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Shift Left Testing Explained

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The term “shift left” expresses movement. It can describe the movement of an entire team or individuals. What does it do in a project or an entire development lifecycle? Putting it simply,  it reflects the position of testing on a timeline.

Shift Left means testing earlier in the development process. It also means repositioning the engagement, development, and testing efforts towards the customer.

Typically, in a traditional (waterfall) model of software making, testing lands at the end of the pipeline or is one of the last phases of the process. Bringing testing at the very last stage usually causes many problems such as:

  • delays in the deployment
  • a lot of bugs at the end of the development lifecycle
  • bugs discovered just before or after the release to production
  • lack of collaboration between developers and testers through the entire process.

Poor software quality is one of the most harmful consequences of all of these pains listed above.

At first, the team members do not communicate with each other and they fail to communicate the problems early.

It must not necessarily be a bug; sometimes there is some issue with the application setup, there is no testing environment, access to certain resources (such as specific tooling or external software providers), the task description is vague, or the team setup is incorrect.

If communicated and fixed earlier, the entire process can be smoother and cause less frustration in the team. It also encourages people to focus more on the code quality and to deliver earlier and faster.

Most of those issues can be avoided by changing the style of working and shifting testing efforts at the beginning of the process.

Agile way of working

If you care about the quality of your product, your mindset has probably shifted left already.

This approach is strongly connected with the agile way of thinking and using agile work methods in software projects.

In this setup, testing is an integrated part of the team and accelerates software development at higher quality. As a result, testers can identify bugs sooner, saving time and effort. Notably, the earlier you test, the less expensive bugs are to fix.

T The Seven Testing Principles (ISTQB) tell that testing everything is not possible unless a system or functionality is very simple. In practice, however,  the testing efforts should be targeted appropriately at the risk analysis, techniques, and bugs prioritization rather than be attempted thorough testing.

One of the good methods of approaching testing strategy for a specific application can be the guideline from Agile Testing Quadrants. The quadrants are a taxonomy to help teams plan the testing process and testing activities and make sure they have all the resources they need to accomplish it.

Shift Left approach and DevOps and agile background

With the rise of the DevOps movement, there is an increased focus on delivering automated, continuous improvement. It holds true for development and testing alike.

What is more, Continuous Integration (CI) and Continuous Delivery (CD) are core software development disciplines integrated into the agile software development cycle. The point is to release fully-tested and stable builds early and as often as possible. Development, delivery, and test automation are crucial components of this process.

What it means to “Shift Left”

As mentioned at the beginning, Shift Left testing pushes testing to the “left”, to the earlier stages in the pipeline. This improves software quality and reduces time spent on resolving issues later in the pipeline.

Introducing testing early on the “left-side” of the development process, starting with unit tests and complementing with functional and integration tests is fundamental to making CI/CD happen. But that may not be enough.

The team can go even further: to eliminate unclear and contradicting requirements and improve the end-user experience, it is best to involve test engineers in the clarifying and prioritising application requirements. Test engineers can check the available or newly created requirements or user stories for clarity, consistency, testability, and traceability.

This also improves the shift towards client happiness. An early review of the requirements and spotting the flaws marks an early start of the communication with the end-user.

The Shift Left approach introduces more care and thought exchange concerning the client. The team can be perceived as more proactive and more dedicated to the best quality standards of a project.

Benefits of Shift Left Testing for Agile and Devops teams

Agile teams benefit most from Shift Left Testing in terms of clearer specifications, smoother implementations, earlier testing, and reduced costs. However, Shift Right Testing has more benefits like the ability to incorporate user and system feedback based on real usage scenarios.

In opposition to testing early, Shift Right can provide an additional context to the testing scenarios. Shifting right means testing at the end of the process, typically when the software is deployed to production (the post-production environment).

It is performed by a group of experts or selected end-users. It can utilize testing methods such as API Monitoring, using Feature Toggles, or measuring the performance of a live application.

This helps to understand the application better and discover some other flaws that could have been omitted earlier.

