Learn how to implement continuous testing in DevOps, including key components, the differences between traditional and continuous testing, and how continuous integration, continuous delivery, and continuous testing interact.
Continuous testing is the practice of automatically running frequent unit, integration, and regression tests throughout the software development life cycle (SDLC) to identify and fix defects as early as possible. It is different from regular testing in that it is an ongoing process rather than a one-time event, and it is sufficiently automated to allow for on-demand execution.
In this article, we will explain the importance of continuous testing in DevOps and how it helps teams ensure the quality and reliability of software.
Traditional software testing is the approach to testing where quality assurance is conducted at predetermined intervals during the development process, typically at the end of each iteration or release. It may include manual or automated testing tools.
Continuous testing is an approach that involves ongoing testing throughout the development process. It means that testing is conducted as code is written and changes are made, providing faster feedback on code quality. This approach includes a broader range of testing types—such as unit, functional, performance, security, and integration testing—to ensure that all aspects of the product are thoroughly tested.
The key differences between traditional and continuous software testing are the speed, frequency, and level of manual effort involved in testing. Continuous testing improves the overall quality of the product by identifying and fixing issues soon after developers have written the code, which is when the context is freshest in their minds.
A continuous testing framework is a system that enables organizations to test their software continuously throughout the development process. It consists of several components that work together to ensure that the software is tested thoroughly and efficiently.
As illustrated in the diagram above, we can divide the continuous integration process into five steps:
Each of these components plays an important role in ensuring that the codebase is of high quality and that any changes made do not introduce new bugs. By incorporating these components into the development process, engineers can ensure that their code is thoroughly tested and ready for release to production.
Continuous integration and continuous delivery are two important concepts in DevOps that are used to improve the speed and quality of software delivery. Here, we will explain the difference between these two concepts and how continuous testing fits into the overall process.
CI is a best practice involving integrating multiple developers' code changes into a central repository using version control tools. This integration process is automated with continuous integration tools that help identify and resolve integration problems early in the development cycle, store and organize code dependencies, and automatically compile the code in preparation for execution.
Continuous delivery (CD) automates the deployment of code changes to test and production environments using infrastructure-as-code tools. Containerized applications are easier to deploy using solutions like Docker Compose, which can deploy multiple containers simultaneously with a single command.
Continuous testing is a fundamental part of the continuous delivery (CD) process, which is why it’s not separately called out and the popular CI/CD acronym doesn’t include CT.
Continuous testing includes unit testing of individual code components and integrated testing of the complete application. Importantly, it also encompasses regression testing to ensure that changes in the current release haven’t adversely affected the functionality of the features in the previous release of the software.
CT also includes tests intended to evaluate the application’s security vulnerabilities. Test coverage is expressed as a percentage of the total code base tested, so 100% would mean testing the entire code base. This is an essential CT measurement because it highlights the risk of defects and security flaws going unnoticed in the uncovered parts of the application; the higher the percentage, the better.
Once the code checked in by the developers is integrated along with its dependencies and compiled (CI), the application is deployed to a test environment (CD) and tested using automated scripts (CT) before it’s finally deployed to production (CD).
Here is a high-level summary of the steps involved in continuous testing in DevOps:
Test environments are necessary for enabling continuous testing in the DevOps pipeline. They provide a controlled and consistent environment for running tests, ensuring that the software functions as expected before it is deployed to production.
A persistent test environment refers to a dedicated environment that is set up once, updated over time, and used repeatedly to test the software. It is usually used for regression testing to ensure that the software continues to function as expected after new code changes are made. A persistent environment doesn’t allow multiple streams of testing to happen simultaneously since the common resources are shared among all developers and testers. Another downside is the lack of isolation, which means that when a developer introduces a new bug that blocks the code from being compiled, it must be addressed before others can proceed with their testing.
An ephemeral test environment, also known as a preview environment, is a temporary test environment created for each feature branch. This approach allows for isolated testing of each new feature before it is integrated into the main branch, resulting in more efficient testing and faster feedback for developers.
Implementing and maintaining ephemeral platforms traditionally required a significant investment and was available only to large organizations with lots of time and deep pockets. Modern tools like Uffizzi streamline the process of deploying ephemeral environments for each feature branch, allowing for isolated testing of each new feature before it is integrated into the main code branch. If the tests pass, the code is automatically deployed to the production environment; if the tests fail, you can roll back the code and notify the developers of the failure.
Tools like Uffizzi can take advantage of the Docker Compose file to set up an entire application environment for the duration of the testing, including the database and backend services, tearing the environment down once the testing is completed.
By integrating testing into the CI/CD pipeline, continuous testing in DevOps allows for faster detection and resolution of defects, resulting in a higher-quality software product.
The following best practices will enable you to get the most from continuous testing:
Continuous testing is a crucial practice in DevOps that helps teams ensure the quality and reliability of software. By frequently and automatically running tests throughout the development life cycle, teams can quickly identify and fix problems, improve the speed and efficiency of the development process, and deliver high-quality software to users.
Continuous testing is different from regular testing, which is a one-time event that typically occurs at predetermined intervals during the development process. To implement continuous testing in DevOps, it's important to consider tools and processes such as test automation, continuous integration and delivery, collaboration and communication tools, and testing environments.
Uffizzi automates setting up and tearing down a test environment for each feature branch, dramatically improving developer productivity by maintaining isolated and ephemeral full-stack test environments integrated with a CI/CD pipeline. Uffizzi is available both in an open-source project and as an environment-as-a-service (EaaS) offering.