BDD vs TDD: Pros and Cons

Posted by: admin September 19, 2023 No Comments

This blog focuses on describing different testing methods like Behavioral Driven Development (BDD), Test-Driven Development (TDD). It will likewise help to explain the key contrasts between these methods. Before the finish of this blog, one is required to see how every technique functions, key contrasts and their specific jobs in the development procedure.

BDD and TDD are testing approaches where BDD focuses on the behavior of an application for the end user while TDD aims at how functionality is executed.


In TDD (Test Driven Development), the test is composed to check the execution of functionality, however as the code advances, tests can give bogus outcomes. BDD (Behavior Driven Development) is likewise a test-first methodology, however contrasted by testing the genuine behavior of the framework from the end users point of view.


In spite of the fact that we state BDD is a superior methodology, we should not overlook that BDD has really developed from TDD, as an approach to take out the shortfalls of TDD. So there is positively no mischief in actualizing the two methodologies – one to help the quality of the code the developer composes, and the other to help the conduct of the framework characterized by the product proprietor.

Now we will further discuss BDD and TDD with their pros and cons in detail below.

What is TDD?

TDD refers to Test Driven Development. TDD is used to design and develop the tests for the functionality of the product. We don’t have to write duplicate code if we are working with TDD. If an automated test case fails then the developer has to write the new code.
The purpose of TDD is to make code bug-free, simple and clearer. The work of TDD is to fix the failed test cases before writing the new test cases. It is also called Test First Development.

How To Perform TDD Test

  1. Add a test
  2. Run all Tests
  3. See if any new test fails
  4. Write some code
  5. Run test and refactor code
  6. Repeat


Pros of Test Driven Development

  • It’s very easy to test the test cases written in the TDD. IT understands the principles of good modular design.
  • The architecture of the code is also good. If you want your code to be testable, It should be in proper structure. So we are writing the code and we will not face any architectural code.
  • TDD permits us to break the negative input loop and keep up a steady expense of progress.
  • TDD code never goes out of date because you are running your code all the time.
  • If you want to change something in your code then it’s very easy when you are writing the code in the TDD. It provides the clearity to write the code.
  • It provides you to write the unit test before writing the code so it’s easy to make some changes in your code. If you want to change a code which was written two years ago is hard. But if that code was written in unit tests then it made it easy to change the code.
  • It also helps the programmer to understand the code.
  • You don’t need the unnecessary dependencies to set up your project and it writes the code in small steps which makes the design of code better to understand.
  • It requires a clear understanding of the code so that programmers can understand the code and make the required changes in the code.
  • You can start testing while writing your code. It makes your program more effective.


Cons of Test Driven Development

  • The tests are dependent on external dependencies. So they cannot maintain themselves.
  • The tests are hard to write because the code is more complex to write and understand.
  • The development of the code is slow. The rapid development of code is not possible because we have to write the test cases first, But it long term the development is very fast.
  • The code of TDD is hard to understand as we know writing a code and writing a code well is different. The functionality of TDD is also not discussed, so many team leads only focus on code coverage and it does not tell you anything about code coverage.
  • Sometimes we need the whole team when we are writing the unit test cases.
  • It is not easy for anyone to learn, especially when someone is trying to learn it on their own. So it requires the efforts to learn it and takes more time.
  • There are lots of misunderstandings which stops the person from learning it.
  • If we want to refactor in an early stage then we have to refactor the test classes as well.
  • If the whole team is not maintaining the tests then there is a change of system degrade.
  • Concentrating on the fundamental plan now and not thinking ahead can mean major refactoring prerequisites.


What is BDD?

In software development, BDD refers to Behavior Driven Development, it is a software development approach. It is an Agile programming development procedure that supports joint effort among designers, QA and non-developers or marketing members in a product . It is written in shared languages and improves the communication between technical and non-technical teams.

It permits the tester/market analyst to develop test cases in easy text language like English. The easy language utilized in the situations helps even non-technical colleagues to comprehend what is happening in the software project.

The BDD focuses on business value which customers get from the software. It also saves the time for the developer to develop the program.

Why use BDD Framework?

The basic role of BDD methodology is to improve correspondence among the partners of the task with the goal that each component is accurately comprehended by all individuals from the group before the development process begins. This assists with recognizing key situations for every story and furthermore to eliminate ambiguities from prerequisites.

TDD may not have the capacity to indicate the specific behavior, however you accomplish higher caliber with programming code.

BDD is the way to remove the communication gap between technical and non-technical teams because in BDD we write test cases in simple text. This process involves the output, entities, events that the user cares about.

Pros of Behavior Driven Development (BDD)

  • The BDD uncovers additional capabilities and complexities from the project. As it identified the scenarios in the start so there is less rework at the end of the project.
  • It is the domain specific language that focuses on the domain of your business and it is also important for defining the project specifications. It avoids misunderstandings and improves the communication.
  • As the details specifications are written in the starting and we write tests before the code. So this is the plus point for the BDD as the developers only need to focus on implementing which makes the test cases pass. So the developers do not focus on other features
  • The involvement of the tester starts from the starting of the project life cycle, specification phase. Testing is a backout task and it only comes to play when there is a physical product to test. Testers have the analytical talent and can start from the starting of the project.
  • The product Owner has knowledge of what we need to deliver as a piece of functionality. The pieces of functionality are broken down into pieces that are much more easy to use. This makes the development of the project much easier and removes the complexity of the project in the earlier stages.
  • “Shift left” is a popular expression for testing early in the development procedure. Testing prior means less bugs later. In BDD, test case definition inherently turns out to be a piece of the necessities stage (for waterfall) or prepping (for Agile). When conduct situations are composed, testing and automation can theoretically start.


Cons of Behavior Driven Development (BDD)

  • Creating the Scenarios and maintaining the files needs lots of effort and time. So it is not good for a short project which we need to complete in a short interval of time. But for a long term project it’s worth using the BDD approach.
  • We need good communication between the person who is developing the automation code and the person who is writing the features files. Person who is writing the automation needs these files and scenarios for developing the automation script. If they Don’t have a mutual understanding of the files then it’s hard to develop the project.
  • It defines test data which makes it easier to create automated test cases but when used to execute test cases it raises the problem when the test environment is never left in a known state. The test cases are dependent on the external data often causing the problem when we execute the test cases
  • It is very hard to convert Given statements into setup instructions and scripts that puts the system into the known state before the When statements are executed.
  • You need to create the document for the BDD project because there are many files and scenarios which need to be understood so that we create a documentation.
  • The main drawbacks of BDD are two-fold. Since correspondences between the client and the developer are basic, if the client is not available, it will be hard to work past ambiguities and questions created by the client stories.


Comparison between BDD and TDD

Parameters TDD BDD
Definition TDD is a development technique that concentrates on the working of a feature. BDD is a development technique that aims at the behaviour of the system.
Contributors Developers Developers, QAs, Customers
Language It is written in a language which is alike used for feature development like – Java, Python, etc. Simple English, Gherkin
Focuses on Unit tests Requirement Understanding
Tools JDave, Cucumber, JBehave, Spec Flow, BeanSpec, Gherkin Concordian, FitNesse Gherkin, Dave, Cucumber, JBehave, Spec Flow, BeanSpec, Concordian

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