Nevertheless, when quality comes first:

  • developers spend more time on coding because they discuss potentially good solutions - they do not investigate who pushes the code first into production without testing

  • there are Unit Tests beside the application code, available and maintainable

  • there is an infrastructure that allows testing before pushing to production, usually the entire team is responsible for the process health

  • there is room for improvement and mistakes

  • developers pair up to catch obvious errors on the fly and learn from one another

  • teams estimate tasks together, taking quality and risks into account

  • potential risks in the systems are spotted and minimized rather than left alone

And finally - the application is tested - not only by one automated or manual test  but by a set of different functional and non-functional scenarios.

The tests are regularly reviewed, adjusted, and observed. This approach introduces a new way of working and highlights the value of testing.

Benefits of the Shift-Left Testing approach

The idea of shift left testing is simple to understand but hard to implement in the development cycle. It is worth the effort though, especially when the team and the entire organization understands the main benefits of this approach, such as:

  • Lower costs - as explained above, bugs detected earlier are less expensive to fix.

  • Increased efficiency in the software development process.

  • Improved product quality and reliability because more bugs are detected at earlier stages.

  • Reduced time to market since the QA process covers the entire development cycle, not only its’ last phase.

  • A competitive advantage gained by letting development teams move fast, build and defend their credibility by innovating in iterations.

Get started with “Shift Left” Testing in Agile

How to approach the change and switch to early software testing? Here is the basic list:

  1. Plan

Shape development in a way that is friendly to Shift Left testing. Once the requirements have been established, developers and testers should ideate how to shape the coding and software testing as early as possible.

Depending on the product expectations as well as the limitations of the team, specific strategies, such as involving testers in the project since the planning phase or using the TDD approach, might have to be crafted to accommodate the Shift Left way of working.

2.** Review the requirements**

It is best to verify not only the existing code but also all the requirements necessary for the code to be written. Early verification can spot obvious mistakes.

  1. Use Static Code Analysis

Static code analysis is the practice of checking the code without executing it. It runs through the basic code structure and ensures that the code is aligned with many standards and guidelines. By following the approach the team can early detect:

  • Programming errors

  • Violations of commonly followed coding standards

  • Syntax anomalies

  • Security issues

A static code analysis is best done via automation. The software should scan all untested codes in a project before it moves to the test phase.

  1. Collaborate

As in any other agile testing technique - early software testing requires a lot of collaboration with the team: Developers, Product Managers, Business Analysts, and other stakeholders responsible for the overall product.

Everybody needs to understand the value of the Shift Left approach and spot the difference after some time of the new process introduction because as a result, the client benefits from better software quality and receives a lovable product.

Conclusion for Left Shift Testing in test automation

There are a number of benefits to left shift testing in test automation. One of the primary benefits is that it helps to identify defects earlier in the development cycle. This means that defects can be caught and addressed before they become more complex and costly to fix. In addition, left shift testing can help to reduce the overall time and effort required for testing by identifying and addressing issues earlier in the process.

Another benefit of left shift testing in test automation is that it can help to improve the quality of the software being developed. By identifying and addressing defects earlier in the process, developers can ensure that the software they are creating is of higher quality and meets the requirements of the end-users.

One of the keys to successful left shift testing in test automation is to incorporate testing into the development process from the very beginning. This means that testing is not an afterthought or an additional step at the end of the development process, but rather an integral part of the development process itself. Test automation tools and frameworks can be used to automate testing activities and make it easier to incorporate testing into the development process.

It is also important to involve testers in the development process as early as possible. This allows them to provide feedback and identify potential issues before they become more complex and difficult to fix. Testers can also work with developers to ensure that the code being developed is testable, and that the testing process is efficient and effective.

Overall, left shift testing is an important approach in test automation that can help to improve the quality of software, reduce testing time and effort, and identify defects earlier in the development process. By incorporating testing into the development process from the very beginning, developers and testers can work together to create software that is of higher quality and meets the needs of the end-users.

Happy (automated) testing!

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Kinga Witko

Engineering Manager | Tester | Tech Blog

Professional Quality Evangelist, experienced in testing web and mobile applications.

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