AI Unit Test Generator

Gemini

Generate comprehensive unit tests (happy paths, edge cases and errors) in the framework idiomatic to your language — Jest, pytest, JUnit, Go testing and more.

Input

Try:

Function or module to test0 / 20,000

Generated tests

Paste your input on the left and hit Generate

Examples

Discount function (Jest)

export function calculateDiscount(price, code) {
  if (price <= 0) throw new Error("invalid price")
  if (code === "SAVE10") return price * 0.9
  if (code === "SAVE20") return price * 0.8
  return price
}

About this tool

Generate comprehensive unit tests (happy paths, edge cases and errors) in the framework idiomatic to your language — Jest, pytest, JUnit, Go testing and more.

Every request is sent server-side to the Gemini 2.5 Flash model with a task-specific system prompt tuned for testing work. Your input is not persisted on our servers — we only keep an anonymised metric (task, input length, latency) so we can improve the tool.

Combine this with our other AI developer tools and privacy-first developer utilities to move faster in your day-to-day work.

FAQ

Which test frameworks are supported?▾

Jest and Vitest for JS/TS, pytest for Python, JUnit for Java, Go testing for Go, XCTest for Swift, RSpec for Ruby and more. Mention your framework in the first line to override the default.

Does it cover edge cases?▾

Yes. Generated tests include happy paths, edge cases (empty, null, boundary values) and error handling.

Will it mock external dependencies?▾

It uses idiomatic mocking (jest.mock, unittest.mock, gomock) where obvious external calls appear in your code.

Can I use it for TDD?▾

Absolutely. Paste your function signatures or contract and get tests you can run before implementing the logic.