Many modern applications use a service-oriented architecture, connecting various subsystems that may be external to the application. If one subsystem fails, it can result in a complete application failure. End-to-end testing helps ensure all components are functioning properly by testing the entire application flow from start to finish. One can perform end-to-end testing using two ways: manual testing and automation testing.
End-to-end testing is an intriguing approach that is frequently used in agile and other testing methods, yet it can be challenging to grasp. It is similar to unit and functional testing but covers more than individual units. In the following sections, we will delve into end-to-end testing, a software testing technique that evaluates an application’s workflow in real-life user scenarios.
In agile development, end-to-end testing plays a key role by evaluating the software through a simulated user experience, enhancing the final product’s value. This testing serves two main purposes:
- To test the major business components of the application such as communication with other systems, interfaces, databases, networks, and applications
- To create a production-like scenario and test the happy flow, allowing for a simulation of real-time conditions and environment to prevent application crashes.
Nonetheless, end-to-end testing is an extensive procedure.
What is End-to-End Testing?
E2E testing is a technique used during the SDLC to validate the overall functionality and performance of a web-based application in production-like conditions. It simulates real-world user scenarios from start to finish to ensure the system operates without any issues. This type of testing checks that all external dependencies and components work together seamlessly. Complex modern software systems often have multiple interconnected subsystems, making E2E testing crucial in identifying and fixing issues before deploying to production to avoid potential failure of the entire application.
E2E testing is typically performed toward the end of the software development lifecycle, before releasing the code to production. It’s a comprehensive review of the interconnected system and is repeated if any issues are found during testing. If a defect is discovered, the development team will need to log it, analyze the data, and pinpoint the source of the bug. Once the source is identified, it can be fixed and retested to ensure the system works as expected.
What is Agile?
Agile is a methodology for software development that emphasizes collaboration, flexibility, and customer satisfaction. It follows an iterative and incremental approach to deliver a product incrementally and adapt to changing requirements. Agile promotes teamwork and regular communication between team members, stakeholders, and customers. It values working software over comprehensive documentation and encourages continuous improvement through regular retrospectives.
Why End-to-End Testing is Critical in Agile?
Dev and test teams in agile development focus on one service per sprint out of all the integrated services in an application. The objective of E2E testing in agile is to ensure the stability and quality of the product before its release and increase confidence in its functional flow. It is usually performed in every iteration or sprint and helps reduce the risk of major bugs and repetitive testing efforts.
The end-to-end testing process checks the functionality of the application from the front-end to the back-end, including interfaces and endpoints. Following are few of the reasons as to why it is required:
- Backend Health: End-to-end testing evaluates the database and backend layer of the application, ensuring that the core functions are performed accurately.
- Distributed Environment Errors: It enables testing of applications built on SOA or cloud environments and helps identify problems in the core for applications with multiple components.
- Multi-tier System Behavior Validation: End-to-end testing checks the overall functioning and behavior of applications with complex architecture or workflows divided into multiple tiers. It also assesses the application’s behavior in connected systems.
- Interaction Accuracy: The front-end testing aspect of end-to-end testing ensures that the application behaves consistently and provides a consistent user experience across different platforms, devices, and environments.
- Test Case Reusability: During various stages of the application’s lifecycle, end-to-end testing provides the option to execute repeatable test cases, increasing test coverage and ensuring the owner’s confidence in the application’s performance.
However, there’s a risk that some subsystems or services may go unnoticed and cause problems. Therefore, the QA team must ensure that changes to one service don’t negatively impact the entire workflow.
E2E Testing Methods:
- Horizontal E2E Testing: This method tests each phase of the business workflow to ensure that the developed application aligns with the functional requirement document. It verifies each workflow through individual applications from start to finish and is typically performed at the end of the release cycle in a stable environment. This approach provides more coverage on the functional aspect but can only be done after all release changes are implemented.
