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How to Shift Left Testing Across the SDLC

Overview

In the race to deliver high-quality software, traditional testing approaches often create a bottleneck at the finish line. Bugs discovered late in the development cycle lead to costly rework and delayed releases. Shift-left testing flips this script as it advocates for proactive quality assurance throughout the software development life cycle (SDLC).

Shift-left testing offers the benefits of catching defects and addressing them before they snowball into major issues by introducing testing activities earlier in the SDLC. However, as with many software testing approaches, shift-left testing includes several types of testing techniques that must be understood by development teams to be effective.

Read on to learn the how and why of shifting testing left. Explore strategies to enhance development efficiency and software quality.

What Is Shift-Left Testing?

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Finding and fixing security vulnerabilities early is cheaper and less risky.

This involves a range of strategies aimed at incorporating early testing and quality assurance into the software development life cycle. Instead of waiting until the later stages of development to initiate testing efforts, shift-left testing emphasizes the importance of testing earlier in the software development life cycle and in parallel with code development.

When testing is injected early on, development teams can identify and address defects, issues, and potential risks before they propagate further into the development process. By doing so, teams save time, resources, and costs associated with rework and refactoring.

The Importance of Early Testing

Early testing is crucial in the modern software development landscape for several reasons.

First is the obvious one—it enables the early detection and resolution of defects. Addressing defects becomes exponentially more expensive and time-consuming as development progresses. Being able to identify and address issues as early as possible means teams can avoid the compounding effects of technical debt and the costly remediation efforts that often accompany late-stage defect discovery.

Early testing in the development process allows teams to identify and address issues before they become deeply embedded in the application’s architecture. This proactive approach prevents small problems from evolving into more significant, costly challenges and ensures a more stable and robust foundation for the application. By catching defects early, teams can:

  • Streamline development.
  • Reduce technical debt.
  • Deliver higher-quality software more efficiently.

With early testing, teams can adopt test-driven development (TDD) and behavior-driven development (BDD) methodologies, which have been proven to improve code quality, maintainability, and overall software robustness.

Furthermore, early testing brings about collaboration and communication between development and testing teams. Given that testers get involved from the outset, there is a chance they can provide valuable insights, feedback, and expertise during the requirements gathering and design phases, all of which go towards delivering quality software.

 

The Challenges With Traditional Testing Approaches

Traditional or waterfall testing methods are often fraught with several challenges that impact the development efficiency and quality of software products. In the waterfall model, testing occurs after the development cycle leading to five key challenges that bedevil traditional testing approaches:

  1. Late detection of defects. This is one of the obvious issues in traditional testing. Because testing often occurs late in the development cycle, it means defects are discovered much later.
  2. Lack of early feedback. With testing taking place towards the end of the development process, there’s minimal early feedback on code quality and functionality. With this delay comes slow identification of potential issues and improvements, as such, affecting overall project efficiency.
  3. Increased costs. The cost of fixing defects rises significantly the later they are found in the SDLC. Traditional approaches often miss early detection opportunities, leading to expensive bug fixes and possible rework of large code segments.
  4. Limited test coverage. Traditional testing might not cover all possible scenarios and edge cases, especially when a team has a limited time to project delivery. This can result in undiscovered bugs and untested functionalities, leading to lower software quality.
  5. Integration issues. When testing is conducted late, integration issues between different system components could spring up at the end. Developing software is like building a complex machine. Rushing integration testing is like assembling parts late at night—mismatched pieces might work alone but cause trouble when combined, leading to delays and frustration.

The Value of Shift-Left Testing

Shifting testing activities to the left or earlier in the software development life cycle offers numerous benefits that can significantly enhance the overall quality, efficiency, and delivery of software projects. Here are some of the benefits organizations can derive from shift-left testing.

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Early Bug Detection

In software development, time is money. Bugs discovered late in the development cycle can be expensive and time-consuming to fix. Shift-left testing allows for the identification and rectification of defects during the initial stages when they are smaller and easier to address. This trims down the time and resources needed for bug fixes, leading to a more efficient development process.

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Cost Reduction

Building upon early bug detection, shift-left testing ultimately leads to cost reduction throughout the development life cycle. Fixing bugs early minimizes the need for rework, refactoring, and additional testing later. This not only saves development teams time and resources but also helps to avoid costly delays.

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Improved Software Quality

Shift-left testing isn’t just about fixing bugs early. It’s also about building quality into the software from the very beginning. When software development teams commit to testing throughout the development process, they can catch and address potential issues before they become major problems. This leads to a higher overall quality of the software, resulting in a more robust, reliable, secure, and user-friendly final product.

