TDD Made Easy

Lior Froimovich

How to Use AI to Simplify and Accelerate Test Creation

Experienced developers have seen first-hand the importance of TDD. But that doesn’t mean they have to like it. TDD is often perceived as a rigid and time-consuming practice that creates delays in deliveries. Some studies say that less than 10% of developers and organizations are using TDD, the real number is possibly even lower. As a result, many developers compromise on the types of tests they write, risking software quality.

But with AI, there’s no need to choose between speed, software quality and your peace of mind. In this blog we’ll show how AI-based tools can automate and significantly streamline the TDD process. 

With the AI-based tool, much of the TDD manual effort is automated. By simply providing a skeleton of the code with a description of the functionality, the tool generates the initial set of unit tests in a click. 

This not only saves time but also ensures that the tests cover essential aspects of the functionality. Now you are ready to develop!

Below you’ll find a step-by-step example, you will have a clear understanding of how an AI-based tool can simplify and enhance the TDD process, making it more efficient and less error-prone. This approach not only improves productivity but also results in more reliable and maintainable code.

Introduction

What is Test-Driven Development (TDD)?

Test-Driven Development (TDD) is a software development methodology that emphasizes writing tests before writing the actual code. The process involves writing a test for a specific functionality, seeing the test fail (since the functionality hasn’t been implemented yet), writing the minimal code to pass the test, and then refactoring the code to meet standards. This cycle is repeated for each piece of functionality until the software is complete.

Importance of TDD in Software Development

TDD offers several benefits that contribute to the overall quality and maintainability of software:

1. Improved Code Quality: By writing tests first, developers are forced to think about the requirements and design before implementation, leading to cleaner and more reliable code.

2. Early Bug Detection: Writing tests upfront helps catch bugs early in the development process, reducing the cost and effort of fixing them later.

3. Enhanced Refactoring: With a comprehensive suite of tests, developers can confidently refactor code, knowing that any regressions will be caught by the tests.

4. Better Design: TDD encourages modular and loosely coupled code, as writing testable code often leads to better design practices.

Why is TDD so Painful?

Despite its benefits, TDD comes with its own set of challenges, particularly when it comes to writing unit tests:

1. Time-Consuming: Writing tests before writing the actual code can be time-consuming, especially for complex functionalities.

2. Initial Learning Curve: Developers new to TDD often struggle with the concept of writing tests first and may find it challenging to adapt.

3. Maintaining Tests: As the codebase evolves, maintaining and updating tests to reflect changes can become cumbersome.

4. Writing Effective Tests: Crafting meaningful and effective tests that cover all edge cases requires skill and experience.

Introducing a New Approach: 

Automated Unit Test Generation with an AI-based Tool

To address these challenges and streamline the TDD process, we introduce a new approach: using an AI-based tool to automate the generation of unit tests. This tool leverages advanced algorithms to understand the function signatures and high-level descriptions provided by the developer. It can generate main flow unit tests and later, edge-case tests, understanding code dependencies in other files to create comprehensive and high coverage.

By integrating this AI-based tool into the development workflow, developers can enjoy the code quality benefits of TDD without the overhead of manually writing each test case. This approach not only speeds up the development process but also ensures comprehensive test coverage, making TDD more accessible and practical for developers at all skill levels.

How We’ll Demonstrate the Power of AI-Driven TDD

Demonstrating the Addition of Functionality to a Sample Application

In this blog, we will demonstrate how to add new functionality to a sample Todo and Comment management application. This application currently allows users to manage their todos and comments, providing a solid foundation to illustrate the practical benefits of our new approach to TDD.

We will enhance this application by adding a new feature, guiding you through the entire process step-by-step. You’ll see how to define the function signature, invoke the AI-based tool to generate initial unit tests, implement the functionality to pass these tests, and finally, handle edge cases.

We will walk through the following steps to illustrate this streamlined TDD approach:

1. Writing the function signature with the necessary input parameters and return type.

2. Invoking the AI-based tool with a high-level description of the functionality.

3. Automatically generating basic unit tests for the main flow of the functionality.

4. Implementing the functionality to satisfy these initial tests.

5. Ensuring the tests pass and the main flow is complete.

6. Generating and handling unit tests for edge cases.

7. Refining the functionality to pass all tests, including edge cases.

8. Using the tool to review and provide feedback on the implemented code.

By the end of this demonstration, you will have a clear understanding of how to write TDD tests without the friction or rigidity that accompany the manual TDD process. This approach not only improves productivity but also results in more reliable and maintainable code.

