As the world is growing fast in electronics, digital and mobile technologies, smartphone users are also increasing day by day and so the usage of internet data. Recent developments in new technologies are helping users to get familiar with smartphones and are helping them to find easy ways for surfing.
The term “progressive web applications” is introduced recently and it has a positive impact on mobile app development technologies. “Combining the very best qualities of the web with native apps” are termed as Progressive Web Apps.
The best part/features about native applications are push notifications and work offline feature. When compared to native apps, mobile web applications did not have the same features. Conversely, credits to web apps now all are possible. It is comprised of new Web APIs and updated web technology.

What is Progressive Web App (PWA)?

To get a clear idea about PWA we define it as- PWA (or a Progressive Web Application) is an app within your browser, displayed as a website. It does not require any downloading or installation from App Store or Google Play.
Simply, it can be defined as a website that feels like a native mobile app.

Progressive web apps will give the experience of native apps on mobile web browsers such as Chrome and Opera.
PWAs are hosted on user’s servers and can be updated without any need of issuing new updates to a play store or app store. The features of these web apps like offline working, background refresh, quick loading, push notifications, and install ability include all the capabilities like a native app offers.

How PWA Works?

The Simple structure of Progressive Web Application consists of the app shell and the dynamic/changing content.
App Shell = Static part
Content = Dynamic part

The HTML, CSS and JavaScript code combine to form the app shell, which builds the interface of the app. The interface is referred to as the static part of the app, which has the capability to display dynamic content. The app shell is cached on the device of the user and can be loaded immediately.

Content is referred to as the dynamic part; it always changes and is refreshed every time a connection is established with the internet.

One more technology exists that defines a PWA as a PWA. This technology is referred to as a Service Worker.
The service worker functions in the background as a JavaScript file. It is responsible for the offline functionality of the progressive web app through timely content caching.

Also, a simple JSON file acts as an important part and is referred to as an app manifest. It helps the device to recognize the PWA and defines how it will be displayed on the screen.

Testing Strategy for PWA?

The basic difference between a PWA and a responsive/native app is that it does not require downloading and installation like a native app from any store but it supports all features of a native app.

There are two main points that would be helpful in making a PWA:

• Application’s manifest file and the service worker.
• Considering the requirement of using https protocol.

Key Points To Keep In Mind While Testing PWA:

1. The website should be operated fully via HTTPS- Safety is one of the most important aspects in the world of PWA testing and the tester should always make sure that the site is operated via HTTPS. Lighthouse by Google Developers, Jitbit, SeoSiteCheckup, DigiCert, SSL labs, etc are the tools that we can use to test that if your website is served over HTTPS or not.
2. Web pages should be responsive: Keep in mind that your web application should show responsive behavior across all mobile and desktop devices.
3. Offline Loading: At least some or all of the most important pages should work offline. As a tester, you must ensure that your web app responds properly with proper data when it is offline.
4. Add to Home screen: You must test if the web app provides metadata for ‘Add to Homescreen’.
5. Page transitions- Transitions should be clear and smooth and should not get hinder even on slow data networks.
6. Service Worker should be validated.
7. Each page must have a URL: Each page on the web app must have a URL and take care that all the URLs must be unique.
8. Push Notifications- A tester should test push notification by considering that they do not try to be overly aggressive. Also, they should be asking for permissions to the user.
9. Functionality- The most essential part of any testing is to check the functionality of the testing entity. Functional testing covers the main areas of the app that are defined in the requirement document. Manual or PWA Automation testing can be performed by the pwa tester.

Automation tools which can be used for testing PWAs

These pwa testing tools are:

• CloudQA
• Appium
• Lighthouse by Google

Benefits of using PWA:

• No load time & Responsive
• Progressive
• App shell mode
• Size and Auto update
• Works offline
• Cross- Platform
• Cost and Time Effective

Drawbacks of PWA:

• PWAs have limited capabilities while offering integration with a smartphone or tablet’s hardware features such as NFC or Bluetooth as well as the device’s sensor package (fingerprint sensor, accelerometer, etc.).This prevents PWAs from being developed for use with mobile accessories and “wearables” like smartwatches, fitness trackers and wireless earphones.
• The wearable and other Apple devices do not fully support PWAs.
• It is not so popular in the market
• PWAs aren’t a complete solution or remedy.

Conclusion:

The growth of PWA is having a sound impact on various organizations and their online growth. We have gone through some of the principal testing techniques that are required for progressive web apps so that they closely agree to the standards and specifications.

As already seen, most of the part of PWA testing workflow depends on manual cross-browser testing. With the help of some best available tools, the burden of testing these apps manually can be significantly reduced.

Progressive web apps have enabled a new path for users to interact with websites and has allowed online businesses to involve and gain more customers. Progressive web app test is as important as building it, and time has come to take most of the advantage of this opportunity and welcome the PWA.