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Faster Time to Market

Today’s software market is very competitive. Getting your product to market quickly can be a significant advantage. Shift-left testing helps accelerate time to market by streamlining the development process. Early identification and resolution of defects prevent delays caused by late-stage bug fixes. Additionally, the focus on continuous testing ensures a smoother transition to deployment, allowing you to deliver your product to users faster.

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Increased Test Coverage

By integrating testing early in the SDLC, teams can expand their test coverage, ensuring that a broader range of scenarios, edge cases, and functionalities are thoroughly tested. This comprehensive approach reduces the risk of overlooking critical aspects of the software, improving overall quality and reliability.

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Agile and DevOps Alignment

The shift-left testing philosophy aligns well with Agile and DevOps methodologies as both emphasize continuous integration, delivery, and feedback loops. Integrating testing throughout the development process facilitates a smoother workflow within Agile and DevOps teams. This fosters a culture of continuous improvement and ensures that quality remains a priority throughout the software development pipeline.

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Increased Developer Productivity

When implemented effectively, shift-left testing can also lead to increased developer productivity. Early feedback from testers helps developers identify and fix bugs quickly, minimizing the need for rework and refactoring later. This allows developers to focus on writing clean, efficient code and delivering new features faster.

Shift Left Development Testing

To embrace the shift-left testing approach, it is crucial to integrate development-level testing activities into the development process. Integrating testing practices such as static analysis, unit testing, and functional and nonfunctional testing directly into development allows developers and testers to find and fix defects early, at their source. The following sections will break down various testing techniques and how they align with a shift-left testing strategy.

The Role of Static Analysis

Shift-left testing thrives on early detection, and static analysis tools are the secret weapon in this proactive approach. Unlike traditional testing methods that require running code, static analysis solutions examine the source code itself, acting like a code detective scrutinizing every line. This meticulous examination uncovers potential bugs, security vulnerabilities, and areas where the code could be written more efficiently.

Static analysis solutions like Parasoft’s C/C++test, dotTEST, and Jtest can be incorporated into development workflows in several ways. Developers can run static analysis scans locally in their development IDEs on their code changes and new feature code before committing them, or they can integrate automated code scans into their CI/CD pipelines to ensure code is scanned each build, allowing for early detection and resolution of issues.

Shifting Static Analysis Into Active Development

To fully embrace the shift-left development testing approach, organizations should integrate static analysis tools directly into their development workflows.

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Code Scans Prior to Code Commits

Developers can run static analysis scans on their code changes before committing them to the codebase, allowing for early detection and resolution of issues. With this, they can be automated as part of the pre-commit hooks or integrated into the development environment, ensuring that no code with potential issues is committed without being analyzed first.

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Continuous Quality Assistant

Static analysis tools such as Jtest or dotTEST can act as a continuous quality assistant, providing real-time feedback and suggestions to developers as they write code, promoting best practices, and encouraging high code quality from the outset. These tools can be integrated into integrated development environments (IDEs) or code editors, providing instant feedback on potential issues, code smells, or violations of coding standards. Given this real-time guidance, developers can learn and improve their coding practices, leading to better code quality and fewer defects.

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Automated Scans in the CI/CD Pipeline

Integrating static analysis code scans into the CI/CD pipeline enhances shift-left defect detection by continuously monitoring code quality throughout the development life cycle. As part of the automated build process, static analysis ensures that every code change is scrutinized for potential defects, security vulnerabilities, and coding standard violations before progressing to further stages. This early and automated feedback mechanism allows teams to identify and address issues promptly, reducing the accumulation of technical debt and preventing defects from advancing into production.

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AI-Enhanced Static Analysis

With the introduction of artificial intelligence (AI) in software development and testing, some static analysis solutions now offer AI-enhanced features to streamline remediation of static analysis findings. Parasoft for example offers AI/ML-based triaging of static analysis findings to help teams prioritize remediation activities, assign violations to developers based on skill sets, and generate code fixes with the click of a button. The acceleration gains AI offers in static analysis help development teams remediate more violations in a shortened time span, which results in more defects and vulnerabilities being addressed in the early stages of code development.

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Unit Testing

Unit testing is a fundamental practice in shift-left development testing. It involves creating and running small, isolated tests that verify the behavior of individual units or components of a software system.

