A Complete Guide to End-to-End Testing

Verifying the optimal performance of the application’s components allows hidden bugs and faults to be easily identified. The testers can also observe the user’s responses to the software features. 

In this article, you will learn about the importance of the End-to-End (E2E) testing process and its benefits. You can follow the testing process to examine your software successfully. In addition, the end-to-end testing example explains the procedure’s application. 

Let’s begin by looking into the end-to-end testing definition. 

What is End-to-End Testing? 

The end-to-end testing definition is simply a procedure performed on complex products. This testing confirms that the application operates as expected via all interacting components. Hence, the user experience is simulated from one end to another. 

This method validates the integrity of the information shared within the system. The software application subjected to this technique contains several sub-components dependent on each other. The system can be prone to failure if one of these subcomponents fails in operation. 

All operations possible within the system are checked in testing the software application. These include communication with the hardware devices, database applications, network connectivity, and other dependent processes. These components can only be tested after the system has confirmed its functions. Thus, end-to-end testing seeks to mitigate the risk of failure and avoid such occurrences. 

In addition, it verifies if a user will encounter a bug or interference while navigating through the system. It can also confirm the quality of components that do not include user operations or interfaces. These validations are essential for ensuring confidence in the software application.

Why is end-to-end testing important? 

This testing practice makes it easier to identify faults in the system before releasing the product or its update to the user. It is possible because the detailed test coverage expands beyond the system units to test the interacting components and data shared outside the boundary. 

In addition, it further confirms that the software meets expectation, limit risks in various scenarios and provides opportunities for improvement where necessary. 

Here are some of the applications of end-to-end testing. 

Multi-tier system 

Firstly, E2E testing must be incorporated to verify communications between distinct tiers for complex applications. This is necessary for testing the work flowing through multiple tiers. 

Backend 

Then, the database and layers not visible to users of an application can be accessed using end-to-end testing. This is important because the functionality of these backend layers contributes to the application’s ability. 

Consistent user experience 

The software must provide users with a consistent experience across all devices, platforms, and working environments. This can be verified through front-end testing of the software product. 

Distributed environment 

Lastly, applications dependent on a cloud environment or service-oriented architecture require repeatedly end-to-end testing for multiple components.

Benefits of End-to-End Testing 

The end-to-end testing procedure has allowed to expand test coverage during application testing. Testing all related operations quickens the discovery of bugs and increases the accuracy of the application while reducing the cost and time taken to release the product. 

The advancement in technology has given rise to subsystem interactions within modern software. The following should be carried out to avoid failures initiated by subsystem components. 

1. First, expand the areas to be tested. 
2. Next, validate the flow within subcomponents. 
3. Finally, identify issues within subsystems. 

Challenges of End-to-End testing? 

Although end-to-end testing comes with benefits, there are challenges faced during the testing procedure. This method takes time and is complex to design due to imitating real-world scenarios. Also, the user objectives must be well understood to test the application successfully. 

Time Consuming 

To begin with, the several workflow paths in an application lengthen the time taken for testing. The written test cases require a complete understanding of the product. Organizations reserve end-to-end testing for critical user workflows rather than testing all workflow paths. 

Understanding User Goals 

At the business analysis phase, understanding user goals is one of the challenges faced by the testing team. The software development teams must gather the user’s perception of the software and understand the context of use of the system. 

This informs their decision on testers because the expensive cost of research, which makes the software testing team recycle the same set of sabe users, can affect the accuracy of the user goals obtained from the test. 

Difficult to design 

Lastly, designing end-to-end tests can be complex due to the several components. An end-to-end testing example is running a web application on many browsers. Specifications for the browser test cases can vary for different scenarios. This can lead to spending beyond budget. Also, end-to-end testing may not produce quick responses when needed. 

Having an integrated environment for the test 

To run a successful E2E test, all the components (including third party services) must be integrated. More often than not, it is often a challenge to have an integrated environment for test execution. 

End-to-End Testing Process 

The process for an end-to-end test requires an analysis of the test to be carried out. Studying the systems and subsystems of the application will determine the design of the test. Below are the steps required to complete an end-to-end test. 

1. To begin with, study the requirements of the software. Get a good understanding of the application’s functions and workflow.
2. Then, prepare the test environment in alignment with the hardware and software requirements.
3. Next, understand the system and subsystems. Highlight the responses. 
4. Now, define the methods necessary for testing these responses. These include end-to-end testing tools. 
5. Afterward, create the test cases using the established testing standards. 
6. Execute the defined test. In addition, perform exploratory testing to cover other areas undefined in the pre-determined test. 
7. Finally, save and study the test results. 

Three Categories of Design Framework under E2E testing 

The E2E testing design framework entails three parts which are building user functions, conditions, and test cases. Let’s take a brief look at them. 

