21 December 2023
07 Min. Read
Shift Left Testing: Types, Benefits and Challenges
Fast Facts
Get a quick overview of this blog
Get to know about shift-left testing approach
Learn about the differences in shift-left testing and the traditional methods of testing
See how shift-left testing is a boon for agile architectures like microservices
Learn about the HyperTest way to implement shift-left testing
Have you ever been involved in managing a software project that exceeded its budget or faced time constraints? It's a common experience. Despite common misconceptions, inadequate planning isn't the sole culprit when a project surpasses its deadline. The real challenge lies in the code validation process of the project.
In essence, the pivotal factor is software testing. Specifically, insufficient and delayed software testing tends to be the root cause. One proposed solution to address this issue is to implement shift-left testing.
What is Shift-Left Testing?
Shift Left testing is an approach that involves moving the tasks related to testing earlier in the development process. This means that testing tasks that are traditionally done at a later stage of the operations should instead be performed at earlier stages–particularly those related to API testing.
This concept is rooted in the idea that finding and fixing defects early in the development cycle is less costly and time-consuming than doing so later.
The Focus of Shift-Left Testing:
These are smaller, more atomic tests assessing the output of the System Under Test (SUT) using defined inputs.
Offers rapid and highly precise feedback to developers regarding breaking changes. This allows developers to quickly debug, fix, and release patches.
Typically, unit or integration tests are employed, excluding End-to-End (E2E) tests.
These tests should address both functional and logical issues.
Where the Shift-Right/ Traditional Testing Lacks?
Conventional models position testing near the deployment phase, causing a bottleneck in the release process. This bottleneck arises from the accumulation of numerous changes, impeding efficient testing and subsequently delaying releases.
Principles of shift-left empower testing teams to enhance developer oversight in the release process. This is achieved by facilitating developers to test their changes as soon as they are merge-ready, bypassing the need for QA team involvement.
The shift-left testing process operates concurrently with the development process, granting developers the capability to implement minor changes to the application. These changes can be promptly tested and readied for immediate release.
Shift-Left vs. Shift-Right Testing
Aspect | Shift-Left Testing | Shift-Right Testing |
Timing | Early in the SDLC | Later stages, including post-release |
Focus | Prevention of defects | Detection and resolution of issues in real-world use |
Methods | Unit, integration, and early system testing | Performance, usability, and A/B testing |
Involvement | Primarily developers and testers | Involves operations and end-users |
Feedback Loop | Immediate and frequent feedback during development | Feedback after deployment or in late stages |
Cost of Defect Resolution | Lower, as issues are simpler to fix early in the cycle | Higher, as issues may require more complex fixes |
Goal | Enhance quality and collaboration, reduce time to market | Ensure reliability, usability in real-world scenarios |
Why Shift-Left Testing is Needed?
It is an essential methodology because it emphasizes the integration of testing early and often in the SDLC. The key reason for its necessity lies in its ability to identify and address defects earlier, which significantly reduces the cost and time required for fixing issues later in the development process.
In traditional models, testing is often conducted after the completion of the development phase, leading to the discovery of bugs and errors late in the cycle. This not only increases the complexity of resolving these issues but also escalates the costs involved.
By shifting testing to the left, i.e., closer to the start of the project, teams can ensure that code is tested as it is written. This approach not only enhances the overall quality of the software but also aligns with agile and continuous delivery practices, promoting faster release cycles and better collaboration between developers and testers.
This translates into more efficient resource utilization, improved product quality, and a higher return on investment, making shift-left testing a strategic priority in modern software development.
Benefits of Shift-Left Testing
For development teams, the shift towards earlier testing in the process presents a host of advantages. These benefits can be encapsulated in two distinct outcomes: accelerated innovation and a shortened time to market for new features.
Here are several more advantages:
Automation: Shifting testing to the left enhances the effectiveness of automation. This yields several key advantages, including a significant reduction in human errors, more comprehensive test coverage through concurrent testing, the ability for testers to focus on higher-priority activities, and a decrease in production issues.
Faster Innovation: Early API testing facilitates the enhancement of code sanity without impeding development speed. Continuous testing not only reduces expenses related to redundant testing but also boosts organizational confidence in APIs.
Delivery Velocity: The adage "faster is earlier" holds true in this context. Detecting defects early in the production cycle makes rectification much simpler. Consequently, the time between releases can drastically shrink, leading to improved software quality.
Lower Costs & Higher Revenue: Early and frequent API testing substantially diminishes remediation costs as flaws can be addressed before posing risks in production. Automated testing ensures that new releases are bug-free and less likely to require future rework, allowing developers to swiftly meet customer needs and, in turn, boosting revenue.
Increased Satisfaction: A primary advantage of the shift-left strategy lies in the prompt delivery of software with fewer flaws. This enables products to maintain a competitive edge or even enhance their lead in the market by meeting customer expectations and delivering outstanding customer experiences.
