March 12, 2020

Challenges of testing Angular applications

Scriptless Testing

So you’ve decided to build a new web application – great! Whether you’re revamping your main website or creating a portal that customers can access individually, choosing how to build your application is a critical choice that you’ll need to make early on in the development process.

In general, there are two types of web applications that you can build today: traditional web applications and single page applications (SPAs). While traditional web applications perform the majority of the application logic on the server, SPAs perform most of the UI logic in a web browser. One of the most common SPAs is Angular, which has continued to grow in popularity amongst developers in many industries.

While Angular and other SPAs offer certain advantages when it comes to application development, they also present some unique challenges when it comes to testing them effectively. This post will go into some of the main factors to consider when testing Angular applications in more detail, as well as discuss the tooling available to address these issues.

Why use Angular in the first place?

Before discussing the challenges of testing Angular applications, it’s important to go into a bit of background as to why companies would choose to build their application with Angular in the first place. When we understand the advantages of using Angular, it will shed more insight into why testers feel the need to approach testing these types of applications differently.

First, Angular and other SPAs are generally easy to deploy. Normally it’s a much smaller set of files to handle, especially when compared to more traditional server-side rendered applications.

Another advantage is that SPAs like Angular often show higher levels of performance due to the fact that they require less bandwidth and full-page reloads. After the initial page load, only data gets sent to the server and over the wire (as opposed to sending the entire page’s HTML continuously). This SPA architecture offers a much better user experience since page load times are often much faster.

While these changes are often visible and easily deployable on the front end, that is not the case for the back end of the application. This leads to some of the major challenges that QA professionals face when creating and maintaining tests for Angular applications and other SPAs.

Generate Component

Example of building an Angular application

Challenges of Angular testing

There are two important challenges that testers must consider when doing Angular testing: identifying the correct elements and accounting for web components that are open-source. Let’s delve into them both:

Element identification

We already mentioned that Angular web applications only need to send data over the wire, instead of reloading completely by sending over the entire page’s HTML code. While this is a positive attribute from a user experience standpoint, it causes a lot of difficulty when trying to locate elements when building tests.

Unlike a traditional server-side rendered application, testers cannot rely on IDs to locate elements in Angular. Since applications are ultimately built by the framework and developers are putting the different components together instead of coding the application themselves, they do not have insight into the application logic in the back end. Therefore, the application is difficult to understand when creating automated tests for the application later on in development.

Angular pages’ ability to update and reshape their content without reloading ultimately presents a lot of issues when it comes to UI automation. It’s difficult to locate elements on the page and detect when changes happen, especially when these elements appear and disappear continuously on the screen.

Accounting for open-source web components

Another benefit of Angular and other SPAs is that they let you use open-source components in their applications more easily. For example, let’s say a developer wanted to embed a video onto their site and add the ability to click and stream that video on that web page. Working in Angular, a developer would have the option to choose a pre-made, open-source component that he or she can add simply to the application. This ability to add different functionalities simply makes Angular even more beneficial when creating applications, not just when deploying them.

A popular example of dealing with open-source components is when Salesforce plugins put Shadow DOMs inside their web pages. Shadow DOM can be very beneficial to use, as it prevents elements within the Shadow DOM tree from being manipulated in an unintended way by outside code. This unique way of encapsulating web components, however, can present significant problems when tests suddenly start breaking.

Yet since the developer did not create this component on his or her own, it’s difficult to figure out how to interact with these components, making them all the more difficult to test. In the case of Shadow DOM, it is often injected into web components, whether it’s Salesforce plugins or Angular and React pages, without companies even knowing it. While companies won’t necessarily feel the effects of this when initially building a web application, this causes issues to arise when it’s time to start automated testing before releasing new features or updates. Tests can start breaking suddenly and neither the tester nor the developer will know how to fix the issue.

How codeless test automation can help

Identifying complex elements and interacting with web components are essential for creating a scalable and reliable test automation framework. Yet many popular, code-based automation testing tools on the market cannot accomplish these tasks in a simple or efficient manner. Using code-based tools like Selenium, companies need to spend a lot of time and effort building and maintaining their automated tests. When it comes to web components encapsulated by Shadow DOM, Selenium cannot even support this natively.

Codeless test automation presents a great alternative to code-based solutions when it comes to creating a robust automation testing environment that is completely technology-agnostic. In the case of TestCraft, in particular, our tool is based on Selenium. Yet TestCraft’s ability to easily test any web application regardless of the programming language or framework makes Selenium test automation even more comprehensive.

One major advantage of TestCraft’s codeless Selenium platform that helps with Angular testing is our AI-based, self-healing technology. By assigning different weights to various attributes of web elements, our platform can identify virtually any web element to ensure that tests don’t break (although to clarify, testers will need to update tests when there are changes in the tests’ logic). This means that even on SPAs and when companies make changes to the application, tests will continue to stay reliable and resilient.

TestCraft Weights

How TestCraft assigns different weights to different web component attributes

Think ahead with codeless testing tools

There is a lot to think about when building or updating your company’s application, from user experience issues to keeping up your company’s competitive edge. Testing these applications should not be a headache that managers think about with dread.

With a codeless testing tool that is designed to support a wide range of coding languages, testing frameworks, and other challenges, you are uniquely positioned to deal with any upcoming obstacle before it becomes an issue. From dealing with Shadow DOMs to testing Angular applications, leveraging a codeless testing tool can help QA managers best prepare for future application development and improvement.