Guide to End-to-End Testing and Best Practices

We compiled an ultimate guide to end-to-end testing which will help you discover numerous tips on testing and improve your skills.

Guide to End-to-End Testing and Best Practices

Today, we’ve prepared for you a comprehensive guide, where the DogQ specialists will explore the ins and outs of end-to-end testing, provide you with practical examples, and give you useful professional advice that will revolutionize your approach to testing.

Table of contents

Whether you are a seasoned professional or just starting out, this guide is designed to equip you with numerous tips and techniques to ensure your testing strategy is flawless. From understanding the importance of end-to-end testing to mastering different testing methodologies and best practices, we have got you covered. Get ready to elevate your testing game and unlock a whole new level of expertise.

Let's start!

What is End-to-End Testing?

End-to-end testing (or e2e) is a method used in software testing where the entire system is checked to make sure everything works together properly. Imagine you’re building a sandwich: end-to-end testing would be like checking if the whole sandwich tastes good, not just each ingredient separately.

End-to-end testing is used after all the individual parts of a system have been tested on their own, to make sure that all the parts work together and there’s no problem when they interact. It’s usually done near the end of the development process before the software is given to the users. It helps find any issues that might come up when the whole system is in use, so they can be fixed before the users encounter them.

End-to-End Testing Best Practices

Now, when we already know the basics, it’s time to learn best practices, as with any other testing methods, e2e testing also has its best practices to follow:

1. Plan and document the testing process

Clearly define the scope, timelines, and expected output. The documentation should include a detailed understanding of the system, the end-to-end processes to be tested, and the expected outcomes.

2. Test early and often

Starting the testing process as early as possible in the software development life cycle can help catch and correct errors sooner, reducing costs and time to market.

3. Use realistic scenarios

End-to-end testing should represent real user scenarios, covering all the possible user interactions with the application.

4. Automate when possible

Though not all tests can be automated, automation can significantly speed up the testing process and reduce human error.

5. Continuously review and update tests

As the software evolves, test cases should be regularly reviewed and updated to ensure they're still relevant.

6. Include API Testing

This involves testing the application programming interfaces (APIs) directly and as part of integration testing to determine if they meet functionality, reliability, performance, and security expectations. For instance, a tester could automate API end-to-end testing testing to verify that when data is sent to an endpoint, it returns the correct status code and response body.

7. Monitor Errors

This includes continuously monitoring the application for errors during its operation, providing the ability to identify and fix issues in real time.

8. Avoid Exception Testing

This type of testing seeks to identify how an application behaves when confronted with unexpected input or unexpected user behavior. But the purpose of e2e testing is to test the common user scenarios in relation to the software, rather than carry out exception testing. If exception testing is necessary, integration testing or low-level unit testing are better choices.

9. Leverage Automation Testing

Automation can significantly speed up the testing process and increase its accuracy by reducing human error. Automated end-to-end tests can be run at any time, providing continuous feedback on the application’s health.

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Selecting the right testing tools can be crucial to the success of your end-to-end testing. It should be based on the needs of the project, expertise of the team, cost, and community support. 

Top 3 Benefits

As follows from the definition, e2e testing allows to check whether all the system element works properly with each other. But this is not the only benefit of using e2e tests, here are 3 more:

Streamlined regression testing workload

By conducting successful end-to-end tests, subsequent tests following user flow are automatically triggered during changes, enabling regression testing to concentrate on impacted components.

Improving user experience

By simulating real user scenarios, end-to-end testing can help identify any possible issues that might disrupt the user experience. For example, an eCommerce application might work well in general, but if the transition from the user cart to the payment gateway is not smooth, users may abandon their carts. Testing can catch and help fix this issue before deployment.

Saving time and resources in the long run

While end-to-end testing might seem time-consuming, it can save resources later by catching problems before the system goes live. It’s cheaper to fix issues during the development phase rather than after deployment. For example, discovering a bug causing data loss in a cloud storage service during testing would prevent potential losses and a hit on the company’s reputation if found by users after deployment.

Why Is E2E Testing Important for Your Testing Strategy?

Well, now we know what is end-to-end testing, and what are the benefits of this testing type, but what can happen if skip it? Well, it’s better not to do so, and here’s why: it plays a critical role in a comprehensive testing strategy, checking the overall flow of the system, from start to finish, and simulating real-world user scenarios. It helps verify that all components of the system, including databases, networking, and other services, are communicating as expected, with no bugs on the client side.

An illustration of the testing pyramid

Now, let's relate this to the testing pyramid, a concept that visualizes different layers of testing, from granular to holistic:

  1. At the base, we have unit tests, which check individual components of your system. They’re like examining each brick in a wall separately;
  2. In the middle, there are integration tests that verify that groups of components, or “units”, can work together – this is like ensuring each layer of bricks holds together;
  3. End-to-end testing sits at the top of the pyramid. It’s like inspecting the whole wall for stability. It’s fewer in number due to their complexity and time-consuming nature but of great value because they simulate actual user behaviors and system interactions.

While unit and integration tests are excellent for catching specific, localized issues early, end-to-end tests ensure the entire system functions as expected when all the different pieces are working together.

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However, it’s important to maintain a balance as per the pyramid strategy – a broad base of unit tests, fewer integration tests, and the minimal but critical end-to-end tests.

3 Types of Tests

As you may already guess, there can be several end-to-end (e2e) testing methods depending on your product type and the chosen testing strategy. Let’s dive into them all one by one:

Manual horizontal e2e testing

This is a testing method where a tester mimics the actions of a user, testing the system from one end to the other. For example, in an online shopping platform, a tester would manually go through the entire process a user would – searching for a product, adding it to the cart, checking out, and making the payment.