Unit tests serve as a safety net because they ensure that new code changes do not break existing functionality. They also provide immediate feedback to developers, allowing them to identify and fix defects in near real-time, reducing the overall time and effort required for debugging and remediation.

The Importance of Unit Testing

Integrating unit testing solutions into the development workflow can help developers validate their code changes and ensure that each unit or component functions as expected. This proactive approach to testing helps to identify and address issues early, preventing them from compounding and becoming more difficult and costly to fix later in the development cycle.

You can think of unit tests as living documentation for the codebase. Well-written unit tests verify the correctness of the code and provide insight into its intended behavior and usage. This documentation aspect becomes valuable when onboarding new team members or maintaining the codebase over time.

Optimize and Shift Left Test Executions

To leverage the benefits of unit testing in a shift-left development testing approach, teams should optimize and shift left their test executions.

  1. Integrate unit testing frameworks and tools directly into the development environment, allowing developers to run tests continuously as they write code.
  2. Automate unit test execution as part of the CI/CD pipeline to ensure that all code changes are thoroughly tested before being merged into the main codebase.
  3. Optimize the change validation workflow so that developers can run AI-enhanced test impact analysis autonomously in their IDE or on their feature branch, focusing their test executions on the subset of test cases that correlate to code changes.
  4. Explore techniques such as parallelization and test impact analysis to optimize test execution times in CI/CD pipelines and provide faster feedback loops to developers.

AI-Enhanced Unit Testing

AI in unit testing solutions further empowers teams to shift left by automating the creation, execution, and maintenance of test cases early in the development cycle. These AI-driven tools, such as Parasoft Jtest for Java applications, can intelligently:

  • Generate comprehensive test suites.
  • Generate unit tests for uncovered lines of code to drive higher levels of code coverage.
  • Optimize test executions and the change validation process.

This early and proactive approach accelerates the detection and remediation of defects and also increases developer testing and coding productivity.

API and Integration Testing

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In modern software development, applications rarely exist in isolation. They often interact with other systems, services, and APIs, forming intricate integrations and dependencies. Consequently, ensuring the correct integration and interaction between these components becomes crucial for delivering reliable and functional software solutions. This is where API and integration testing plays a vital role in the shift-left development testing approach.

An API testing first strategy helps teams shift left their functional testing by enabling early validation of the core functionalities and interactions between different software components. By focusing on APIs, teams can test the underlying business logic, data processing, and integration points before the user interface is even developed.

Many commercial API test solutions enable teams to leverage API service definition files to generate API component tests. Some, like Parasoft SOAtest, also employ AI to enable teams to generate parameterized API scenario tests from recorded traffic or from service definition files. The ability to leverage service definition files for test creation enables QA teams to start creating test cases in parallel to development.

This early testing ensures that the foundation of the application is robust and that any issues are identified and addressed at the earliest possible stage, significantly reducing the time and effort needed to fix defects later in the development cycle.

Who Owns Integration Testing?

Traditionally, integration testing has been primarily the responsibility of dedicated testing teams or quality assurance (QA) professionals. However, in modern Agile practices, most QA teams are embedded with development, which aligns perfectly with the shift-left development testing model. In a shift-left testing strategy, the ownership of integration testing extends beyond the QA team and becomes a shared responsibility among developers, testers, and other stakeholders involved in the software development life cycle.

Development’s Role in Integration Testing

As advocates of shift-left development testing, developers play a crucial role in ensuring the successful integration of their code with other components and systems. This involvement can take various forms:

Smoke Testing

Developers can implement smoke tests, which are lightweight tests designed to quickly validate the basic functionality and integration points of their code changes. These tests can be executed locally or as part of the CI/CD pipeline.

Contract Testing

Developers can employ contract testing techniques, which involve defining and testing the expected interactions and data contracts between different components or services. This approach makes it possible to catch integration issues early and ensures that all parties adhere to the agreed-upon contracts.

Component Testing

Developers can create and maintain component tests, which verify the behavior of individual components or modules within the broader application context. Component tests ensure that the individual components work properly in isolation, which is required before trying to integrate with other components.

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QA’s Role in Integration Testing

While developers play a key role in integration testing, the QA team’s expertise and involvement remain crucial. QA professionals bring a holistic perspective and can provide valuable insights into the overall system behavior and end user experience. Their responsibilities in integration testing may include the following.

API Scenario Testing

QA teams can develop and execute comprehensive test scenarios that simulate real-world use cases and validate the correct integration and interaction between various APIs, services, and systems. These tests help uncover integration issues that may not be apparent at the component or unit level.

