Unit Test Generator

Generate comprehensive unit tests for the following code. Include:

1. **Happy Path Tests**: Test normal/expected behavior
2. **Edge Cases**: Test boundary conditions and edge cases
3. **Error Handling**: Test error scenarios and exceptions
4. **Mock Data**: Provide sample test data where needed

Use appropriate testing framework conventions (Jest, Mocha, pytest, etc.)

Code to test:
```
[PASTE YOUR CODE HERE]
```

Testing framework preference: [Jest/pytest/JUnit/other]

Generate complete, runnable test cases.