Cucumber: What it is and Best Practices for Test Automation

In the realm of software development, testing quality and efficiency are crucial for ensuring the delivery of robust and reliable products. This is where Cucumber comes into play, a tool to assist teams in how they approach automated testing.

In this article, we’ll delve into what Cucumber is, its origins, its relationship with automated testing, and why it has become a popular choice among developers and testers.

What is Cucumber?

Cucumber is a software testing tool that supports Behavior-Driven Development (BDD). Its primary goal is to enable effective and clear communication between technical team members and non-technical stakeholders. It allows software requirements to be written in natural language, understandable by all involved parties, including developers, testers, and business teams.

The tool was originally developed by Aslak Hellesøy in 2008 to support BDD in Ruby. It quickly gained popularity due to its innovative approach to software testing. Since then, it has expanded to support various other programming languages and has become an essential tool in many agile development processes.

Cucumber’s purpose

Cucumber employs a specific language called Gherkin to describe software behavior. Gherkin is a simple, descriptive language that details system behavior without delving into implementation details. Scenarios written in Gherkin serve as living documentation and as a basis for automated tests.

Cucumber features

• Reading and executing specifications in natural language allows non-developer team members to understand what is being tested.
• It supports multiple programming languages, including Ruby, Java, and JavaScript.
• Integration with testing tools such as Selenium for UI testing or mock and stub frameworks for service testing is possible.

Cucumber and Automated Testing

As we mentioned, the main function of Cucumber in the context of automated testing is to serve as a BDD tool. Here are the details of this primary function:

Translating requirements into automated tests

By using the Gherkin language to write test scenarios in natural language, Cucumber allows business requirements, expressed as expected system behaviors, to be directly converted into automated tests. The scenarios written in Gherkin describe what the software should do, not how it should do it.

Facilitating communication

By using a natural and understandable language to describe tests, it facilitates communication among developers, testers, and business stakeholders. This ensures that everyone on the team understands what is being tested and what the acceptance criteria are.

Executing tests and validating behaviors

After writing the scenarios in Gherkin, Cucumber can be used to execute these tests against the software. It verifies if the software behaves as described in the scenarios and reports any discrepancies between the expected and actual behavior.

Through these functions, the tool will ensure that the developed software is aligned with the needs and expectations of the end user, promoting greater quality and customer satisfaction. It integrates requirements specification, documentation, and testing processes into a single cohesive approach.

What is BDD?

Behavior-Driven Development (BDD) is a methodology in software development aimed at enhancing Test-Driven Development (TDD) practices by integrating agile specification techniques. Conceived by Dan North in the 2000s, BDD focuses on understanding and implementing the desired system behavior from the perspective of the end user, starting with clear and detailed definitions of expected behavior under various conditions based on user requirements.

Just like Cucumber’s primary focus, BDD places a central emphasis on communication and effective collaboration between developers and non-technical stakeholders, such as product managers and clients. The methodology achieves this by using a natural and domain-specific language to describe test scenarios, enabling all involved parties to understand and discuss system requirements and behaviors without delving into technical aspects.

Furthermore, it supports specification by example, using concrete scenarios to detail system behavior. These scenarios are transformed into automated tests, ensuring that the software not only meets technical requirements but also delivers the most relevant and valuable functionalities to the user. Thus, tests written before functional code development serve as a solid foundation for software construction.

In summary, BDD is an approach that aims not only to produce correctly functioning software but also software that precisely fulfills the necessary and expected functionalities for users. By emphasizing clear communication, collaboration between teams and stakeholders, and continuous value delivery, BDD establishes itself as an essential methodology for software development aligned with user needs and market expectations.

The Relationship Between BDD and Cucumber

Tools like Cucumber play a significant role in BDD by enabling automation of these tests. These scenarios, written in a high-level language, ensure that the system behaves as specified while serving as living documentation of the project. Here’s how this relationship works:

Natural language for specifications

BDD focuses on creating clear specifications of the expected system behavior, using concrete examples to describe how the software should function in various situations. Cucumber facilitates this approach by allowing these specifications to be written in Gherkin. This enables non-technical people, such as business stakeholders, to understand and contribute to test documentation.