Streamlined TDD Workflow with the AI-Based Tool – Live Example 

In this blog we’ll demo this new approach using EarlyAI, a unit test generation tool that automatically generates quality, working unit tests for your code.

Throughout this exercise we’ll work with this repo.

Planned Enhancements

We will extend the functionality by introducing a new model, Project, which can contain multiple todos. This enhancement involves changes in the Model, Services, Controllers, and Database layers to support the new Project model and its interactions with todos.

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Step-by-Step Implementation

Let’s walk through the implementation of the updateProject function step-by-step, showcasing various aspects of TDD using the AI-based tool.

  1. Writing the Function Signature

The first step is to define the function signature. This includes the name of the function, input parameters, and return type.

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* See the code in GitHub.

2. Invoking the AI-Based Tool

Next, the developer invokes the AI-based tool, providing a high-level description of the functionality.

3. Generating Basic Unit Tests

The AI-based tool generates basic unit tests for the main flow of the functionality. Initially, these tests will fail since the function is not yet implemented.

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* See the tests in GitHub.

We can see 2 tests generated. Tests are failing of course…

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* File in GitHub

4. Coding the Main Functionality

Implementing the main code functionality to satisfy the generated tests.  

* See the full implementation in GitHub.

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5. Passing the Main Flow Tests

Once the main functionality is coded, the tests should pass (turn green). We’re on the right track

.

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6. Generating Edge Case Tests

Invoking the AI-based tool again to generate unit tests for edge cases. These new tests will also initially fail.

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* Full tests in GitHub.

7. Implementing Edge Case Handling

Let’s add the code to handle the edge cases and satisfy the new tests.

* Full implementation in GitHub.

Tests are satisfied, and we’re done.

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Instead of having to write all the tests ourselves, the AI-based tool allowed us to significantly simplify the process.

Conclusion

Benefits of Using TDD with the AI-Based Tool

Using the Test-Driven Development (TDD) approach in conjunction with the AI-based tool offers numerous advantages:

1. Increased Productivity: By understanding function signatures and high-level descriptions, the tool generates initial unit tests automatically. This reduces the time and effort required to write tests manually so developers can focus more on coding the actual functionality. This significantly speeds up the development process.

2. Enhanced Test Coverage: The AI-based tool ensures comprehensive test coverage by generating tests for both main flows and edge cases. This ensures that all potential scenarios are covered, reducing the likelihood of bugs slipping through. In addition, the tool understands code dependencies across different files, creating comprehensive and high-coverage tests that account for the entire codebase.

3. Improved Code Quality: Writing tests first, as mandated by TDD, leads to cleaner, more modular code. The AI-based tool further enhances this by automating the tedious parts of writing tests.

4. Reduced Learning Curve: For developers new to TDD, the AI-based tool simplifies the process, making it easier to adopt and practice this methodology effectively.

Try EarlyAI, the AI-Based Tool, for Yourself

We encourage you to integrate this AI-based tool into your development workflow. Whether you’re a seasoned TDD practitioner or new to the methodology, this tool can significantly enhance your productivity and the quality of your code. By automating the most time-consuming aspects of TDD, it allows you to focus on what matters most: writing effective and efficient code.

Future Early Enhancements and Features

We are continually working to improve the AI-based tool. Future enhancements and features may include:

Support for Additional Languages and Frameworks: Expanding the tool’s compatibility to cover a broader range of programming languages and testing frameworks.

Advanced Test Scenarios: Incorporating more complex test scenarios and use cases to cover a wider array of testing needs.

Integration with CI/CD Pipelines: Allowing seamless integration with continuous integration and deployment pipelines to automate testing further.

User Feedback and Customization: Providing options for user feedback and customization to tailor the tool’s functionality to individual developer needs.

By continually enhancing the tool, we aim to make TDD more accessible, efficient, and beneficial for developers worldwide. Give it a try and experience the transformation in your development process.

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