How Behavior Driven Development and Testing Can Significantly Help Your Software Delivery?
If you're facing disagreements among stakeholders regarding the anticipated outcomes of user stories, despite their design being complete, vague business requirements are probably the root cause. This problem can impact both those with technical expertise and those without, creating distraction and delay within the project. The BDD methodology was developed to tackle these issues and is explored below.
Let’s first understand what BDD is.
What is Behavior Driven Development (BDD)?
Behavior Driven Development (BDD) is a software delivery approach that centres on the interaction between users and the application functionality as driven by Product Owners, Developers and Testers. The requirements and resultant application is crafted, evolved, and tested with this focus in mind.
A good BDD process generates scenarios and supporting automated test cases that ensure a high-quality application that meets the customers expectations, by incorporating the perspectives and requirements of both technical and non-technical stakeholders.
This approach builds upon TDD and acceptance testing driven development techniques. BDD scenarios that represent user stories or acceptance criteria are expressed using a natural language format and then associated with an underlying automated acceptance test at runtime with the use of tools like Cucumber and Gherkin.
However, it's worth noting that BDD is fundamentally a cognitive team collaboration process rather than a programming language or a tool.
BDD provides many advantages. Primarily, it improves communication between technical and non-technical stakeholders by capturing and documenting scenarios using a language that both sides can fully comprehend. Secondly, it ensures that a suitable approach is established by involving all stakeholders early on in the process, considering diverse perspectives and business requirements.
BDD is especially advantageous for teams working in agile environments with continuous integration and development. By aligning the product's design and test approach at the outset, we can avoid redundant coding and badly implemented requirements during development. Furthermore, BDD helps to maintain application quality and ensure that the application keeps meeting client expectations by continuously discussing functional user journeys or scenarios with the customer.
Also read:- What is cucumber in testing?
How to Implement BDD?
BDD is a structured methodology for requirements elicitation, software development and testing. Tools like Cucumber with Gherkin can be employed in order to parse a user scenario at test runtime and execute the associated automated acceptance test.
Features and scenarios must comply with a specific syntax and are contained in a .feature file with a Gherkin keyword starting each scenario step. The objective is to document clear natural language user stories and support their future integrity with associated automated tests.
A BDD scenario will most commonly use a Given, When, Then format. This typically entails outlining a specific start condition, carrying out an action and subsequently observing the outcome. Once the features and scenarios have been defined, testing tools like Cucumber for example, can be employed to execute the supporting automated acceptance tests whilst providing test reports that clearly reference the features and scenarios directly, so that the whole team can see the latest quality overview with direct reference to agreed requirements. Although Cucumber was initially developed in Ruby, Java, JavaScript, or Python equivalent libraries are also available.
Testers And BDD: How Should Testers Contribute?
BDD is an interactive team process in which testers play an indispensable role, are engaged from the start and collaborate with the product owner and developer to finalise the features and scenarios based on the requirements being discussed.
“BDD is about improving the conversation and collaboration between developers, testers, and business stakeholders.”
The aptly named “3 amigos” session describes the meeting in which the product owner, developer and tester join forces to determine the language used to draft great quality user scenarios that will be developed and supported with automated acceptance tests.
But most importantly, it is the process of active discussion and the asking of probing questions to explore the anticipated application behavior in certain circumstances - both positive and negative. What happens if this? What happens if that? When all of these scenarios are explored and captured with a common business facing natural language, the development, testing and resultant application quality will be the best it can be.
Testers play a vital role in the BDD process, bringing their valuable knowledge to the table as they have an intimate understanding of the system and can push it to its limits to uncover bugs, errors and edge cases that others might not think of.
Testers with a good pedigree in probing exploratory testing will be excellent contributors when thinking of the edge cases that an application might be required to handle gracefully. During the discussion of potential solutions, testers can offer critical insights into their feasibility.
They can be tasked with the write up of BDD scenarios after discussion has concluded and managing the review and sign off process.
Behavior-driven development positively impacts development and testing delivery by establishing consensus among stakeholders at the outset of the design process. The use of automated acceptance test cases is essential to ensure that any new scenarios or modifications to existing user journeys are adequately proven across multiple test environments.
Also Read: TDD vs BDD
Simple BDD example
Feature: Search functionality on an Ecommerce website
As a user, I want to be able to search for products on the website so that I can easily find what I need.
Scenario: User searches for a product
Given the user is on the homepage
When the user searches for “headphones”
Then the search results page displays the list of relevant products with their prices and ratings.
Scenario: User executes an invalid search
Given the user is on the homepage
When the user attempts to search without entering a search term
Then the search bar is highlighted with an error message "Please enter a search term."
Scenario: User searches for a non-existent product
Given the user is on the homepage
When the user searches for something that the website doesn’t sell
Then the search results page displays the message "No products found matching your search term.”
Conclusion
BDD involves documenting user scenarios in a natural language, human-readable way, greatly assisting requirements alignment between multiple stakeholders.
A typical BDD workflow is a three-step process, where the team (Product Owners, Developers, Testers) drafts user scenarios in a set Gherkin syntax (Given, When, Then), developers craft the feature and then developers and/or test automation engineers automate the associated acceptance test cases.
The testing tools used for BDD automated testing must provide clear test results and traceability to features and scenarios, ensuring that both technical and non-technical stakeholders can examine the test outcomes to understand the continued quality status of the application, directly in line with agreed requirements.
The BDD approach facilitates complete stakeholder collaboration and requirement brainstorming before and during continued cycles of development and testing, ensuring the application will be built to absolutely align with the client's needs.
It's instrumental in agile teams and allows developers, product owners and testers to participate in the design and quality process from the outset.
