Modern development environments, in which rapid continuous delivery is facilitated by automated continuous integration/continuous development (CI/CD) pipelines, require thorough and automated testing in development prior to integration. This article explains how test-driven development (TDD) and acceptance test-driven development (ATDD) methodologies reduce CI/CD lead times.

Lack of test automation in development impacts CI/CD lead time for subsequent integration, delivery and deployment stages of a CI/CD pipeline in the following ways:

• Increased defect rate: Without automated testing during the development stage, more defects and issues are likely to be introduced into the codebase, increasing the time spent on debugging and fixing issues in later stages.
• Slower feedback loop: Without test automation, the feedback loop between code changes and test results is slower, making it more challenging to identify and resolve issues quickly. This delay can impact the overall lead time in the CI/CD pipeline.
• Reduced confidence in releases: When testing is not performed adequately or isn’t automated, there is less confidence in the quality of the software being released. This may lead to more manual testing and validation, further increasing lead times.
• Inefficient use of resources: Without test automation, developers and testers need to spend more time on manual testing, reducing the time available for developing new features or fixing existing issues.
• Increased merge conflicts: When test automation is not performed early in the development stage, the risk of merge conflicts increases as different developers work on the same codebase. Resolving merge conflicts can be time-consuming and may cause delays in the integration, delivery, and deployment stages.
• Decreased stability and reliability: Inadequate test automation during the development stage can lead to less stable and reliable software. This may require additional time and effort to address issues and ensure that the software is production-ready.
• Inconsistent test environments: Manual testing may not always be conducted in a consistent environment, leading to potential discrepancies between development, staging, and production environments. This can cause unexpected issues and delays in the pipeline.
• Hindered collaboration: Lack of test automation may reduce visibility into the quality of the codebase, making it more difficult for team members from development, QA, security and operations to collaborate effectively and identify issues early.

Although CI/CD pipelines help catch issues and ensure code quality through automated builds and tests, having a strong foundation of test automation during the development stage helps minimize the potential for issues in the pipeline and ensures a smoother CI/CD process.

There are several reasons why many development teams do not automate tests prior to integration, despite the benefits of doing so.

• Lack of awareness or understanding: Some development teams may not be aware of the benefits of test automation or may not fully understand how to implement it effectively in their development process.
• Insufficient skills or experience: Test automation often requires specialized skills and knowledge, and some development teams may lack the necessary expertise to implement it effectively.
• Time constraints: Developing and maintaining automated tests can be time-consuming. Teams working under tight deadlines might prioritize feature development over creating automated tests, believing that it will save time in the short term.
• Limited resources: Test automation tools and infrastructure can require significant investments in terms of cost and resources. Some organizations may not have the necessary budget or resources to invest in test automation, especially for smaller projects or teams.
• Resistance to change: Some teams may be resistant to adopting new practices, particularly if they have been successful with their existing processes. Changing established workflows and learning new tools can be challenging and may encounter resistance from team members.
• Incomplete or rapidly changing requirements: In situations where requirements are unclear or frequently changing, development teams may struggle to create meaningful automated tests, as they may require continuous updates to stay relevant.
• Overemphasis on manual testing: Some teams may place a greater emphasis on manual testing due to a belief that it provides more accurate or thorough results. This perception can lead to a reluctance to invest time and effort into developing automated tests.
• Fear of increased maintenance: Automated tests, like any other code, need maintenance and updates as the application evolves. Some teams may be concerned about the additional effort required to maintain a test suite, particularly if they have limited resources.

The amount of test automation that should be done in development prior to the integration stage of a CI/CD pipeline depends on several factors, including the complexity of the application, team resources and the specific project requirements. However, here are some general guidelines to help you determine the right balance:

• Unit tests: Developers should aim to automate most, if not all, unit tests during the development stage. They are typically fast to execute and provide quick feedback, allowing developers to catch issues early and minimize the number of defects that make it to the integration stage.
• Component and integration tests: While unit tests focus on individual components, component and integration tests verify the interaction between different components or services. These tests should be automated as much as possible to ensure that any issues arising from component interactions are identified and resolved quickly.
• Static code analysis: Automating static code analysis checks during development helps identify code quality issues, security vulnerabilities, and potential performance bottlenecks early in the process.
• Code coverage: Strive for a high level of code coverage with your automated tests. However, it’s important to remember that code coverage is just one indicator of test quality and should be complemented by other testing strategies.

Striking the right balance between automated and manual testing is important. Automate tests that are repetitive, time-consuming or prone to human error. Manual testing should be reserved for exploratory testing, usability testing and other areas where human intuition and judgment are necessary.

Test-driven development (TDD) and acceptance test-driven development (ATDD) are development methodologies that emphasize creating automated tests before writing the actual code, helping teams ensure code quality and catch issues early prior to integration.

Test-driven development (TDD) is a software development methodology that emphasizes writing tests before writing the actual code. The primary goal of TDD is to create clean, maintainable and bug-free code by catching issues early in the development process. TDD follows a short iterative cycle consisting of three main steps: Write a test, make the test pass and refactor the code. The developer starts by writing a test for a specific feature or function, which initially fails. Next, the developer writes the minimal amount of code necessary to make the test pass. Finally, the developer refactors the code to improve its structure and readability while ensuring that all tests still pass.