Facilitating communication and collaboration

One of BDD’s main goals is to improve communication among developers, testers, and business personnel. Cucumber helps achieve this goal by transforming behavior specification into natural language into automated tests.

Automating tests

BDD promotes test creation before code development. Cucumber is the tool that allows these tests to be automatically executed. When the code is implemented, tests written with Cucumber can be used to verify if the software behaves as expected according to the described scenarios. This not only ensures software quality but also helps ensure that it meets the actual needs of users.

Living documentation

BDD test scenarios serve as living documentation of the system. Cucumber reinforces this characteristic by allowing these scenarios to be easily read and understood by anyone. As tests are continually updated to reflect changes in code and requirements, documentation remains relevant and useful over time.

In other words, while BDD is a software development methodology that emphasizes the importance of specifying system behavior clearly and comprehensibly, Cucumber is a tool that makes this specification a practical reality. Together, they help build a common understanding of the software under development, ensuring that it meets the expectations of end users and business stakeholders.

Cucumber Benefits

The use of Cucumber in writing specifications offers significant advantages that enhance the development process and communication within teams. The main feature we’ve already mentioned throughout this content is the readability and accessibility of specifications. This clarity promotes a consistent understanding of system requirements and facilitates effective collaboration.

Furthermore, another benefit is that Cucumber plays a crucial role in early validation of requirements. Even before development begins, it enables collecting feedback from business stakeholders, ensuring that the team is aligned with end user expectations and needs. This helps prevent deviations and misunderstandings, ensuring that the developed product aligns with what is truly necessary and expected.

Cucumber also encourages teams to develop and use a ubiquitous language – a common and domain-specific language that all team members use to refer to the system. This strengthens communication and reduces the chances of ambiguity in specifications, facilitating a clearer understanding of the project and business domain.

Another highlight is that specifications written in Cucumber serve not only as guides but also as executable automated tests. This means that documentation is not static; it evolves and validates continuously as the project progresses. This living documentation ensures that information about the system is always up-to-date and reflects the actual behavior of the software.

Cucumber’s Given/When/Then structure, in accordance with the grammar of the Gherkin language, facilitates clear definition of conditions, actions, and expected results.

Example

To further illustrate the effectiveness of Cucumber’s Given/When/Then structure with a different example, consider developing a feature in a task management application. The team wants to implement a new feature that allows users to add reminders to their tasks. Using Gherkin language and Cucumber’s structured format, the scenario could be described as follows:

“Given that I am logged into the Task Management Application and I view the task ‘Submit project report.’ When I select the ‘Add Reminder’ option and set the reminder for ‘December 10th at 2 PM,’ then a reminder is successfully associated with the task, and I receive a confirmation ‘Reminder added for December 10th at 2 PM.'”

In this scenario, the “Given” part establishes the system’s previous state – the user is logged in and has a specific task in mind. The “When” describes the action the user performs, i.e., adding a reminder to an existing task. Finally, the “Then” specifies the expected outcome of this action – successful confirmation that the reminder was added.

This format not only clarifies what the feature should do but also creates a directly executable test that verifies if the application behaves as expected. This simplifies communication among team members and ensures that everyone, from developers to stakeholders, clearly understands the purpose and operation of the new feature. At the same time, it allows effective verification and living documentation of the system’s behavior.

After listing all these benefits, it is clear that using Cucumber as part of the development and testing process not only improves the technical quality of the software but also aligns teams around a common understanding of the project’s objectives, ensuring that the final product is truly aligned with user needs and business goals.

If you are considering this tool, consider an experienced partner to support you on this journey. Objective is a pioneer in automated testing execution, improving operational efficiency, and minimizing bug risk. Talk to ours experts and learn more about our offering and how we can support the use of Cucumber.