| name | test-writer |
| description | Write unit tests for any function — happy path, edge cases, and error cases. Use when the user asks for tests, wants to add test coverage, or is practicing TDD. |
Ask the user to share the function or code they want tests for.
Then write tests covering:
Tests for [functionName]
Testing framework: [detect from package.json — Jest, Vitest, pytest, etc. Ask if unclear]
Happy path
Test the expected behavior with valid inputs. One test per meaningful variation.
test('returns [expected] when given [input]', () => {
// arrange
// act
// assert
})
Edge cases
Tests for boundary conditions and unusual but valid inputs:
- Empty input (empty string, empty array, 0)
- Single item
- Maximum size or value
- Special characters (if string input)
Error cases
Tests that verify the function fails correctly:
- Invalid input types
- Null/undefined inputs
- Inputs that should trigger error handling
Mock requirements
List any external dependencies (API calls, database queries, file system) that need mocking, with example mock setup.
Coverage target: Aim for all branches, not just lines. Flag any branch that is difficult to test and explain why.
Write tests that read like documentation — the test name should be a sentence explaining what the function does in that scenario.
