What Is Shift Left Testing?
Shift left testing is a software testing approach that emphasizes moving the testing process earlier in the software development life cycle (SDLC). The term “shift left” refers to the notion of shifting the testing activities towards the left side of the project timeline, meaning they are conducted earlier rather than later in the development process.
The goal is to identify and resolve issues more quickly, improve overall software quality, enhance collaboration between team members, and reduce time to market and associated costs.
This is part of a series of articles about application security testing.
In this article:
- Benefits of Shift Left Testing
- How a Shift Left Testing Strategy Works
- Best Practices of Shift Left Testing
Benefits of Shift Left Testing
There are multiple benefits to shifting testing to the left:
Reduced Costs Involved in Development and Testing
Shifting testing to the left helps identify and fix issues earlier in the development process, which typically reduces the costs involved in development and testing. Early bug detection and resolution often require fewer resources and less time, resulting in lower overall expenses. Fixing issues later in the development process can be more complex and time-consuming, increasing the cost of remediation.
Early Bug Detection Ensures Better Code and Product Quality
By performing tests early and frequently, shift left testing enables developers to catch defects and issues as soon as they occur. This early bug detection helps ensure that the code is of higher quality, as issues are resolved before they can compound or cause additional problems. As a result, the final product is more reliable, stable, and less prone to defects, leading to increased customer satisfaction and reduced support and maintenance costs.
Enhanced Test Coverage
When testing is performed later in the development process, time constraints can lead to incomplete or inadequate test coverage. In contrast, shift left testing allows for more comprehensive test coverage, as testing activities are integrated throughout the development process. This expanded coverage helps identify a wider range of issues, from functional defects to performance and security vulnerabilities, further improving the overall quality of the product.
Effective Use of Time and Resources
Shift left testing promotes the efficient use of time and resources by encouraging collaboration between developers, testers, and other stakeholders. Early involvement of testing teams in the development process fosters a shared understanding of requirements and expectations, allowing for more effective planning and execution of testing activities.
Continuous feedback loops and automation help minimize repetitive tasks, allowing team members to focus on more critical aspects of the project. Ultimately, this effective use of time and resources can result in faster development cycles and more efficient use of project resources.
Related content: Read our guide to IAST
How a Shift Left Testing Strategy Works
A shift left testing strategy involves integrating testing activities earlier in the SDLC and employing a continuous approach to testing and deployment. Two key components of this strategy are continuous testing and continuous deployment
Continuous testing involves running automated tests throughout the entire development process to ensure that the software remains in a releasable state at all times. This approach provides immediate feedback on the quality and functionality of the code, allowing developers to quickly identify and address issues.
Continuous testing typically includes the following aspects:
- Unit tests: Focus on individual components or functions of the software, ensuring that each part behaves as expected.
- Integration tests: Verify that different components of the software work together correctly, identifying any issues that may arise when the components are combined.
- System tests: Evaluate the software as a whole, ensuring that it meets overall requirements and behaves correctly in its intended environment.
- Performance tests: Measure the software’s response times, throughput, and stability under various workloads, ensuring that it meets performance requirements.
- Security tests: Identify potential vulnerabilities and ensure that the software adheres to security best practices.
Continuous deployment is the practice of automatically deploying code changes to production as soon as they pass the required tests. This approach allows new features and bug fixes to be released more quickly, reducing the time it takes to deliver value to customers.
Continuous deployment typically involves the following steps:
- Code changes are committed to a version control system (e.g., Git).
- Automated tests are run against the changes, verifying that they do not introduce any new issues or break existing functionality.
- If the tests pass, the code changes are automatically deployed to a staging environment, where further testing and validation can take place.
- If the changes pass all tests and validations in the staging environment, they are automatically deployed to production.
Implementing a shift left testing strategy with continuous testing and continuous deployment helps ensure that software is of high quality, stable, and secure. This approach also promotes faster development cycles, more efficient use of resources, and improved collaboration between team members.
Learn more in our detailed guide to mobile app security testing.
4 Best Practices of Shift Left Testing
1. Identify & Plan Testing Life cycle
Planning the testing life cycle early in the development process is crucial for a successful shift left testing approach. This involves defining the testing scope, objectives, and expected outcomes, as well as identifying the types of tests needed and the tools required to execute them.
Proper planning helps ensure that testing activities are aligned with project goals and that they provide the desired level of coverage and depth. Additionally, planning helps identify potential challenges or constraints and enables teams to allocate resources and time effectively.
2. Specify Quality Standards
Establishing clear quality standards and expectations from the outset is essential for a shift left testing strategy. These standards should be well-defined, measurable, and agreed upon by all stakeholders, including developers, testers, and product owners.
By specifying quality standards early on, teams can better align their testing efforts with project goals and ensure that the final product meets the desired level of quality. Quality standards may include aspects such as performance benchmarks, security requirements, and functional specifications, as well as adherence to coding best practices and industry standards.
3. Offer Continuous Feedback
One of the key benefits of shift left testing is the ability to provide continuous feedback to developers throughout the development process. This feedback is essential for identifying and resolving issues quickly, improving the overall quality of the code and product.
To facilitate continuous feedback, it’s important to create a culture of open communication and collaboration between team members. Encourage developers and testers to work closely together, share insights and knowledge, and address issues as they arise. Regularly review test results and use them to inform development decisions, and leverage tools that enable real-time monitoring and reporting of test progress and outcomes.
4. Embrace Test Automation
Automated tests should be run quickly and frequently, providing immediate feedback on code changes and allowing developers to catch and fix issues early in the development process. Automation also helps reduce the manual effort required for testing, enabling testers to focus on more complex or high-priority tasks.
To make the most of test automation, invest in tools and frameworks that support the project’s specific needs, and prioritize automating tests that are repetitive, time-consuming, or prone to human error. Additionally, ensure that all automated tests are maintainable and scalable, and regularly review and update them to keep pace with evolving requirements and standards.
Application Security Testing with Bright
For a robust AppSec programme, it is important to ensure that security vulnerabilities are detected and remediated early and often. With agile development and CICD, security testing needs to shift left and into the hands of developers.
To succeed, you need to adopt developer friendly tools like Bright’s DAST scanner, built from the ground up to enable developers to own the security testing process, with the following key features:
- Developer first – built for DevOps / CICD
- Test everything – WebApps and APIs (SOAP, REST, GraphQL)
- Accurate – NO false positives
- Automation – integrated automatic validation of findings removes manual validation bottlenecks that stifle your release cycles and compound your technical and security debt
- Feedback Loop – Easy to use, fast scans and integrates across your pipelines
- Easy fixes – Developer friendly remediation guidelines, start fixing security issues early and often
- Detect more – automatic Business Logic vulnerability detection