Streamlining Unit Tests with Early’s VSCode Extension

Lior Froimovich

Maintaining high-quality code is a constant challenge for developers. As projects grow in complexity, ensuring that every component functions correctly becomes increasingly difficult. This is where unit testing comes into play. Unit tests are essential for verifying that individual pieces of code work as intended, catching bugs early, and ensuring that changes do not introduce new issues. However, writing unit tests can be a tedious and time-consuming task, especially when done manually.

Traditional unit test creation often involves setting up test environments, mocking dependencies, and writing extensive test cases to cover all possible scenarios. This process is not only labor-intensive but also prone to human error.

Developers might overlook edge cases or make mistakes in the test setup, leading to incomplete or inaccurate tests. Moreover, the time required to write these tests can be a significant burden, detracting from the time available to develop new features or fix existing bugs.

In response to these challenges, Early AI developed a VSCode extension designed to simplify and automate the unit test creation process. This extension generates unit tests with just a click, providing a seamless and efficient way to ensure code quality. By automating the tedious aspects of TDD, the extension allows developers to focus on what truly matters: writing efficient and reliable code.

As the co-founder and CTO of Early AI, with over 20 years of experience in writing code and managing several R&D teams, I have seen firsthand the struggles developers face in maintaining high-quality code. This extension is a culmination of my extensive experience and understanding of the developer’s needs.

Writing a New Feature

Test-Driven Development (TDD) is often touted as the gold standard for producing robust and maintainable code, but let’s face it – implementing TDD can be cumbersome. My approach usually starts with defining a new method in a class, focusing on its signature and return type. At this stage, I leverage the extension to generate unit tests automatically. The extension sets up the foundations for these tests by:

• Mocking the class constructor parameters and method parameters.

• Instantiating necessary concrete objects.

• Creating tests for method invocation and edge cases I might overlook while coding.

writing a function with signature, return type, and no implementation. Click the code lens and let the extension do its work
Example1: Test suit is generated by Early AI with best practices in mind. See the nested describes with the required Mock objects.

Check the above createTodoSignitureOnly() method on our sample todo-app. and the generated TDD tests here.

Fixing a Bug

When it comes to fixing bugs, the TDD approach becomes a major time saver. Once I’ve pinpointed the bug, my first step is to generate tests for the affected method if none exist. Again, describing the method’s functionality and the nature of the bug in comments leads to better test generation. This approach often produces a red test that captures the bug before I even start fixing it. Achieving a failing test before development ensures the bug is accurately addressed, embodying the true essence of automated TDD.

Example2: this is the same test suite as above. The second nested describe is for“edge cases”. BTW, 2 of the tests were failing because of bugs in my Todosample app.

Handling Private Functions

Occasionally, a bug or feature requires modifications to private functions. Since the extension only generates tests for public functions, I temporarily make these private functions public to generate the necessary tests. This strategy is a huge time saver, allowing me to debug smaller pieces of code without navigating through the entire codebase to locate the issue.


Incorporating Early AI’s VSCode extension into my workflow has revolutionized my development process. Whether I’m writing new features or fixing bugs, the extension saves time and enhances code quality. By automating the tedious parts of TDD, it allows me to focus on what truly matters: writing efficient and reliable code. If you’re looking to streamline your development process and embrace TDD without the hassle, give this extension a try. You might find it as indispensable as I do.

This is my first blog for Early AI, and I am excited to share the tools and techniques that have made a significant impact on my development journey. With over two decades of experience, I can confidently say that innovations like this extension are game-changers in the world of software development.

You can see a full example at GitHub. Feel free to generate these tests yourself by looking up EarlyAI’s extension in the VS Code Marketplace here.

Lior Froimovich, Co-founder and CTO

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