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Posted on • Originally published at idavidov.eu

From Frustration to Automation: How I Built a Gemini-Powered Test Case Generator App

📱 In the world of software development, Quality Assurance (QA) professionals are the guardians of quality. We spend our days ensuring applications are robust, reliable, and ready for users. But let's be honest—a lot of that time goes into writing test cases. It's crucial work, but it can be repetitive and time-consuming.

What if we could change that? What if we could harness the power of Artificial Intelligence to handle the repetitive tasks, freeing us up to focus on what humans do best: critical thinking, exploratory testing, and understanding the user experience on a deeper level?

That's the core idea behind a tool I built: the Test Case Generator. It’s a simple web app designed to empower QAs by using Google's Gemini API to automate the creation of a full suite of test documentation from a single user story.

🤔 The "Why": An Itch I Had to Scratch

Like many projects, this one started with a personal frustration. I had developed a "Master Prompt" that was effective for generating test cases with AI. The problem? My workflow was a tedious cycle of copy-pasting the prompt, manually inserting the user story, and then carefully extracting the output.

It was pain in the eyes. I knew there had to be a better way. As a QA with a passion for development, I decided to Vibe Code the solution myself. The goal was to create a straightforward interface that did all the heavy lifting for me—and for my fellow QAs.

✨ What Does It Do Exactly?

The Test Case Generator is a wrapper for the Gemini API, designed specifically for the QA workflow. You provide three simple inputs: your API key, the application's domain, and the user story.

In return, the app generates a comprehensive set of documents critical for any project:

  • Software Requirements

  • Unclear Requirements (with clarification questions for stakeholders)

  • Integration Tests

  • Functional Tests

  • End-to-End (E2E) Tests

  • API Tests

🚀 The Value Proposition: Your New AI Test Partner

The real magic is in the output. Instead of just a list of test steps, the app provides a structured foundation for your entire testing strategy.

  • Clarify Ambiguity Before It Becomes a Bug: The generated Software Requirements and Unclear Requirements are a game-changer. The AI interprets the user story and immediately flags potential gaps or vague statements, even suggesting the exact questions to ask stakeholders. This tackles ambiguity early, preventing costly rework down the line.

  • Build a Comprehensive Test Suite: The tool doesn't just give you one type of test. It provides a multi-layered suite:

    • Functional & API Tests to verify the core logic and data exchange points.
    • Integration Tests to ensure different components or modules communicate correctly.
    • E2E Tests to validate the complete user journey from start to finish, mimicking real-world scenarios.

This automated generation saves countless hours and helps ensure you have broader test coverage, catching edge cases you might have missed.

⚙️ How to Get Started in 4 Simple Steps

I designed the app to be as user-friendly as possible. Here’s how you can go from a user story to a full test suite in minutes:

  1. Provide Your API Key: First, you'll need a Google Gemini API Key. The app will store it in your browser's localStorage for future use, so you only have to enter it once.
    Landing Page Screen

  2. Select Your Domain: Choose the domain of the Application Under Test (AUT) from the dropdown menu. If your domain is not presented, sorry, you will have to type it in the input filed, that is loaded when you select Other from the Dropdown.
    Other Domain Input Screen

  3. Paste the User Story: Copy and paste the user story you're working on into the input field.
    Domain and User Story Input Screen

  4. Click Generate: Hit the "Generate Test Cases" button and wait for the AI to work its magic. The output will be neatly organized and ready for you to use.
    Output Screen

⚠️ A Note on Honesty: Current Limitations

This is the first release of the Test Case Generator, and transparency is key. You should be aware of a couple of things:

  • It currently only works with a Gemini API Key.

  • The quality of the output depends heavily on the quality of the built-in prompt and, most importantly, the clarity of the user story you provide. A well-written story will yield much better results.

  • You absolutely have to check every single word, the AI outputs. You can’d blindly trust anything.

👇 Your Turn to Save Time

The goal was to build a tool that solves a real-world problem for QA professionals. It’s about spending less time on the mundane and more time on high-impact activities. Now, I invite you to try it out for yourself.

Ready to give it a spin? Try the Test Case Generator now:

"A bad system will beat a good person every time." – W. Edwards Deming

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