Do you ever wonder why some software products exceed the deadlines and some are delivered with flaws? The answer lies in ineffective planning and not testing the program thoroughly.

Software testing is essential to provide effective software; if ignored, it can result in faulty products.

This written piece discusses a testing approach that has made its place in the software development life cycle (SDLC) among many organizations because of its ability to release bug-free apps.

The strategy aims to deliver products and services that are tested often, whose testing starts as soon as possible, and where the testing process is continuous. 

Why Shift-Left Testing?

Traditionally, the software development was sequential, and the testing happened at the end of the project’s timeline. This often resulted in the product being full of patches. Usually, the bugs are introduced in the coding phase.

Testing when the development is complete can push engineers to patch the issues. 

In such cases, the QA should be a continuous process. Continuous testing can render the full potential of any product/service.

This is where shift-left testing plays a vital role. This approach is all about introducing testing processes in the early stages of software development and continuing it throughout the development. With this approach, the testing starts with developers when they write the first line of code.

Benefits of Using Shift-left Testing 




There are several benefits of shift-left testing in software development; some are given below. 
  1. One of the most significant advantages of employing this testing approach is the early detection of bugs. 
  2. It improves software quality because there is continuous testing and validation during the development phase. 
  3. Developers can receive immediate feedback on their code and quicken the time-to-market products by accelerating the development process. 
  4. The approach also helps set up a collaborative environment. Developers and testers start communicating with each other since the beginning of the project by including shift-left testing. 
  5. It works in sync with Agile methodology that focuses on testing every iteration, emphasizing early and continuous feedback, and encouraging collaboration between cross-functional teams. 

How to Include Shift-Left Testing in SDLC?

Specific ways can accelerate the adoption of shift-left testing in your software development. A few such ways are listed below. 

Include Testing Processes in the Early Stages

Testing processes should be included in the early stages of software development as this helps solve issues at a much lower cost. 

In the initial stages, less code is written, meaning fewer dependencies exist. In this phase, the bugs haven’t yet entered the software design but might, if not, be fixed. The testers can troubleshoot them without changing the code. 

Collaboration and Communication

Usually, organizations have separate development and testing teams, but shift-left testing promotes healthy collaboration by removing the silos between these two.

This approach brings the stakeholders, developers, and QA partners together while encouraging daily meetings, and sprint planning sessions between them.

The project benefits from a shared understanding of the user requirements, and a tool (like Slack) that exhibits centralized communication can help in this direction.

Automation 

Continuous testing is challenging with manual efforts alone; the teams need automation testing tools.

Investing in automation testing results in increased speed and optimization of testing operations. For instance, regression testing involves repeatedly examining certain features (like the app's login page) after introducing changes.

Such tasks are monotonous and can result in human errors. Following best practices and carefully choosing the automation tools can be helpful for the project’s success.

Security Practices

The number of developers in any organization outnumbers the number of security professionals. The need for security is dire, given the increasing amount of cyber threats. Shift-left testing emphasizes code scanning by developing a DevSec pipeline, including a scanner to run checks every time a developer issues a pull request. 

Continuous Integration/ Continuous Deployment Pipeline

Creating a CI/CD pipeline helps implement shift-left testing by encouraging continuous testing throughout the SDLC. CI promotes unit testing at every code commit, ensuring the code changes do not hamper the app’s functioning.

CI also helps automate integration testing, build an immediate feedback system, and perform regular static analysis.

CD, conversely, ensures the app's automatic application in different environments and consistency across various environments (using IaC and automated configurations).

Different Approaches to Shift-Left Testing

There are different approaches to shift-left testing, and each one brings several advantages to the SDLC. Four such types are listed below. 

Traditional Shift-Left Testing 

Unlike other methods emphasising unit and acceptance testing, traditional shift-left testing is a standardized approach focusing on unit and integration testing. The approach uses an application programming interface (API) for testing. 

Incremental Shift-Left Testing 

The project is divided into small increments, with each increment being delivered to the end user when using this approach. Testing these small application parts (that are dependent on one another) becomes more manageable and cost-effective. 

Agile/DevOps Shift-Left Testing 

This is more advanced than incremental shift-left testing as it focuses on testing in sprints. This testing is limited to development testing and is not used in operational testing. A sprint usually lasts 30 days, and effective communication is essential to implement this testing type. 

Model-Based Shift-Left testing 

The approach works on models created for the system under testing, such as behavioral, state, or functional models. Several tools and techniques, such as UML diagrams, MBL tools (like Tosca and Conformiq), and state machines, can implement this testing type.

Conclusion 

Shift-left testing aims to find the defects as early as possible rather than waiting until the development is complete.

The approach can be used to examine functional and non-functional aspects of the app. It seeks to accelerate the development process and shorten the time to market by allowing quicker iterations and feedback loops.

Any organization can start with shift-left testing by creating one small team that tests a feature from the beginning. Using behavior-driven development (BDD) can complement your shift-left testing efforts.

Introducing coding standards or static analysis code along with the abovementioned methods can also help implement this testing technique.