End To End Testing: A Complete Guide

End to end testing, also known as  e2e testing is a kind of testing methodology in which the whole software is tested from the end to end, that is from ‘start to end to check ‘, if all the functionality and the components of the software are working in the desired way?’.

It tests for the accuracy of the interaction between the components like the backend end and the front end of the software. It ensures that all parts of the software are working properly when integrated.

This testing is focused on simulating the real-life scenarios, in which the software will be operated by the user. It helps in evaluating the quality of the software developed.

Quality software is expected to provide good user experience and this is possible only if the developers test their product as a user before releasing it in the market. So that the corrective measures to prevent the customer from bringing them to the notice of the developers.

Defect detected by the user exposes the weaknesses of the testing and even they are hard to correct than correcting a software before release.

Generally, in system testing the different components of the software are tested separately either a module of code or functionality is tested ‘if it is performing well in itself?’.

What is E2E Testing?  

End to end testing plan includes the testing of the complete workflow of software from its first page to the last page, executing each feature to its complete extent. It tests the efficiency of its communication with the hardware, network, database and even with other applications.

It depends on the kind of software that it will need to communicate with other application or not but in the present world, it is very rare.

Example of software that needs to communicate with other applications is the online payment software that communicates with the bank application having the user’s account, and the debit card management systems and some other applications.

Why is E2E Testing Important?

Nowadays maximum applications work in integration with each other which means an application needs to connect with other application for the implementation of a certain feature.

end to end testing
Image Source: TechRepublic

The software is required to connect with the databases and systems available outside its environment. Because of this dependency, the workflow of an application becomes more complicated and it is possible to have some malfunctioning in this process during development.

End to End testing ensures that the application is working exactly the way it is expected to. For the effective user experience and increasing reliability of the application, the communication should be efficient between the interfaces and the endpoints.

The Login screen of the software is an example of it in which the user is required to interact with the UI by providing the username and password and clicking the Submit button.

This submits button activates an event to match the information available in the database outside the software native environment. The Login is allowed or denied based on information provided.

A user can also add data to the same database by using signing in option. The software has to deal with multiple system pass through many interfaces so it is necessary to assure that it is pointing at the right location in a certain amount of time.

The quality of the User experience doesn’t depend only on the correct functioning of the software but also on the time it takes to perform a user’s instruction.

End to end testing plan helps in evaluating all these valuable details.

Benefits of E2E Testing

1. It ensures that everything is functioning not just individually but all together. Sometimes it is also referred to as system health check or Integration test depending upon the scale of testing.

But sometimes people consider only backend, API, database layer or frontend layer testing as an end to end testing but it is much more than that.

end to end testing
Image Source: Testbytes

2. It also expands the test coverage as it is trying to cover all the possible software working scenarios. Generally, when any unit testing or functional testing is done, the focus is not on the user’s way of operating it.

So end to end testing makes the testers write a test to operate the software in all possible environment a user will be. Because a feature might be working in one environment and not in another environment so the development team should try to cover as many environments as possible.

It will help in developing a software that can serve customers globally, using the software on different kind of devices, web browsers, operating systems and network conditions.

3. End to end testing also increases the chances of detecting the bugs before the user will. It is considered impossible to detect all the defects in the software during development because testing involves test cases less than the ways the users will be using the software.

But bugs detection during development is always preferred over deploying a less reliable product in the market and this testing methodology help in doing that.

4. The resources required to fix a defect is not just money but also the time and efforts the developers have to spend are counted and E2E testing reduces the resources required to make corrections.

End to end testing is performed once all the system and unit testing are performed over the software under test.

Types of E2E Testing

This testing can be done both automatically and manually depending upon the software features and testing needs.

end to end testing
Image Source: ProAndroidDev

1. Manual

It is difficult to write tests for the software that involves dependency on other applications for its functioning as it has more complex interfaces to write in form of test cases.

In such cases, automating tests become difficult and manual testing is preferred. A tester can test the whole process from beginning to end.

2. Automated Testing

Selenium and Protractor are two of the most popular tools for automated end to end testing. Even Cypress is also recommended for this purpose.

A successful end to end testing depend upon the tester’s knowledge of the whole system and it’s subsystem as it will assure the development team that the product is good enough for offering quality user experience.