Crashlytics in Android Kotlin

Introduction

Crashlytics helps you find and fix app crashes quickly. It shows you what went wrong so you can improve your app.

You want to know why your app crashes on users' devices.

You want to see detailed reports of errors without asking users.

You want to improve app stability by fixing bugs fast.

You want to track crashes after releasing app updates.

You want to get alerts when new crashes happen.

Syntax

Android Kotlin

implementation 'com.google.firebase:firebase-crashlytics-ktx:18.4.1'

// Initialize Crashlytics in your Application class
FirebaseCrashlytics.getInstance().setCrashlyticsCollectionEnabled(true)

// Log a custom message
FirebaseCrashlytics.getInstance().log("User clicked button")

// Record a non-fatal exception
FirebaseCrashlytics.getInstance().recordException(Exception("Test error"))

Add the Crashlytics dependency in your app's build.gradle file.

Enable Crashlytics collection to start sending crash reports.

Examples

This logs a message to Crashlytics to help track app events before a crash.

Android Kotlin

FirebaseCrashlytics.getInstance().log("App started")

This records a caught error without crashing the app, so you can see it in Crashlytics.

Android Kotlin

FirebaseCrashlytics.getInstance().recordException(Exception("Network error"))

This disables sending crash reports, useful for debugging or user privacy.

Android Kotlin

FirebaseCrashlytics.getInstance().setCrashlyticsCollectionEnabled(false)

Sample App

This simple app enables Crashlytics, logs a message, and records a caught division by zero error without crashing.

Android Kotlin

import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import com.google.firebase.crashlytics.FirebaseCrashlytics

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(android.R.layout.simple_list_item_1)

        // Enable Crashlytics collection
        FirebaseCrashlytics.getInstance().setCrashlyticsCollectionEnabled(true)

        // Log a message
        FirebaseCrashlytics.getInstance().log("MainActivity created")

        // Simulate a caught error
        try {
            val result = 10 / 0
        } catch (e: Exception) {
            FirebaseCrashlytics.getInstance().recordException(e)
        }
    }
}

Important Notes

Always test Crashlytics integration by forcing a test crash or recording exceptions.

Crash reports appear in the Firebase console after users run your app.

Use logs and custom keys to add more info to crash reports.

Summary

Crashlytics helps track and fix app crashes automatically.

Enable it by adding the dependency and initializing in your app.

Use logging and exception recording to get detailed crash info.

Practice

1. What is the main purpose of Crashlytics in an Android app?

easy

A. To automatically track and report app crashes

B. To improve app UI design

C. To manage app navigation

D. To optimize app performance speed

Solution

1. Step 1: Understand Crashlytics functionality

   Crashlytics is a tool designed to detect and report app crashes automatically.

2. Step 2: Compare options with Crashlytics purpose

   Only To automatically track and report app crashes matches the core function of Crashlytics, which is crash tracking and reporting.

3. Final Answer:

   To automatically track and report app crashes -> Option A

4. Quick Check:

   Crashlytics = crash tracking [OK]

Hint: Crashlytics = crash reports automatically [OK]

Common Mistakes:

• Confusing Crashlytics with UI or navigation tools
• Thinking Crashlytics improves app speed
• Assuming Crashlytics manages app content

2. Which of the following is the correct way to add Crashlytics dependency in your app's build.gradle file?

easy

A. apply plugin: 'com.google.firebase.crashlytics'

B. compile 'com.google.firebase:firebase-crashlytics:18.3.7'

C. implementation 'com.google.firebase:firebase-analytics:18.3.7'

D. implementation 'com.google.firebase:firebase-crashlytics:18.3.7'

Solution

1. Step 1: Identify correct dependency syntax

   Modern Gradle uses 'implementation' to add dependencies, not 'compile' which is deprecated.

2. Step 2: Match Crashlytics dependency artifact

   The correct artifact for Crashlytics is 'firebase-crashlytics', not 'firebase-analytics'.

3. Final Answer:

   implementation 'com.google.firebase:firebase-crashlytics:18.3.7' -> Option D

4. Quick Check:

   Use implementation + firebase-crashlytics [OK]

Hint: Use 'implementation' with firebase-crashlytics artifact [OK]

Common Mistakes:

• Using deprecated 'compile' keyword
• Confusing Crashlytics with Analytics dependency
• Using plugin apply instead of dependency line

3. Given this Kotlin code snippet, what will Crashlytics record when the app crashes?

try {
  val result = 10 / 0
} catch (e: Exception) {
  Firebase.crashlytics.recordException(e)
}

medium

A. Crashlytics records the division by zero exception

B. No crash recorded because exception is caught

C. App will crash without any report

D. Crashlytics records a null pointer exception

Solution

1. Step 1: Analyze exception handling

   The division by zero throws an ArithmeticException, which is caught in the catch block.

2. Step 2: Check Crashlytics exception recording

   The caught exception is passed to Firebase.crashlytics.recordException(e), so Crashlytics logs it even without app crash.

3. Final Answer:

   Crashlytics records the division by zero exception -> Option A

4. Quick Check:

   recordException logs caught exceptions [OK]

Hint: recordException logs caught errors even if app doesn't crash [OK]

Common Mistakes:

• Thinking caught exceptions are ignored by Crashlytics
• Assuming app crashes without report
• Confusing exception types

4. You added Crashlytics to your app but no crash reports appear in the Firebase console. What is a common mistake causing this?

medium

A. Adding Crashlytics dependency in the wrong module

B. Using the wrong package name in build.gradle

C. Not initializing Firebase in the Application class

D. Calling recordException outside a try-catch block

Solution

1. Step 1: Check Firebase initialization

   Firebase must be initialized early, usually in the Application class, for Crashlytics to work.

2. Step 2: Evaluate other options

   Wrong package name or dependency module can cause issues but the most common is missing Firebase initialization.

3. Final Answer:

   Not initializing Firebase in the Application class -> Option C

4. Quick Check:

   Initialize Firebase early for Crashlytics [OK]

Hint: Always initialize Firebase in Application class [OK]

Common Mistakes:

• Forgetting FirebaseApp.initializeApp(context)
• Misplacing dependencies in modules
• Assuming recordException needs try-catch

5. You want to log a custom message and a user ID to Crashlytics before a crash happens. Which code snippet correctly does this?

hard

A. Firebase.crashlytics.log("User clicked the crash button")
throw RuntimeException("Test crash")
Firebase.crashlytics.setCustomKey("userId", "12345")

B. Firebase.crashlytics.setCustomKey("userId", "12345")
Firebase.crashlytics.log("User clicked the crash button")
throw RuntimeException("Test crash")

C. throw RuntimeException("Test crash")
Firebase.crashlytics.setCustomKey("userId", "12345")

D. Firebase.crashlytics.recordException(RuntimeException("Test crash"))
Firebase.crashlytics.setCustomKey("userId", "12345")

Solution

1. Step 1: Understand Crashlytics logging order

   Custom keys and logs must be set before the crash to be included in the report.

2. Step 2: Check code snippet order

   Firebase.crashlytics.setCustomKey("userId", "12345") Firebase.crashlytics.log("User clicked the crash button") throw RuntimeException("Test crash") sets the user ID and logs the message before throwing the crash, so data is captured correctly.

3. Final Answer:

   Set custom key and log before crash throw -> Option B

4. Quick Check:

   Set keys and logs before crash [OK]

Hint: Set keys/logs before crash throw to capture data [OK]

Common Mistakes:

• Setting keys after crash throw (too late)
• Using recordException instead of throwing crash
• Not logging custom messages