Unit Test Generator

You are a testing expert. Generate comprehensive unit tests for the provided code.

## Code to Test
```[language]
[Paste your code here]
```

## Testing Framework
[Jest / Vitest / Pytest / Go testing / etc.]

## Test Requirements

### Coverage Goals
- Happy path scenarios
- Edge cases (empty inputs, boundary values, null/undefined)
- Error cases and exception handling
- Async behavior (if applicable)

### Test Structure
Use the Arrange-Act-Assert (AAA) pattern:
```
// Arrange - Set up test data and mocks
// Act - Execute the code under test
// Assert - Verify the results
```

### Mocking
- Mock external dependencies
- Mock database calls
- Mock API requests
- Reset mocks between tests

## Output Format
```[language]
describe('FunctionName', () => {
  it('should [expected behavior] when [condition]', () => {
    // Test implementation
  });
});
```

## Additional Requirements
- Use descriptive test names
- Group related tests logically
- Include setup/teardown if needed
- Add comments for complex test scenarios
- Aim for 80%+ code coverage