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Importance of End-to-End Testing

How important end-to-end testing (E2E) is? E2E determines whether an application’s flow is as expected from start to end. Click now to learn.

January 7, 2021

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How important end-to-end testing (E2E) is? E2E determines whether an application’s flow is as expected from start to end. Click now to learn.
What is E2E Testing? Here’s a 30-second introduction: Modern applications are interconnected and integrated with various systems.

This increases the complexity of their entire workflow. If the systems outside of the enterprise experience an error or malfunction, it can have an adverse impact on the functioning of the application with which they are linked. That’s where E2E or end-to-end testing comes into play. In a competitive market where there’s no shortage of applications for an enterprise, it’s necessary to perform E2E testing on applications to ensure a good user experience.

What Is End-to-End Testing? 

End-to-end testing utilizes real-time simulation procedures to determine whether an application’s flow is as expected from start to end. Software testers use it to capture bugs and errors through the various stages of the software development lifecycle and rectify them most efficiently. 

For example, an E2E test for an ecommerce app would include actions from a user’s perspective. Steps might include:

  1. Logging into the app
  2. Viewing different product pages
  3. Selecting an item and placing it in the checkout cart
  4. Going back to the product page to ensure the right price is displaying
  5. Placing the order
  6. Adding certain items to the wish list
  7. Logging out of the app

The tester should check the order placement process to ensure the options to pay are appearing as expected. Plus, they should check the functionality of the third-party integrations for net banking and any online wallets the app includes for payment purposes. Further, the total prices, applicable taxes, payment confirmation, and notification of the payment processing should be verified.

Activities Required for End-To-End Testing 

Here are the key activities that are a must for E2E testing:

  • Analyzing the requirements thoroughly before beginning the test.
  • Following all the prerequisites when setting up the test environment.
  • Assessing the minimum and recommended configurations of the required hardware and software.
  • Examining the main system plus the attached subsystems.
  • Briefing the roles and responsibilities of all systems involved.
  • Creating a list of testing methods.
  • Writing the descriptions of the testing standards to be followed.
  • Designing test cases along with tracing the requirement matrix.
  • Securing the output results and entering data before conducting system tests.

Types of End-to-End System Testing

There are two main types of end-to-end testing: 

Vertical: This E2E testing method involves conducting tests in hierarchical order from one layer to another (API, front end, etc.). The tester tests each component of an application or system from start to end to validate their quality. This type of E2E testing is normally used to test the components in computing systems that don’t involve interfaces or users. 

Horizontal: Horizontal E2E testing involves going horizontally across the context of different applications. It can also easily take place in a single enterprise resource planning application. This method’s end goal is to confirm the behavior and the flow of an app to see if a user can navigate it without any defects or hiccups. Compared to vertical E2E testing, horizontal testing doesn’t require technical knowledge because the tester doesn’t need to apply a combination of white box and black box testing. 

Errors to Target with End-to-End Performance Testing 

This software application testing methodology should be used to verify that a user can move through and use the various interaction points (form, button, etc.). The tester should also look for potential bugs in the application's return path in terms of user-initiated data transformations and the individual elements. Smartly conducted E2E tests also look for browser or JavaScript errors. Moreover, the API's functionality and blocks of code can also be tested during the execution process. 

However, E2E testing should not repeat the steps of API or unit testing. The latter is meant to test business logic. Essentially, API tests verify that a correct response occurs for a given call. In contrast, a unit test validates that a block of code leads to the right output variables for specified input variables. 

E2E Testing Parameters 

End-to-end testing has the following parameters:

  • Weekly test progress – allows the tester to measure progress through weekly reports. Percentage scores represent the tests not conducted, conducted and failed as well as passed test cases. The tester can then compare the scores with the previous week’s report.
  • Preparation of current and planned test cases – so that the team can check the current status of the cases vs. those planned on a graph. The visual representation will give a clear insight into the progress so far.
  • Defect report – reflects the “execution status” of test cases. The testing team should create one on the basis of priority and severity. Once done, the previous week’s result can be compared with the percentage of closed and open defects to measure the progress.
  • Testing environment – allows the tester to track the time allocated for E2E testing compared to the actual time spent conducting this test.

Ideal Scenarios for E2E testing

You can apply E2E testing in various scenarios. For example, developers and designers can build a list of what functions, features or UI is required. Then they can track the data flow between systems to discover inaccuracies, flaws and dependencies. Before testing, teams also need to prepare the factors (referred to as conditions) that may modify the interface options. Generally, E2E testing is conducted on completed systems and products, using each review as an exam of the finished system. 

If you detect a bug or the system’s output isn’t the same as expected, you can conduct a second test. In this scenario, the testing team must track and analyze the data to identify the problem’s source and then address the issue before performing a re-test. 

Final Word 

E2E testing plays an essential role in ensuring that application users receive a quality user experience. More than testing if a model displays or a function works correctly, examining the user experience from start to finish offers greater assurance regarding the application's workflow. It’s an affordable way to ensure your app works the way that you and users intend it to.