Build user functions 

Identify features of the software and all the existing subsystems. Then, take note of the input and output data, action, and the relationships between them. Determine if the user functions are independent or reusable. For example, in a scenario where you want to transfer money from your bank account to a third-party subsystem, user functions will include the following: 

1. Login into the banking application system 
2. Check the current balance in the account 
3. Transfer money to the third-party subsystem 
4. Check the current balance after the transfer
5. Logout of the system

Build conditions 

Ensure you build conditions peculiar to every user function. These could be data conditions, timing, and sequence. For example, during login, check for conditions like: 

• Invalid Username and password 
• Checking Password strength 
• Checking for the validity of Username and password 
• Checking error messages 

While checking the balance amount, the following conditions can be built: 

• Check for an error message if the transfer amount is more than the current balance
• Check the current balance 24 hours after the transfer is made to another bank

Build test scenarios/cases

Build specific test cases and scenerios for pre-defined user functions. Every condition must have a particular test assigned to it. In this banking system, test scenarios include:

• Transfer money to a third-party bank within the same locality 
• Make an eCommerce transaction with bank details 
• Pay international banks from banking application

Metrics for End-to-end Testing 

There are metrics relevant to this testing technique. These are test case preparation status, weekly progress tracking, defect details and environment availability. 

Test Case Preparation status: 

This metric explains the positions of the prepared test cases compared with the planned test cases. It reveals if suitable cases are being designed to test the features. 

Weekly Progress Tracking: 

Test progress showing the percentage of completed tests on a weekly basis. In addition, the test provides details about the executed test cases, non-executed test cases, passed, failed, valid and invalid test cases.

Defects details: 

Every week, the percentage of open and closed defects should be identified based on priority. Managers and testers require this metric to monitor bugs and resolve them. 

Environment availability: 

The time spent on testing is compared to the proposed time scheduled. This evaluates time lost or gained during testing. 

End-to-end testing example 

There are different applications of this testing procedure. An end-to-end testing example is software serving as a flight ticketing system. 

1. First, it would involve entering the software link/URL, then logging into the system with valid user credentials. 
2. Entering the source and destination, date of journey, travel class, and transport options.
3. Selecting the preferred option and number of tickets and make payment using the same application 
4. The flow wraps up with a copy of the ticket displayed for printout to the user. Another copy is sent to their email address automatically. 

End-to-End Testing Tool 

The advancement in technology has made end-to-end testing tools available for this methodology. Some of these tools include: 

• testRigor 
• QA Wolf 
• Autify 
• Mabl 
• Cypress 
• Katalon Studio 

Katalon Studio 

This tool is widely accepted in the industry. It delivers world-class digital experiences using AI for planning, and executing automated tests. 

Features 

• Instant mobile and web test environments 
• Real-time visibility and actionable insights 
• Quality command center 
• Create tests in one minute 
• Align requirements with a testing strategy 
• Translates user interactions to autonomous test data and cases with minimal tester efforts. 

How to implement End to End Testing 

Implementing an end-to-end testing process begins with designing end-to-end scenarios. This step is succeeded by manual testing until it is appropriate to automate. Below are details on the steps involved.

Designing end-to-end test cases 

To begin with, evaluate the requirements needed to confirm if the testing result is achieved. Then, create environments suitable for testing and establish the processes of the systems and subsystems. For example, the login page for a banking software includes the following: 

1. Enter your Username and password
2. Click log in or Signup as a new user 
3. Click ‘Forgot Password to reset your password. 

Now, choose the required testing tools and structure. Highlight the necessities for every designed test case. Before implementing, the testing process, list the system output and input data. These preparation steps will guarantee successful testing. 

Manual end-to-end testing 

A human tester carries out a manual testing procedure for the user software. This enables the tester to determine the functions operating properly while writing the test cases. User interaction paths that are hidden can be identified during manual testing. This information will benefit the automation of the test cases in the future. 

The two methods of manual testing are horizontal and vertical end-to-end testing. 

Horizontal E2E testing involves examining the entire application user paths; software developers must create established test workflows to review several subsystems in this case. This could be a simultaneous database, UI, and email integration test. 

In addition, horizontal E2E testing occurs within a single application and is used across the context of many applications. An example is a web-based app of an eCommerce system which includes accounts, shipping details, product inventory status, and many more. 

Unlike Horizontal E2E testing, vertical end-to-end testing allows the application to be tested layer by layer in sequential and hierarchical order. It is often used for testing critical components of complex systems which does not involve interfaces or users. Each component of the product is tested from start to finish. 

Bugs are easily identified and discovered with this operation. Hence, they precede horizontal end-to-end testing. 

Automated end-to-end testing 

Lastly, automated end-to-end testing is advised for extensive test processes where user interface actions depend on each other. Automating the testing procedure with Katalon Studio will save time due to the test system’s complexity. The test cases are integrated with an automation testing tool for this method. 

This option discovers bugs faster because the test code bases are checked automatically when new codes are added. Automation of end-to-end testing should be encouraged due to the increased rate at which features are added to the software.

Conclusion 

This article reviewed the End-to-end testing method on software products before they are released to users. This testing method is crucial for confidence in the application and to assist the software development team in identifying malfunctioning operations. 

In addition, E2E can be time-consuming because it requires a proper understanding of all workflows within the software application. 

FAQs 

What is end-to-end testing, for example? 

An end-to-end testing example is running an application on different web browsers with various specifications. 

What is an end to end testing in QA? 

It is a method for testing software products from workflow start to finish. 

What is end-to-end testing and system testing? 

System testing is relevant only to the software system, while an end to end testing reviews the software’s workflow behaviour.