs on devices or emulators and validates UI interactions, system components, and integration flows

Use Log.e("TAG", "Error message") to print errors. Filter logs by tag or priority (e.g., adb logcat MyApp:D *:S) to isolate relevant messages. Logcat helps trace stack traces and runtime exceptions during app execution

LeakCanary is a memory leak detection library for Android. It automatically monitors your app for retained objects and alerts you when a leak is detected, helping you fix memory issues before they affect users.

• Use JUnit for logic, Espresso for UI.

• Disable animations during UI tests.

• Mock dependencies with Mockito.

• Run tests across multiple API levels.

• Integrate tests into CI/CD pipelines

@Test
fun testGreetingButton() {
onView(withId(R.id.name_field)).perform(typeText("Steve"))
onView(withId(R.id.greet_button)).perform(click())
onView(withText("Hello Steve!")).check(matches(isDisplayed()))
}

This test types a name, clicks a button, and verifies the greeting appears