Генератор юнит-тестов

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

**Requirements:**
- Language: {{language}}
- Testing Framework: {{framework}}
- Follow AAA pattern (Arrange, Act, Assert)
- Include edge cases and error scenarios
- Use descriptive test names that explain the expected behavior
- Mock external dependencies appropriately

**Generate tests covering:**
1. Happy path scenarios
2. Edge cases (empty inputs, null values, boundary conditions)
3. Error handling (invalid inputs, exceptions)
4. Integration points (if applicable)

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

Provide the complete test file with all necessary imports and setup.