Manual vertical e2e testing

This is similar to horizontal testing but goes a layer deeper, testing the backend processes as well. Using the same shopping example, vertical testing would also cover checking if the order details are correctly stored in the database, whether the inventory gets updated, etc.

Automated e2e testing

Here, instead of a person, the software does the testing. Automation can be applied to both horizontal and vertical testing. It’s typically used for repetitive tasks or complex scenarios that are hard for humans to execute accurately every time. For example, a script could be written to simulate thousands of users simultaneously making a purchase on an e-commerce site, a scenario that would be difficult and time-consuming to test manually.

Advantages of Using Test Automation

Let’s concentrate now on end-to-end testing automation, as it provides numerous benefits, and using no-code automated testing platform platforms like dogq.io can enhance those benefits even further, providing each QA engineer with:

Efficiency and speed

Automated tests run much faster than manual tests and can be run at any time, even outside of work hours. This increases the testing efficiency significantly. For example, with dogq.io, you can schedule your tests to run automatically during off-peak hours, ensuring your software is continuously tested without any manual intervention.

Simplified test design process

End-to-end testing requires collaboration among multiple team members and stakeholders, and end-to-end testing automation allows for flexibility and seamless collaboration between individuals with different coding expertise. Developers can create custom keywords, while QA teams can easily create tests through a drag-and-drop interface.

Versatile testing capabilities

The software for automated testing can test applications on various operating systems, multiple browsers and device types, ensuring compatibility across different environments in a few clicks.

Consistency

Automated e2e tests perform the same actions in the same order every time they run, reducing the risk of human error. This provides consistency, which is particularly important in end-to-end testing where the same steps need to be executed multiple times.

Scalability and reusability

Automation makes it easy to replicate tests across different devices, browsers, or environments, which would be tedious and time-consuming to do manually.

Extensive integration options

Integrating with popular CI/CD and DevOps tools such as Jira, Jenkins, or Docker facilitates smoother collaboration and a more streamlined testing workflow.

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Most popular frameworks have a large community of users and regular updates, so you’ll have access to help and new features.

Overall, automating end-to-end tests, especially with the help of no-code platforms like dogq.io and structured testing frameworks, can significantly enhance the efficiency, reliability, and coverage of your testing process.

End-to-End Testing Lifecycle Explained

Now let’s dive into the process of e2e testing as it is, and study all its stages one by one:

End-to-end testing lifecycle

Test Planning

The initial stage, here the team outlines the strategy that will guide the entire testing process:

  • identify the required resources;
  • establish schedules and deadlines;
  • determine testing tools and environment;
  • define the scope and objectives of the testing;
  • identify the types and levels of testing to be performed.

Test Design

In this phase, the test team designs the tests that they will execute on the software:

  • identify specific conditions or scenarios that the software will face;
  • design tests that can validate the software’s behavior under those conditions;
  • create test cases and test data based on the identified scenarios, all derived from the requirements and specifications of the software.

Test Execution

This is where the actual testing happens. The team runs the tests that they designed in the previous stage on the software. They may perform this manually or use automated tools depending on the plan they made in the Test Planning stage. If a test case fails, it’s documented and sent back to the development team for correction.

Results Analysis

After executing the e2e tests, the team gathers and examines the test results to find any defects or issues:

  • measure the software’s quality and functionality based on these results;
  • report the bugs found during testing to the developers for fixing;
  • validate the fixes once they are implemented.

Test Closure

The final stage in the testing process is Test Closure. Here, the team compiles a final report of all testing activities, results, bug reports, and their resolutions. It serves as a record for future reference and helps to improve the testing process for the next software development cycle.

As you can see, end-to-end testing involves assessing the software from every angle, considering all the interactions between different system components, including databases, networks, and interfaces. It ensures that the software system behaves as expected in real-world scenarios, providing confidence to stakeholders that the system is ready for deployment.

Thus, e2e testing is a software testing methodology that validates the entire software product from start to finish, ensuring that it behaves as expected and that all integrated components function properly. It verifies the system flow under real-world scenarios, including interaction with the database, network, hardware, and other applications. It’s better to use automated e2e testing, as it can greatly reduce the time spent on testing and improve your testing coverage.

In order to run the tests smoothly, you should follow the e2e testing lifecycle and best practices, described here above in the text. Always improve your skills by practice, and don’t be afraid to turn to a testing community for help. Wish you 100% e2e testing coverage and stay updated for more guides like this!

Also, if you need professional testing help to test your product, or have any testing-related questions, don’t hesitate to ask – the DogQ team is here to help you out!

What does E2E testing include?

End-to-end (e2e) testing involves validating the entire system flow from start to finish under real-world scenarios. This type of testing includes testing of all integrated components of the system, inter-system communications, and interaction with the database, network, etc.

Is API testing end-to-end testing?

API testing isn’t specifically end-to-end testing, but it can be part of it. While API testing focuses on determining if software systems communicate correctly through API calls, e2e testing validates the entire application flow, including but not limited to API interactions.

What is end-to-end testing with example?

End-to-end testing refers to a testing method that validates the complete system flow from beginning to end. For example, in a mobile eCommerce website, mobile end-to-end testing might involve creating a new user, logging in as that user, searching for a product, adding the product to the cart, checking out, and finally verifying the purchase in the user’s order history.


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