Coding Prompts
Write Unit Tests
Generate comprehensive unit tests for any function or module, including edge cases.
Prompt
Write unit tests for the following [LANGUAGE] code using [TEST_FRAMEWORK]. **Code to test:** ```[LANGUAGE] [FUNCTION_OR_MODULE_CODE] ``` Write a comprehensive test suite that covers: 1. **Happy path** — typical inputs that should succeed 2. **Edge cases** — empty inputs, null/undefined, boundary values (e.g., 0, -1, max int, empty string, empty array) 3. **Error cases** — inputs that should throw or return an error, and verify the correct error type/message 4. **Parameterized test** — at least one data-driven test that runs the same assertion across multiple input/output pairs Follow the AAA pattern (Arrange, Act, Assert) with a blank line between each section. Use descriptive test names in the format: `should [expected behavior] when [condition]`.
How to Use
Paste any function, class, or module and get a ready-to-run test file. The generated tests will cover the scenarios most likely to catch real bugs — not just the obvious happy path. Copy the output into your test file and run it immediately; tweak any fixture data that needs to match your actual data shapes.
Variables
| Variable | Description |
|---|---|
| [LANGUAGE] | Programming language (e.g., Python, TypeScript, Java, Go, Rust) |
| [TEST_FRAMEWORK] | The testing framework to use (e.g., pytest, Jest, JUnit 5, testing package for Go, cargo test for Rust) |
| [FUNCTION_OR_MODULE_CODE] | The complete code you want tested — include the function signature, body, and any types or interfaces it depends on |
Tips
- If the code has external dependencies (database calls, HTTP requests, file system access), mention them so the model can suggest the right mocking strategy (e.g.,
jest.mock,unittest.mock,testify/mock). - For TDD workflows, paste just the function signature with no body — the model will write tests first, which you can then use as a spec to drive your implementation.