How do you choose between BDD and TDD for automation testing?

Welcome, everybody, to my automation testing blog on methodologies and tools, which allows broad-ranging discourse. As an experienced software developer with a strong bias for quality and efficiency, I have navigated the elaborate testing frameworks and platforms. 

In this blog post, I will share what has been coming through a long experience in Test-Driven Development (TDD) and Behavior-Driven Development (BDD) practices. I got introduced to LambdaTest, an AI-powered test orchestration and execution platform, recently, and here’s how it started bridging the gap between these practices. 

Understanding Test-Driven Development (TDD):

Being one of the core fundamentals, Test-Driven Development (TDD) remains a pivotal stand for my approach to software development. Guided by the principle of tests written before code is laid down, TDD provides a structured way of ensuring software systems are reliable and functional. The process of TDD, characterized by the cycle Red-Green-Refactor, has guided me through numerous iterations of development while fostering the kind of mindset inclined to disciplined testing and iterative improvement.

Red-Green-Refactor cycle

Red Phase: This initial phase involves writing a failing test that precisely describes the behavior or functionality to be implemented. The articulation of what is expected upfront helps developers know clearly what should be implemented and therefore set up clear targets for the next development cycle.

Green Phase: With the failing test in place, the next step is to write the simplest code that fulfills the requirements outlined in the test. This “thin” or minimal implementation should satisfy test conditions and return a passing result, forming the basis for all future development efforts.

Refactoring: Once the test passes successfully, the code undergoes refactoring to improve its design, readability, and efficiency. Therefore, it has a continuous process of iterative refinement to make the codebase clean, maintainable, and adaptable to any change in the future.

By applying the TDD flow to my project, I observed a difference in code quality, testing coverage, and the speed of overall development. 

Exploring Behavior-Driven Development (BDD):

BDD Testing Defined: Using a test-first philosophy, developers apply proactive validation and continuous improvement to produce high-quality, resilient, and highly change-resistant software products. 

In my purposeful aspiration to achieve better coordination and agreement with stakeholders, I implemented the concept of Behavior-Driven Development (BDD) fully into my work as a complementary way to TDD. BDD expands the testing scopes beyond technical validation to general business definitions and user expectations. BDD is written in a human-readable language and structured syntax that imitates communication and common meaning for cross-functional teams.

The BDD workflow follows a clear and intuitive structure:

Given Phase: his step establishes the initial context or setup for the test scenario, defining the preconditions necessary for the desired behavior. This means that it must be clearly given what the beginning point of the test is, which helps stakeholders understand certain assumptions and dependencies.

When Stage: The ‘When’ describes, to sum up, the specific action/event that initiates behavior under test. At that moment of realization, which becomes the triggering element for change, the system will shift from one state to another as a response to information stimuli.

Then phase: This phase defines the end state expected as a response to that action. After observing that, a stakeholder can see if the system completes its purpose and fulfills the acceptance criteria defined.

Through the structured framework of BDD, I could see how teams transformed their outreach with different stakeholders because of better collaboration and, hence, communication. By using the same language and sharing requirements with all levels, BDD induces alignment and direction to yield good testing practices and, hence, a higher quality of software outputs.

Pros and Cons of BDD:

BDD, as a practice while automating tests, holds several advantages:

  • More collaboration is created among stakeholders, developers, and testers, who share the understanding of needs.
  • Specifications are written in natural language, ensuring a fluent, easy-to-read style for documentation of desired behaviors.
  • Focusing on behavior rather than implementation details encourages a better relationship with business objectives, thereby delivering software that more effectively fulfills user expectations.

However, BDD is not without its challenges:

  • In some cases, whereas the BDD tools and frameworks need an initial setup and have a learning curve, teams shifting from traditional development methodologies might find them punitive.
  • BDD is also meant to actively involve and engage all stakeholders, and this may result in the need for changes in corporate culture.
  • The overhead of maintaining and updating these behavioral specifications for your system as it evolves may overload your team, or it might just be a documentation nightmare.

Here, BDD works really well despite the above challenges:

  • This demands the greatest possible coordination between the technical and non-technical members of a team.
  • The key point is to define and verify requirements, keeping the application user-driven to reflect business objectives.
  • Since the project involves many changes or modifications, an elastic testing approach that can be easily managed is required.

