Tutorial: Using Logs to Identify Critical Errors with Firebase Crashlytics

1. Introduction

Goal

The aim of this tutorial is to help you understand how to use logs provided by Firebase Crashlytics to identify critical errors in your application.

What You Will Learn

• How to set up Firebase Crashlytics in your app
• How to interpret Firebase Crashlytics logs
• How to apply these logs to your bug fixing process

Prerequisites

• Basic understanding of programming
• Familiarity with the Firebase platform
• An existing Firebase project to work with

2. Step-by-Step Guide

Setting Up Firebase Crashlytics

Firstly, you need to integrate Firebase Crashlytics into your application. Follow the official Firebase Crashlytics documentation for a detailed guide on how to integrate Crashlytics with your specific platform (Android, iOS, Unity).

Understanding Crashlytics Logs

Firebase Crashlytics provides detailed reports of each crash happening in your application, including:

• The full stack trace
• The time of the crash
• The version of your app
• Information about the device

Use this information to identify patterns and common issues causing crashes in your application.

Applying Logs to Bug Fixing

Once you've identified a critical error, you can replicate the issue using the data from the crash report, fix it, and then verify the fix by looking for the absence of the same crash in subsequent reports.

3. Code Examples

Setting Up Crashlytics Logging

// Import the Crashlytics library
import com.crashlytics.android.Crashlytics;

// Initialize Crashlytics
Crashlytics.start(this);

// Log a message
Crashlytics.log("Activity started");

// Log an exception
try {
    throw new RuntimeException("Test exception");
} catch (RuntimeException ex) {
    Crashlytics.logException(ex);
}

In this example, we first import the Crashlytics library. Then, we start Crashlytics and log a simple message. Finally, we simulate an exception and log it.

4. Summary

In this tutorial, we've learned how to set up Firebase Crashlytics, understand its logs, and apply this knowledge to debug and fix critical errors in your application. You should now be able to use this powerful tool to significantly improve the stability of your app.

5. Practice Exercises

Exercise 1

Set up Firebase Crashlytics in a basic Android app and simulate a crash. Check the Firebase console to see if the crash is reported.

Exercise 2

Log custom messages and non-fatal exceptions in your app. Check the Firebase console to see if these logs appear.

Exercise 3

Identify a crash using the Firebase console, replicate it in your app, fix the issue, and verify the fix.

Tip: Remember to use the detailed information provided by Crashlytics logs, such as the full stack trace and the device info, to help identify and fix issues.