What Is End To End Testing? Why Is It Important?

What Does End-To-End Testing Mean?

End-to-end testing is a Software testing methodology in which QA tests an application flow from start to end. In this QA validates the integration with external interfaces and ensures the functionality of the system under the testing phase. End to End testing is usually carried out after functional and System testing. End2End testing is also termed as Chain Testing. In this testing, we verify whether the flow of an application is right from the very start to finish and if it is processing as per the expectations or not. 

Reasons To Perform End-To-End Testing

In End to End testing, we test the critical functionalities such as communicating with the other systems, interfaces, database, network, and other applications. A sub-system may be different from the primary System. If any functionality of sub-systems fails, then the whole software system could damage. This is a major risk, and it can be avoided by performing End-to-End testing. It verifies the complete system flow. So E2E testing helps to detect issues in sub-systems and increases confidence in the overall software product. Hence, the purpose of End-to-End Testing is to monitor a complete system.

Few Activities That Are Included In End To End Process Are:

•  Thorough Study of end to end testing requirements

•  Setup of Test Environment and hardware/software requirements

• Prepare the list of roles and responsibilities for all systems and its  subsystems

• Testing methodology and standards

• Tracking of End to end requirements and designing of test cases

• Record and save input and output data for each system

Automated Testing: End-To-End Agile Testing Framework

End to end Testing Framework is categorized into 3 categories:-

User Functions: Following actions should be performed while building the User Functions:-

•  Listing the features of the software systems and their sub-systems.

•  For any function, keep track of the actions performed as well as Input and Output data.

•  Find the relations between different Users' functions.

•  Find out the essence of different user functions .i.e. if they are independent or are reusable.

Conditions: Following actions should be performed while building the Conditions based on User Functions:-

• For each and every user functions, a set of conditions should be prepared.
• Timing, Data conditions, and other factors that affect user functions can be considered as parameters.

Test Cases:

Following actions should be performed while building the Test Cases:-

• For every major scenario, one or more test cases should be created to test every functionality of the user functions.
• Every single condition should be enlisted as a single test case.

Difference Between Integration Testing Vs. End To End Testing

Integration Testing: In Integration testing, QA verifies that several units work together in harmony. It is just like a white box testing approach. The developer develops a single unit one by one and then integrates it with each other, and after that, test those. In black-box testing, Software is tested as an integrated module.

End to End testing: A helper robot that behaves like a user to click around the app and verify that it functions correctly. Its real-world system testing. In E2E, an application is tested with all integrated hardware/software/database/network and other interfaces.

Difference Between Unit Testing Vs. End To End Testing

Unit Testing: Unit testing is to break down the code or functionalities into smaller parts and then test those parts individually. The main purpose of E2E testing is to validate that every single unit of the software performs perfectly as designed. For Example - A function, loop, method, or statement in the program is working very well. The Developer executes this type of testing. 

End To End Testing: E2E (end-to-end) testing is a type of functional test. Unlike a unit test, we break the application down into smaller parts to test it - you're testing the entire application. E2E tests interact with your app, just like a real user. For example, you may write an E2E test which:

• Loads your site
• Clicks on the "Sign up" link
• Provides some valid details to the inputs in the registration form
• Click the "Register button."

Best Practices For Implementing E2E (End-To-End) Testing

Typical end-to-end testing can be a lot of time-consuming when performed manually and a lot complex as well. However, to ensure the smooth completion of testing and efficient cost management following are the best practices for E2E testing:-

• Test from the Perspective of an End User – In this, QA should think like a user and should focus more on features rather than how the functionalities are implemented. Acceptance testing will help you to capture the user’s point of view and test all cases accordingly.
• Limit Scenarios Involving Exception Testing – Use end-to-end testing only to capture typical user scenarios. For exception scenarios, use integration testing and unit testing.
• Risk Analysis – In Risk Analysis, we concentrate on the significant functionalities/features of an application whose failure will cause a high risk. 
• Maintain an Order – With increasing components in an application will increase the complexity in test cases, and points of failure also increase, and it becomes difficult to debug them. So with the help of unit testing and integration testing, we can fix errors that are easier to detect. 
• Manage the Environment – Make sure the system set up for running the test cases are proficient enough. Document the requirements and make sure they are run before the testing starts. An easier solution is to follow the system requirement of the main environment. 
• Setup and Teardown Optimization – Make sure that your environment is ready to start the job at a moment’s notice. Once testing is done, clear the test data so that the environment is restored to the state, it was originally, and it can be used anytime for another round of testing.

Wrapping It All Up:

I hope you learned various aspects of End to End tests like its practices, framework, activities, and the difference from others.

For any commercial release of the software, End to End verification plays a vital role as it tests the entire application in an environment like network communication, database interaction, etc. Mostly, the End to End testing is performed manually. This is not only beneficial for system validation but can also be useful for testing external integration.