Compatibility Testing

With the proliferation of devices, browsers, operating systems and AI models, it’s essential to validate the application’s compatibility across different environments. QA teams can execute compatibility tests to ensure the integrated system functions correctly on supported platforms.

Performance Testing

Integration testing is an ideal opportunity to assess the performance of the integrated system under various load conditions. QA teams can plan and execute performance tests to identify bottlenecks, optimize resource utilization, and ensure the system meets the expected performance requirements.

End-to-End Testing

QA teams can design and execute end-to-end tests that validate the entire application flow, from the user interface to the backend systems, to ensure seamless integration and data flow across all components.

Shift Left QA Testing

While shift-left development testing emphasizes integrating testing practices into the development phase, the role of quality assurance (QA) teams remains crucial. Shifting testing activities left and embedding QA teams with development enables closer collaboration, provides earlier testing feedback, and allows the entire team to contribute to the overall quality assurance process from the outset. This collaboration bridges the gap between development and testing, ushering in a more cohesive and efficient workflow.

Early involvement of QA teams ensures testing aligns with project requirements and design specifications. QA professionals can provide valuable insights during the requirement-gathering and design phases, ensuring testability is built into the product from the beginning. This alignment helps in creating comprehensive test plans that cover all aspects of the application, including edge cases and potential failure points.

 

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Scalability Challenges

As organizations adopt shift-left testing approaches, QA teams may face scalability challenges. With testing efforts being initiated earlier in the software development life cycle, the volume of tests and the frequency of test execution can increase significantly. This can strain resources, infrastructure, and tooling, potentially leading to bottlenecks and delays in the testing process.

To address these scalability challenges, QA teams need to embrace strategies that enable efficient and scalable testing practices. This may involve leveraging cloud-based testing platforms, implementing parallelization techniques, optimizing test suite execution with test impact analysis, and adopting risk-based testing approaches to prioritize critical areas.

 

What Is a Lean Web UI Test Strategy?

A lean web UI test strategy is an approach that urges QA teams to think critically about what type of test they should create to validate functionality or to meet their testing requirements. Many QA teams overrely on UI and end-to-end testing to validate business logic. However, in many cases testing can shift left from the UI layers to the API layers enabling teams to start their functional testing much earlier in the development life cycle. This is not to say that teams should abandon UI or end-to-end testing as it’s required to validate user interface interactions, end user workflows, and cross-browser compatibility, and more.

Here are some tips for teams adopting a lean web UI test strategy.

  • Think critically about what type of test to create based on the business logic they’re required to validate.
  • Take an API testing first approach. Start creating API tests as soon as a service definition file has been created. Many commercial API testing tools enable the use of service definition files to generate API component tests, and some solutions, such as Parasoft SOAtest, for example, leverage AI to make API scenario test creation easier for less technical testers.
  • Outline the appropriate use cases in which a web UI test should be created and share these guidelines across the team.
  • Analyze old UI test cases as they break to determine if the business logic under test can be validated on the API layers or if maintaining that web UI test case is necessary. If the logic can be validated through the APIs, retire the test case and create an API test scenario to replace it.

 

Benefits of a Lean Web UI Test Strategy

Implementing a lean web UI test strategy can yield numerous benefits for QA teams and the overall software development process. Below are some of the specific benefits:

  • Shift-left testing. By concentrating testing efforts on the API layers, teams can initiate functional testing much earlier since API testing can commence before all application components are fully developed. Leveraging service definitions, teams can generate these tests even before the UI or dependent components are completed.
  • Faster test execution. API tests execute much faster than UI or end-to-end test cases, so by focusing on API testing, teams can get faster testing feedback.
  • Early defect detection. By focusing on API testing and involving QA teams earlier in the development process, teams can identify and address defects and issues promptly, reducing the cost and effort associated with late-stage fixes.
  • More stable and maintainable test suites. In general web UI test cases tend to be less stable and more sensitive to application change resulting in high test maintenance burdens to the QA team. API testing in comparison is less brittle and more stable, resulting in a lower test maintenance cost.
  • Scalability and flexibility. Since API testing facilitates high levels of test automation and scales easily across teams and physical machines, by adopting a lean web UI test strategy, QA teams can have a more robust test automation strategy that easily scales across the enterprise.

API testing solution like Parasoft SOAtest leverage AI to help teams easily adopt a lean web UI test strategy. With the Smart API Test Generator, teams can convert automated web UI test suites in any test framework to API scenario tests for RESTful services. This allows teams to leverage their existing web UI test suite to generate API scenario tests to validate the business logic.

