What is BDD ?

Behavior-Driven Development (BDD) is a software development process that aims to bridge the gap between technical and non-technical stakeholders by describing the behavior of a system from the user's perspective. BDD tests, also known as acceptance tests, are used to validate that the software meets the requirements specified in the behavior descriptions. BDD involves creating human-readable, scenario-based descriptions of a system’s behavior. These scenarios are written in a language called Gherkin, which is a business-readable syntax for writing acceptance tests. There are two main approaches to BDD testing: manual testing and automated testing. Manual testing involves a human tester executing the tests manually, using a tool such as Postman to send requests to the application and verify the responses. This approach is suitable for testing small-scale applications, or for testing the user interface of an application. However, it can be time-consuming and prone to human error. Automated testing, on the other hand, involves the use of tools and scripts to automatically execute tests and verify the results. This approach is suitable for large-scale applications, or for testing complex behavior that would be difficult to test manually. Some popular tools for automated BDD testing include Cucumber, JBehave, and Behat. One popular tool for manual BDD testing is Cucumber, which allows users to write scenarios in a natural language syntax known as Gherkin. These scenarios can then be run manually by a tester to ensure that the system behaves as expected. There are many tools and platforms available for BDD testing, including: SpecFlow: SpecFlow is a BDD tool that is specifically designed for .NET projects. It allows developers to define test scenarios in Gherkin and run them using the Visual Studio testing framework. Behat: Behat is a BDD tool that is written in PHP and supports the creation of automated acceptance tests. It allows developers to define test scenarios in Gherkin and run them against the application. Cucumber: Cucumber is a popular open-source tool for BDD testing. It uses a simple language called Gherkin to define behavior scenarios, which can then be run against the codebase to ensure that the desired behavior is implemented. Cucumber is available for a variety of programming languages, including Java, Ruby, and Python. JBehave: JBehave is an open-source BDD testing tool for the Java platform. It uses the Gherkin language to define behavior scenarios and integrates with a variety of build and test tools, including Maven, Gradle, and Jenkins. Behave: Behave is a BDD testing tool for Python. It uses the Gherkin language to define behavior scenarios and integrates with a variety of testing frameworks, including nose and pytest. In addition to these dedicated BDD tools, there are also many automated testing frameworks that support BDD-style testing. These include tools like Selenium, which is a browser automation tool, and Appium, which is a mobile automation tool. To give you an idea of how BDD testing works in practice, let's consider a simple example. Suppose we are building a website that allows users to search for books by title or author. We might use BDD to specify the behavior of the search feature as follows: Feature: Search for books As a user I want to be able to search for books by title or author So that I can find the books I'm looking for Scenario: Search for books by title Given the user is on the homepage When the user searches for "Pride and Prejudice" by title Then the search results should include "Pride and Prejudice" by Jane Austen Scenario: Search for books by author Given the user is on the homepage When the user searches for "Jane Austen" by author Then the search results should include "Pride and Prejudice" by Jane Austen These scenarios can be implemented as automated tests using one of the BDD tools or frameworks mentioned above. For example, using Cucumber, the tests might look something like this: @search Scenario: Search for books by title Given the user is on the homepage When the user searches for "Pride and Prejudice" by title Then the search results should include "Pride and Prejudice" by Jane Austen @search Scenario: Search for books by author Given the user is on the homepage When the user searches for "Jane Austen" by author Then the search results should include "Pride and Prejudice" by Jane Austen The "Given" and "When" steps would be implemented as automation code that navigates to the homepage and performs a search, while the "Then" step would use an assertion to verify that the expected results are displayed. In addition to automated BDD tests, it is also common to perform manual BDD testing. This involves manually verifying that the software behaves as expected by executing the behavior scenarios described in the Gherkin feature files. Manual BDD testing can be especially useful for exploratory testing and testing complex scenarios that are difficult to automate For automated BDD testing, these tools allow users to write scenarios in a similar manner to Cucumber, but they also provide the ability to automate the execution of the scenarios. This can save time and reduce the risk of human error in testing. There are several benefits to using BDD in your testing efforts. Some of the main benefits include: One of the main benefits is that it allows for better communication between developers, testers, and stakeholders. By using a common language and set of examples, everyone is able to understand the behavior of the system and what is expected of it. BDD also helps to ensure that the system is tested thoroughly and that all relevant scenarios are considered. Improved communication: BDD allows business stakeholders to clearly communicate their expectations to the development team in a language that is understood by both parties. This helps to reduce misunderstandings and ensures that the final product meets the needs of the business. Increased collaboration: BDD promotes collaboration between all team members, including business stakeholders, developers, and testers. This helps to ensure that everyone is on the same page and working towards a common goal. Faster feedback: BDD allows developers to get feedback on their code earlier in the development process. This helps to identify issues and fix them before they become major problems. Enhanced documentation: BDD scenarios can serve as documentation for the system, providing a clear and concise description of how the system is expected to behave. There are a few best practices that you should follow when using BDD in your testing efforts: • Keep scenarios simple and focused: It is important to keep your scenarios simple and focused on a single behavior or feature. Avoid trying to test multiple behaviors or features in the same scenario. • Use concrete examples: Instead of using abstract examples, use concrete examples that are specific to your business domain. This will help to ensure that your scenarios are easily understood by business stakeholders. • Use Gherkin keywords consistently: Gherkin has several keywords that are used to define the structure of a scenario. It is important to use these keywords consistently to ensure that your scenarios are easy to read and understand. • Don’t forget about edge cases: It is important to consider edge cases, or situations that are outside the norm, when writing your scenarios. This will help to ensure that your system is robust and can handle unusual situations. However, there are also some potential disadvantages to BDD. One issue is that it can be time-consuming to write and maintain a large number of scenarios, especially if the system is complex. Additionally, some people may find it difficult to write scenarios in the natural language syntax used by tools like Cucumber. As an example of BDD, consider a simple shopping website. One scenario for this system might be: "As a customer, I want to be able to add items to my cart so that I can purchase them. Given that I am on the homepage And I have selected an item to purchase When I click the 'Add to Cart' button Then the item should be added to my cart And the cart should display the updated item count" This scenario outlines the behavior of the "Add to Cart" feature from the perspective of a customer. It specifies the conditions under which the feature should be tested (e.g., being on the homepage and selecting an item), the action that should be taken (clicking the "Add to Cart" button), and the expected result (the item being added to the cart and the item count being updated). There are also some disadvantages to using BDD testing. One disadvantage is that it can require a significant amount of time and effort to set up and maintain the test environment. Additionally, BDD tests can be fragile, and may need to be updated frequently as the application changes. Here is an example of a simple BDD test written in Gherkin, a natural language syntax used in BDD testing: Feature: User login As a user, I want to be able to log in to the application using my username and password so that I can access my account. Scenario: Successful login Given I am on the login page When I enter my username and password and click the "Login" button Then I should be redirected to the home page And I should see a welcome message This test describes the desired behavior of the application's login feature: when a user enters their username and password and clicks the login button, they should be redirected to the home page and see a welcome message. This test can then be automated using a tool such as Cucumber, which allows for the execution of the test and the verification of the expected results. In summary, BDD is a useful approach to testing that can help to improve communication and ensure thorough testing. It can be applied to both manual and automated testing, and there are many tools and platforms available to support it. I hope this information has been helpful for understanding the basics of BDD testing.