What is BDD testing in the software development process?
Every software project starts off with the planning phase, where the different functionalities based on stakeholders' requirements are finalized. In terms of software development, the behavior of an application refers to how the functionalities perform in real-world scenarios, along with their deviations, from the initial context of planning for the software system.
The test scenario details the expected behavior via a user story—a simple description of the application's feature from the user's perspective. The test scenario and executable specification—requirements in the form of tests that can be executed—is generally created using Gherkin, which uses plain English text with a simple syntax. BDD tools for testing don't require expertise in programming languages; any member of the project can create test cases or analyze existing test cases to collaborate better.
BDD testing framework
BDD frameworks facilitate software testing by providing the structure needed for assessing business needs with executable scenarios. Each BDD testing framework incorporates user stories to offer more precise guidance, which enables the teams to write better tests for the software solutions. There are various BDD tools available on the market that make use of BDD testing frameworks, with the help of Gherkin syntax.
Feature files contain the feature, scenarios, and psuedo-code needed for BDD testing. Once they're created, teams can start using relevant tools to test for the desired behavior.
When to use BDD testing
BDD testing is more effective when implemented after extensive testing or after the initial set of tests has been carried out by the QA team. Since the BDD process involves the business and product teams, functionalities should be in working order before creating test scenarios based on the user story. While BDD testing is more suitable for acceptance tests, some of the other compatible testing types are:
Manual regression testing
Manual regression testing involves the iterative process of manually repeating the same set of tests with multiple modifications. Minor changes in the BDD test cases don't require extensive coding skills and time, making it easier to run tests.
UI testing
UI testing requires testing of the user interface to assess if everything works as intended, both visually and on the backend.
Exploratory testing
Exploratory testing is used for testing a feature at random. The behavior of the feature and its functionalities can then be assessed thoroughly.
Advantages of BDD testing
Improved collaboration
Collaboration isn't restricted to QA and development teams—even business teams can have access to the test scenarios and test scripts. This level of collaboration ensures effective communication that helps address the concerns and input of all business stakeholders.
Easier testing
BDD testing isn't complicated and doesn't require any coding expertise when compared to other testing types.
Minimal documentation
BDD testing follows a natural flow for executing tests and doesn't require extensive documentation.
Less maintenance
BDD test files are easy to maintain and require much less maintenance throughout their lifecycle.
Flexibility
The results of BDD tests for individual scenarios are quite comprehensive and capable of accurately identifying the reasons for test failures. These tests also accommodate the partial testing of scenarios, with slight modifications.
Increased test coverage
Behavior-driven development testing encourages comprehensive testing by covering various user scenarios and edge cases.
Challenges of BDD testing
Complicated initial setup
BDD testing requires an extensive setup that can handle fast and effective test creation for different testing scenarios.
Inefficient communication
Test scripts can easily be misinterpreted by the participating teams, since there are multiple functionalities for any given feature.
Maintenance
Any changes to the features in the application have to be conveyed to all of the stakeholders, and the existing test files should be updated to reflect those changes.
Dependencies
BDD testing is made possible by integrations with multiple tools, with each tool catering to a particular stage of testing. Generally, a suite of tools are used for creating test scripts, automating and executing them, and finally analyzing the results.
Limited coverage
The nature of BDD testing has limitations. In spite of its integration with various tools, it's not capable of optimal bug coverage. Edge cases and complex scenarios especially aren't covered. This is why BDD testing is always supplemented with other testing types, either before or after.
Over-optimization
Since testing is easy to implement with Gherkin in BDD testing, teams end up investing more time in tweaking existing tests to attain perfection.
Why choose BDD testing over other testing methods?
BDD testing offers a lengthy list of advantages, and there are some notable reasons to choose it over other testing types:
Better coverage
BDD tests can be performed alongside basic tests for different types of testing, essentially adding an extra layer of testing based on the input from different stakeholders. Additional conditions for each scenario are covered in the tests, which contribute to error coverage that might not be uncovered in other tests.
Faster test creation
Even if BDD testing doesn't cover all scenarios, once there's an understanding of the syntax, it's easier to create the tests from scratch. BDD testing has a simple syntax with a short learn curve, so creating tests from scratch is easy.
Steps for BDD testing
Discovery
In this stage, the stakeholders engage in structured conversations to discuss the test scenarios and user stories. Concrete examples offer more precise guidance for both developers and business users to understand exactly what is required from the BDD testing.
Formulation
Based on the user stories, test scripts are formulated with input from all of the stakeholders involved in the project. Generally, a Gherkin-based tool is used for this task or it's integrated with the test automation tool.
Automation
The BDD testing is then automated for efficiency. Test files created inside a third-party tool can be accessed from within the test automation tool.
Example test case for BDD testing
Let's discuss a real-world example of using BDD testing inside an ecommerce application, outlining the entire purchase workflow. The following example, and every other scenario in BDD testing, can be improved with the use of test automation.
- Feature: Purchasing a product inside an application
- Scenario: The user checks if the product is available for purchase and adds it to the cart. The user then proceeds to buy it, after adding the address and payment details to complete the purchase
- Given: The user has a registered account with payment and address details
- When: The user's login credentials match with the database record
- And: The product can be added to the cart
- And: The product is deliverable to the default address
- Then: The product is added to the cart
- And: The user updates the quantity of the product in the cart
- Then: The product quantity is updated in the cart
- And: The Buy Now button is visible
- And: The user's delivery address is available in the account
- And: The user's payment details are available for use
- Then: The user can complete the purchase
With a full-stack testing tool like Zoho QEngine, behavior-driven development testing like this can be easily achieved for better coverage, tight-knit functionalities, and easily understandable tests.
Conclusion
BDD testing is associated with assessing the application based on its behavior when different actions are carried out by a user. The test scripts are easy to create and maintain; each test script can be used to cover a different aspect of the functionalities. And since BDD testing doesn't depend on domain-specific language, and is easier to perform with user stories, its benefits trickle down even to the end user documentation.
And to make the process run even more smoothly, integration with a versatile test automation tool can help with running multiple tests in succession, eliminating human error, and maintaining consistency.