- Vertical E2E Testing: This method involves testing in layers, with tests performed in sequential and hierarchical order. It tests each component separately and thoroughly and is more integrated into the SDLC. Common approaches include BDD, TDD, and CI-CD. The best way to achieve this is by performing unit tests for each component and then testing the network infrastructure, API integration, and UI layers. This method provides high coverage of testing for the core code and allows for easy identification of defects in each stage.
The Importance of Metrics in End-to-end Testing
Gathering metrics during end-to-end testing helps to quickly identify and isolate any issues that arise, making it easier to fix them. After unit tests have been created to confirm the fix, the code can be tested end-to-end again.
End-to-end testing also measures deviations from expected results under different conditions, providing valuable data. Key metrics to consider include:
- The status of test preparation
- A weekly summary of test progress
- A detailed report of any bugs found
- Monitoring of the testing environment.
Steps of End-to-End Testing
- Study the requirements and understand app functionality
- Establish a test environment based on requirements
- Evaluate software and hardware needs
- Define expected system responses
- Determine necessary testing methods and protocols
- Plan test cases
- Execute tests, document and preserve results.
Making E2E testing in Agile more efficient…
- Automating test cases with high coverage
- Keeping E2E automation separate from other tests
- Running E2E tests before each sprint release
- Integrating E2E tests with CI/CD pipeline using tools like Jenkins
- Scheduling Jenkins job to run at night for faster analysis of failed tests
- Taking advantage of Selenium Grid with Docker for cross-browser and parallel testing
- Using Docker containers to simulate the production environment and avoid environment-related issues
Advantages of End-to-End Testing
- Improves Overall Product Stability and Quality
E2E testing tests various layers, including data, business, integration, and presentation, resulting in a more stable and high-quality product.
- Boosts Confidence in Business Workflow
E2E testing validates the functional flow and performance across all endpoints and devices, which increases confidence in the application before release.
- Reduces Risks with Regular Testing
Testing the application in every iteration and sprint reduces the chance of major bugs.
- Saves Time and Resources
E2E testing reduces repetitive testing efforts and the cost of fixing errors at later stages of product development. Automating E2E testing allows for quick adaptation to changing business requirements and improves the testing project’s agility.
3 Activities in E2E Testing:
User Functionality Testing
- Identify the features and subsystems of the software
- Record actions, inputs, and outputs for each function
- Determine relationships between user functions
- Evaluate if functions are independent or reusable
Condition Testing
- Determine the set of conditions for each user function, including timing, data, etc.
Test Case Development
- Create test cases for each functionality of user functions
- Assign a separate test case for each condition.
Challenges in End-to-End Testing
- Workflow Complexity: E2E testing requires running test cases in a specific sequence to match the user’s navigation through the application. This can be challenging, especially with complex workflows and the need to create and run many tests.
- Test Environment Access: Testing apps in dev environments is straightforward, but testing in client or production environments can be difficult. These environments are not always available for testing and accessing them may require installing local agents and logging into virtual machines. Ensuring an ideal test environment can be challenging, especially when dealing with system updates and other interruptions.
- Real-Device Testing: E2E testing requires testing on real devices, which can be difficult to access. The best solution to this challenge is testing on a real device cloud.
By utilizing the LambdaTest cross browser testing platform, developers and testers can perform end-to-end testing of their websites and mobile apps on over 3000+ browsers and operating systems. It provides a variety of features that are critical for developers to increase their end-to-end testing efforts, including monitoring dashboards to identify unstable tests and the ability to run tests in parallel. You can also achieve high performance and test execution speed with LambdaTest’s HyperExecute end-to-end test orchestration cloud.
Conclusion
End-to-end testing is crucial in today’s agile world as applications are interconnected with multiple systems that are not part of the application environment. The aim of end-to-end testing is to validate the integration of the system and its functional flow. In testing an application, it’s crucial to consider not just the user interface but also the data, processes, and logic behind the application’s behavior.
To ensure the overall quality of the application, it’s important to verify both the frontend and backend, functional flow, and integration of connected systems.