Types of Shift-Left Testing
Shift-Left Testing approach contributes to quicker identification of defects, improved collaboration between development and testing teams, and ultimately leads to the delivery of higher-quality software. Several types of Shift-Left Testing methodologies are employed in the software development process:
Unit Testing:
Unit testing involves testing individual units or components of a software application in isolation. Developers perform unit testing to verify that each unit of code functions as intended.
Example: In a web application, a unit test might validate the functionality of a specific JavaScript function responsible for form validation.
Integration Testing:
Integration testing assesses the interactions between different units or components to ensure they work together seamlessly. This type of testing helps identify issues that may arise when integrating various modules.
Example: In an e-commerce platform, integration testing could involve verifying that the shopping cart module integrates correctly with the payment processing module.
API Testing:
API testing validates the communication and data exchange between different software components. It ensures that APIs function correctly and consistently.
Example: For a weather application, API testing may involve verifying that the application accurately retrieves and displays weather data from an external API.
Component Testing:
Component testing focuses on testing individual components or functional units of an application to ensure they meet specified requirements.
Shift-Left Performance Testing:
Performance testing, usually performed later in the development cycle, can be shifted left to identify and address performance-related issues early on. This includes assessing how the application behaves under different load conditions.
Example: Running performance tests on a web application to ensure it maintains responsiveness and stability when subjected to varying levels of user traffic.
How to Implement Shift Left Testing Approach?
If you have a micro-services architecture, a shift-left testing approach becomes by default the best testing approach and something you can easily put in place. Your team has done the hard work in splitting your central code base into several smaller, distributed code-bases to accelerate development. All that you now need to do is adopt a testing practice that can test these code-bases independently.
Consider the benefits:
In a micro-services architecture , services are loosely coupled that give devs the freedom to make and deploy changes to each of these services independently.
A shift-left approach tests these commits one at a time, independent of the dependent services or alongside them, but providing quick bit-sized feedback on what can be fixed immediately.
Here's a standard step-by-step guide to follow when implementing shift=left testing, but it is all dependent on the organization and your company’s need first.
👉Integrate Early Testing into Development
Embed Testing in Development: Incorporate testing as part of the development phase, not as an afterthought.
Encourage Developer Testing: Motivate developers to perform unit testing and static code analysis as they code.
👉Adopt Agile Methodologies
Agile Frameworks: Implement Agile practices which inherently support early and continuous testing.
Frequent Iterations: Break down the development into smaller, manageable iterations with testing in each phase.
👉Embrace Test Automation
Select Appropriate Tools: Choose automation tools that align with your technology stack and team skills.
Automate Routine Tests: Focus on automating repetitive and high-volume tests to save time and resources.
👉Implement Continuous Integration (CI)
Set Up CI Pipeline: Establish a CI pipeline that integrates code changes regularly and triggers automated tests.
Immediate Feedback: Ensure the team gets immediate feedback from automated tests to quickly address issues.
👉Collaborate and Communicate
Cross-Functional Teams: Foster collaboration between developers, testers, and other stakeholders.
Regular Meetings and Updates: Maintain constant communication channels for quick resolution of issues and sharing of insights.
👉Test-Driven Development (TDD) and Behavior-Driven Development (BDD)
Practice TDD: Encourage writing tests before code, ensuring every new feature has corresponding tests.
Implement BDD: Use BDD to develop features based on user behavior and requirements, integrating testing into the development narrative.
Read more - TDD vs BDD: A Complete Comparison Guide
What are the Challenges of Shift-Left Testing?
Shift-left testing, while advantageous for software development, presents unique challenges.
A significant hurdle is the cultural shift it demands. Traditionally, development and testing roles are distinct, but shift-left testing blurs these lines, requiring developers to incorporate testing into their workflow. This change in practice can face resistance and necessitates a mindset shift across the team.
Another challenge is the need for upskilling. Developers often require additional training in testing methodologies, which can be a steep learning curve. Moreover, the implementation of new tools and technologies for automated and continuous testing presents technical challenges, necessitating careful selection, integration, and maintenance.
The design and upkeep of effective test cases are also critical. Tests need to be robust, maintainable, and adaptable to early stages of development. Poorly designed tests can lead to ineffective testing outcomes, hindering the development process rather than facilitating it.
Additionally, maintaining a balance between speed and thoroughness is essential. While shift-left aims to expedite development by early defect detection, it can become a bottleneck if not implemented efficiently, especially where automation is limited and manual testing is necessary.
Shift-Left with HyperTest
Shift left testing with HyperTest enables teams to develop more quickly and find & fix vulnerabilities prior to production. Since it is integrated with your CI tools and tests every build before deployment, it guarantees that developers can keep an eye out for vulnerabilities early in the software development lifecycle.
✅HyperTest using its CLI can integrate natively with any CI tool used for automated releases, and tests every new change or update in the application automatically with a new PR or commit as the trigger. Click here to learn more about HyperTest’s way to shift-left testing.
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