Shift Left Nonfunctional Testing

Shifting left nonfunctional testing involves integrating nonfunctional testing activities, such as performance, security, and accessibility testing, early in the development life cycle.

Moving these tests to earlier phases enables teams to identify and address potential problems before they boomerang out of control. Early nonfunctional testing ensures that the software meets performance benchmarks, security standards, and accessibility requirements from the outset, leading to a more robust and reliable product. This approach also aligns well with Agile and DevOps practices as it promotes continuous iterative improvement.

The Challenge of Late-Stage Nonfunctional Testing

Deferring nonfunctional testing until the later stages of development can pose significant challenges and risks.

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Performance

Conducting performance testing late in the development cycle can uncover critical bottlenecks that require significant rework to resolve. Identifying performance issues early allows for more efficient optimization and ensures the application can handle expected load conditions without compromising user experience or system stability.

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Security Penetration Testing

Late-stage security penetration testing can reveal vulnerabilities that necessitate extensive code changes and reconfiguration. However, when security issues are picked up early in development, it reduces the risk of breaches and ensures that security measures are integrated into the application architecture from the beginning, enhancing overall resilience.

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Web Accessibility Testing

Web accessibility testing performed at the end of development often leads to major redesigns to meet compliance standards. Shifting left accessibility testing allows developers to incorporate accessibility best practices from the start, ensuring that the application is usable by all users, including those with disabilities, without significant last-minute changes.

The Value of Test Reusability

Designing functional tests that can be extended to support other testing methods such as nonfunctional testing, save both time and resources. Reusing existing functional test cases and repurposing them enables teams to start testing for nonfunctional requirements much earlier than traditional workflows. Often nonfunctional testing like performance, security penetration, or accessibility testing are left to the later stages of testing and are conducted by siloed teams. The ability to repurpose existing tests allows Dev and QA teams to become more involved in the validation of nonfunctional requirements and to start testing earlier.

Additionally, reusable tests are easier to maintain and update. When a test case needs to be updated, updates to the functional test case can be applied universally. This consistency ensures all software aspects are evaluated against the same standards, leading to more reliable and high-quality results.

Service Virtualization as a Shift-Left Enabler

Service virtualization is a technique that simulates the behavior of components in a software application, such as APIs, databases, and third-party services, that are not readily available or are difficult to access during development and testing. It creates a virtual environment that mimics the functionality and performance of these components, allowing developers and testers to work independently of external constraints.

Service virtualization plays a crucial role in enabling shift-left testing by allowing teams to start testing much earlier in the development process. It provides virtual representations of unavailable or incomplete components, enabling developers and testers to validate interactions and performance without waiting for the actual services to be developed or become accessible.

This early testing capability helps identify defects and performance issues sooner, reducing the risk of late-stage surprises and the associated costs. In addition, service virtualization supports CI/CD practices by providing stable and predictable testing environments, ensuring that testing is thorough and uninterrupted.

The Benefits of Shifting Left With Service Virtualization

Service virtualization improves test coverage by enabling testing of various scenarios, including edge cases that might be difficult to reproduce with real services. It also reduces costs associated with setting up and maintaining test environments, as virtual services can be easily configured and reused. Additionally, service virtualization fosters a more agile and responsive development process, aligning well with modern Agile and DevOps methodologies.

Optimize and Shift-Left Regression Testing

An effective strategy for optimizing regression testing is to focus the testing efforts on areas of change. Identifying and isolating the code changes or updates can help teams execute regression tests selectively on the affected components and their dependencies, reducing the overall testing time and effort.

This approach can be achieved through techniques such as:

  1. Test impact analysis. Analyzing the code changes and identifying the tests that need to be executed to verify those impacted components and functionalities.
  2. Test suite prioritization. Prioritizing and executing the most relevant regression tests first, ensuring that critical functionalities are validated early in the testing process.
  3. Test parallelization. Leveraging parallel execution of regression tests, particularly for independent and isolated components, to accelerate the overall testing process.

Conclusion

By shifting left testing across the SDLC and integrating testing activities from the inception of the development process, organizations can identify and address defects early, significantly reducing the cost and complexity of remediation. This proactive approach enhances product quality and accelerates delivery timelines, fostering a more agile and responsive development environment.

Parasoft’s Continuous Quality Testing Platform provides teams with a complete end-to-end AI-enhanced solution that enables teams to start testing earlier and to keep testing aligned with the rapid pace of Agile development.

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