Development
AI Unit Test Generator — Generate Tests for Your Code Instantly
Paste a function and get ready-to-run unit tests covering normal cases, edge cases, and errors. Less boilerplate, better coverage.
What is Unit Test Generator?
Cobain AI's Unit Test Generator writes unit tests for your code in seconds. Paste a function or class, choose your testing framework, and the AI generates test cases that cover the happy path, edge cases, and error handling. It's a fast way to raise coverage, catch regressions, and skip the boilerplate — whether you write in JavaScript, Python, or another popular language.
Key features
Tests from your code
Paste a function or class and get a ready-to-run test suite that exercises it.
Edge cases included
Covers happy paths, boundary values, empty inputs, and error conditions, not just the obvious case.
Popular frameworks
Generates tests for Jest, Vitest, Mocha, Pytest, JUnit, and other common frameworks.
Many languages supported
JavaScript, TypeScript, Python, Java, C#, and more — just tell the AI your stack.
Readable, structured tests
Produces clearly named tests with arrange-act-assert structure you can extend.
Faster coverage
Bootstrap a test suite quickly, then refine it instead of starting from scratch.
How it works
- 1
Paste your code
Drop in the function or class you want to test.
- 2
Choose a framework
Pick your testing framework and language so the tests fit your project.
- 3
Generate and run
Review the test cases, copy them in, and run them against your code.
Perfect for
Frequently asked questions
Is the unit test generator free?
Yes. You can start generating tests for free with a Cobain AI account, with paid options for heavier usage.
Which testing frameworks are supported?
Common frameworks like Jest, Vitest, Mocha, Pytest, and JUnit. Just mention the one you use.
Which languages does it support?
Popular languages including JavaScript, TypeScript, Python, Java, and C#. Tell the AI your language for the best result.
Does it cover edge cases?
Yes. It aims to cover happy paths, boundary values, empty inputs, and error handling, not just the simple case.
Are the tests ready to run?
They're ready to copy in for most cases, but review them and adjust imports, mocks, and setup to match your project.
Will it reach 100% coverage?
It gives you a strong starting point and good coverage, but you should review the tests and add cases specific to your logic.
Ready to try it?
Create your free account and start in seconds.
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