Acceptance test-driven development (ATDD) is an extension of TDD that focuses on defining and validating the high-level requirements and acceptance criteria for a feature or functionality before development begins. ATDD involves collaboration among developers, testers, and business stakeholders to ensure that the application meets the needs of its users. The process begins with writing acceptance tests, which are derived from the user’s perspective and based on the acceptance criteria. These tests are written in a human-readable language to facilitate clear communication among all team members.

Once the acceptance tests are defined, the development team follows the TDD process to implement the feature, using the acceptance tests as a guide. As the team develops the code, they also create unit tests and other lower-level tests to validate the implementation. The acceptance tests are executed as part of the development process and serve as a measure of progress. When all acceptance tests pass, it indicates that the feature or functionality meets the defined acceptance criteria, and the development task is considered complete. By using ATDD, teams can improve collaboration, ensure that the application meets user expectations and reduce the risk of miscommunication or misunderstanding requirements.

Hurdles to overcome when transitioning to TDD and ATDD include:

• Mindset shift: Adopting TDD and ATDD requires a change in mindset, where testing is considered an integral part of the development process rather than an afterthought.
• Skill development: TDD and ATDD require specialized skills in writing effective tests and implementing test automation. Development teams may need to invest time and resources in acquiring these skills.
• Time and resource allocation: Transitioning to TDD and ATDD might initially lead to a perceived increase in development time, as writing tests before code can seem slower. However, the long-term benefits of improved code quality and reduced debugging time should be considered.
• Collaboration and communication: ATDD relies on effective collaboration and communication among developers, testers, security, operations and business stakeholders. Establishing a culture of open communication and collaboration is crucial.
• Tooling and infrastructure: Implementing TDD and ATDD may require investments in new tools or changes to the existing development infrastructure to support test automation and continuous integration.

In the context of TDD and ATDD, the roles of quality assurance (QA), security and operations teams are crucial for ensuring a well-rounded and robust software development process. Their involvement helps to address various aspects of the application, leading to a more reliable and secure product.

• Quality Assurance (QA): QA team members collaborate closely with developers in both TDD and ATDD methodologies. They can help define test cases, create test plans and provide input on acceptance criteria. In ATDD, they play a particularly significant role in developing and validating acceptance tests, ensuring that the application meets the defined requirements and user expectations. QA team members may also be involved in setting up and maintaining test automation infrastructure, analyzing test results and identifying areas for improvement.
• Security: Security professionals contribute to TDD and ATDD by identifying potential security vulnerabilities and ensuring that the application is developed with security best practices in mind. They can help define security-related test cases and help to embed security into the application, reducing the risk of vulnerabilities and improving the overall security posture.
• Operations: Operations teams are responsible for managing the infrastructure and deployment processes that support the application. In TDD and ATDD, they can collaborate with developers to ensure that the application is designed and developed with operational concerns in mind, such as scalability, performance and maintainability. Their involvement also helps to promote a DevOps culture where development and operations teams work together to ensure the application’s success in production environments.

A practical roadmap for teams to transition to TDD and ATDD while overcoming the hurdles mentioned earlier could look like this:

Build awareness and buy-in:

Start by educating the team on the benefits and principles of TDD and ATDD. Obtain buy-in from team members and stakeholders to ensure a smooth transition.

Provide training and skill development:

Organize workshops, training sessions or pair programming exercises to help team members develop the necessary skills for writing effective tests and implementing test automation.

Start small and iterate:

Begin the transition by applying TDD and ATDD practices to small, manageable parts of the project or a pilot project.

Foster a culture of collaboration:

Establish regular meetings or workshops for developers, testers, security, operations and business stakeholders to collaborate on defining requirements and acceptance criteria. Encourage open communication and shared responsibility for test creation and maintenance.

Set up the necessary tooling and infrastructure:

Allocate time and resources to select, set up and configure these tools and ensure they are properly integrated into the development process.

Monitor progress with metrics:

Monitor key metrics, such as code coverage, test execution time, defect rates and lead time to track progress and identify areas for improvement.

Continuously improve and adapt:

Regularly review the team’s progress, gather feedback, and adjust the process as needed.

Summary

TDD and ATDD methodologies contribute to reducing CI/CD lead times by automating tests during development. This improves code quality, minimizes defects and promotes collaboration among team members from the outset of the development process. By writing tests before the actual code and focusing on meeting acceptance criteria, teams can catch and resolve issues early, leading to fewer delays and reduced time spent on debugging and fixing errors during the integration, delivery and deployment stages. These practices also help ensure that the application aligns with user expectations and operational requirements, resulting in a smoother and more efficient CI/CD pipeline.

Anyone who is passionate about modern quality engineering processes for building high-quality software to participate is encouraged to join new ShiftSync Community from Tricentis to engage in discussions about this topic and other development methodologies.