Pros and Cons of TDD:

The following are the benefits of adopting TDD for testing automation:

  • It is an iterative process that enables progressive development while improving the software by approaching higher code quality and maintainability.
  • It identifies problems and design flaws from the testing quite early, thus conditioning a culture of quality assurance and continuous integration.
  • With serious testing practice, it detects defects and design flaws at a very early stage of software development, thus creating a quality-assuring and continuously integrated type of culture.

However, TDD also creates its own headache:

  • Strict adherence to such a discipline of writing the test before code becomes tiresome—and, in fact, compares poorly with software developers used to traditional methodologies.
  • The time investment required for rigorously sticking to the TDD cycle, particularly in the initial development stages, can be perceived as slowing down software development.
  • This can easily lead to over-testing or tests that do not significantly complement the testing suite, making the test suites bloated and with high maintenance overheads. 

TDD proves particularly useful in the following scenario 

  • when project requirements are very strict about software quality assurance, and as such, a suite of strong unit tests will be needed to verify individual components’ behavior.
  • A more test-driven approach utilized by the development team focuses on the origination of tests before the code to drive its design and implementation.
  • Abundance: Rapid feedback and iteration enable developers to iterate quickly and react efficiently to changing requirements and user feedback.

Factors Influencing the Choice Between BDD and TDD:

In fact, factors defining the selection of either BDD or TDD tend to be numerous and hugely influential in defining the ground rules according to which testing will be carried out. As one gets exposed to various development platforms and several project requirements, some major considerations come into play that act as the backbone of this choice.

Project Requirements: A project shall begin with an assessment of the overall requirements and objectives, hence laying down the initial groundwork that identifies the right methodology of testing to be put into use. Projects more suitable for human collaboration and stakeholder involvement may lead to BDD, while those oriented toward technical rigor and code maintainability may traverse closer to the principles of TDD.

Technical Considerations: The project’s technical environment—including the programming language and some parts of the architecture—provides considerable input for deciding the test methodology. Generally, a given language or framework might fit one methodology more than the other, meaning judgment on compatibility and practicality needs to be exercised cautiously.

Team Dynamics and Expertise: The composition and expertise of the development team are important when determining whether TDD or BDD adoption would be viable. While teams that have worked with BDD in the past would be more accepting of the BDD approach, those with a huge experience base of working in TDD might not embrace a shift to an unspecified implementation and would want to continue with current comfort levels. 

LambdaTest: Bridging the Gap Between BDD and TDD:

As I endeavored to optimize testing workflows for developers and streamline the development process, I found LambdaTest to be a transformative solution bridging the gap between BDD and TDD methodologies. LambdaTest is an AI-powered test orchestration and execution platform that embodies complete compatibility testing with features and integrations designed for all scopes in modern software development teams.

LambdaTest supports the BDD and TDD frameworks and provides a clear means of integrating most other test practices. With support from Cucumber, Jasmine, and Mocha, among others, writing tests that are meant to be run on LambdaTest feels like home.

Since the infrastructure is cloud-based, the platform’s agility encourages different teams to conduct tests easily across most browsers, operating systems and device farms. This flexibility ensures that software testing is carried out thoroughly and with consistent results across different testing environments, helping build the team’s confidence in releasing high-quality products.

LambdaTest has strong reporting and analytic capabilities that help gain insights into test executions and performance. Fast issue resolutions are supported to make informed decisions within seconds of raising any problem. This is centralization and convenience for so many—testing efforts from a single, consolidated platform facilitate collaboration and efficiency from one screen. This helps drive productivity and speed innovation across the software development lifecycle.


As I reflect on everything I’ve gone through in the realms of TDD, BDD, and LambdaTest, it dawns on me the transformative impact arising due to automated testing on usual practices developed for software development. By embracing proactive validation and collaboration-rooted methodologies, there is a potential in teams that add new efficiencies along with fostering quality and resilience within their software products.

Whether implementing a greenfield project or working with an existing legacy codebase, both TDD and BDD provide a sense of direction on testing strategies and guarantee improvement. With LambdaTest in a position to adapt and act as the flexible testing platform that it is, teams get the best of both worlds, integrating their preferred methodologies into the rigorous testing process.

As we chart the course ahead in the ever-evolving landscape of software development, let us embrace the ethos of automation testing as a catalyst for innovation and excellence. By fostering a culture of experimentation, collaboration, and continuous learning, we can harness the transformative power of automation testing to build a brighter future for software development. Happy testing!


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