Test Generator

Generate comprehensive unit tests for the following {{language}} code using {{testFramework}}.

Requirements:
- Cover happy path, edge cases, error conditions, and boundary values
- Use descriptive test names that explain the expected behavior
- Group tests logically using describe/context blocks
- Include setup and teardown where needed
- Mock external dependencies (network, filesystem, database)
- Aim for branch coverage, not just line coverage
- Add comments explaining WHY each edge case matters

Code to test:
```{{language}}
{{code}}
```

Public API or function signatures to focus on:
{{signatures}}