How do you debug mobile web app offline and online behavior?

2 Use Service Workers

Service workers are JavaScript files that run in the background and act as proxies between your app and the network. They can intercept and modify network requests, cache resources, and provide offline functionality. Service workers are essential for building progressive web apps (PWAs), which are web apps that can work offline, load fast, and behave like native apps. To use service workers, register them in your app's main JavaScript file, and then write the logic for handling network events, caching strategies, and offline fallbacks in the service worker file. Use Chrome DevTools to inspect and debug your service workers, as well as test how your app works offline by checking the Offline checkbox in the Network panel.

3 Use Local Storage

Local storage is a web API that allows you to store data in the browser, without relying on the server or cookies. Local storage can persist data across sessions, tabs, and reloads, and can store up to 5 MB of data per origin. Use local storage to store user preferences, settings, form data, or any other data that you want to keep offline and sync online later. To use local storage, use the localStorage object in JavaScript, which provides methods for setting, getting, removing, and clearing data. Also use Chrome DevTools to view and edit your local storage data in the Application panel.

4 Use Debugging Tools

In addition to Chrome DevTools, there are a number of other debugging tools available to help debug mobile web app behavior both offline and online. Remote Debugging allows you to debug your app on a remote device or emulator with tools like Safari Web Inspector, Firefox Remote Debugging, or Android Studio. Debugging Extensions are browser extensions that provide additional features for debugging, such as Lighthouse which audits performance, accessibility, and PWA readiness or React Developer Tools which lets you inspect and modify React components and state. Debugging Libraries are JavaScript libraries that provide debugging functions or utilities such as console.log which prints messages to the console or debug which lets you create and toggle debug logs with namespaces and colors.

5 Use Testing Tools

Use testing tools to automate and simulate your app's offline and online behavior, and check for errors, bugs, or inconsistencies. Testing Frameworks such as Mocha, Jasmine, or Jest provide a structure and syntax for writing and running tests. Additionally, Testing Libraries like Chai, Sinon, or Enzyme offer specific functions or assertions for testing. Furthermore, Testing Services such as BrowserStack, Sauce Labs, or Firebase Test Lab offer cloud-based testing platforms or devices. Debugging mobile web app offline and online behavior may be challenging; however, with Chrome DevTools, service workers, local storage, debugging tools, and testing tools it is achievable. By utilizing these tools and techniques, your app will become more reliable and user-friendly in various network scenarios.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?