This test suite template provides comprehensive tests for a Python class that employs lazy-loading, covering initialization, dependency injection, logging, error handling, and validation using Pydantic. It ensures the class works as expected in various scenarios.
import pytest
from unittest.mock import Mock, patch, AsyncMock
from lazy_loaded_class import LazyLoadedClass, ExampleModel # Replace with the correct module path
import logging
# Fixtures for mocking dependencies
@pytest.fixture
def mock_dependent_class1():
mock = Mock()
mock.some_method = Mock(return_value="result_from_dependent_class1")
mock.to_dict = Mock(return_value={"dependent_class1_data": "value"})
return mock
@pytest.fixture
def mock_dependent_class2():
mock = Mock()
mock.another_method = Mock(return_value="result_from_dependent_class2")
mock.to_dict = Mock(return_value={"dependent_class2_data": "value"})
return mock
@pytest.fixture
def mock_logger():
with patch('logging.getLogger') as mock_get_logger:
mock_logger_instance = Mock(spec=logging.Logger)
mock_get_logger.return_value = mock_logger_instance
yield mock_logger_instance
@pytest.fixture
def valid_input_data():
return {
"param1": "example_value",
"param2": 42
}
@pytest.fixture
def lazy_loaded_class(valid_input_data):
return LazyLoadedClass(**valid_input_data)
# Test cases
def test_initialization(lazy_loaded_class, valid_input_data):
"""Test that LazyLoadedClass initializes correctly with given parameters."""
assert lazy_loaded_class.param1 == valid_input_data["param1"]
assert lazy_loaded_class.param2 == valid_input_data["param2"]
assert lazy_loaded_class._dependent_class1 is None
assert lazy_loaded_class._dependent_class2 is None
assert lazy_loaded_class._logger is None
def test_logger_lazy_loading(lazy_loaded_class, mock_logger):
"""Test that logger is lazily loaded upon first access."""
# Before accessing, logger should be None
assert lazy_loaded_class._logger is None
# Access logger property
logger = lazy_loaded_class.logger
# After access, logger should be initialized
assert logger is not None
assert logger == mock_logger
logger.debug.assert_called_with("Logger initialized for LazyLoadedClass")
@patch('lazy_loaded_class.DependentClass1')
def test_dependent_class1_lazy_loading(mock_dependent_class1_class, lazy_loaded_class):
"""Test that DependentClass1 is lazily loaded upon first access."""
mock_instance = mock_dependent_class1_class.return_value
# Before accessing, _dependent_class1 should be None
assert lazy_loaded_class._dependent_class1 is None
# Access dependent_class1 property
dependent_class1 = lazy_loaded_class.dependent_class1
# After access, _dependent_class1 should be initialized
assert dependent_class1 is not None
assert dependent_class1 == mock_instance
mock_dependent_class1_class.assert_called_once()
lazy_loaded_class.logger.debug.assert_called_with("DependentClass1 initialized")
@patch('lazy_loaded_class.DependentClass2')
def test_dependent_class2_lazy_loading(mock_dependent_class2_class, lazy_loaded_class):
"""Test that DependentClass2 is lazily loaded upon first access."""
mock_instance = mock_dependent_class2_class.return_value
# Before accessing, _dependent_class2 should be None
assert lazy_loaded_class._dependent_class2 is None
# Access dependent_class2 property
dependent_class2 = lazy_loaded_class.dependent_class2
# After access, _dependent_class2 should be initialized
assert dependent_class2 is not None
assert dependent_class2 == mock_instance
mock_dependent_class2_class.assert_called_once()
lazy_loaded_class.logger.debug.assert_called_with("DependentClass2 initialized")
def test_some_method(
lazy_loaded_class,
mock_dependent_class1,
mock_dependent_class2,
mock_logger
):
"""Test the some_method functionality with mocked dependencies."""
# Inject mocked dependencies
lazy_loaded_class._dependent_class1 = mock_dependent_class1
lazy_loaded_class._dependent_class2 = mock_dependent_class2
lazy_loaded_class._logger = mock_logger
# Call the method under test
result = lazy_loaded_class.some_method()
# Assertions
mock_dependent_class1.some_method.assert_called_once()
mock_dependent_class2.another_method.assert_called_once()
mock_logger.info.assert_called_with("Successfully called methods on lazy-loaded classes")
assert result == {
"result1": "result_from_dependent_class1",
"result2": "result_from_dependent_class2"
}
def test_to_dict(
lazy_loaded_class,
mock_dependent_class1,
mock_dependent_class2
):
"""Test the to_dict method for correct serialization."""
# Inject mocked dependencies
lazy_loaded_class._dependent_class1 = mock_dependent_class1
lazy_loaded_class._dependent_class2 = mock_dependent_class2
# Call the method under test
result = lazy_loaded_class.to_dict()
# Assertions
expected_dict = {
"param1": "example_value",
"param2": 42,
"dependent_class1": {"dependent_class1_data": "value"},
"dependent_class2": {"dependent_class2_data": "value"},
}
assert result == expected_dict
def test_add_dependent_class(lazy_loaded_class):
"""Test dynamic addition of dependent classes."""
mock_new_dependent = Mock()
lazy_loaded_class.add_dependent_class('dependent_class1', mock_new_dependent)
assert lazy_loaded_class._dependent_class1 == mock_new_dependent
lazy_loaded_class.add_dependent_class('dependent_class2', mock_new_dependent)
assert lazy_loaded_class._dependent_class2 == mock_new_dependent
with pytest.raises(ValueError) as exc_info:
lazy_loaded_class.add_dependent_class('invalid_class', mock_new_dependent)
assert str(exc_info.value) == "Unknown class type: invalid_class"
def test_validate_model_success(lazy_loaded_class):
"""Test successful validation of input data against ExampleModel schema."""
valid_data = {"id": "123", "value": 10}
result = lazy_loaded_class.validate_model(valid_data)
assert isinstance(result, ExampleModel)
assert result.id == "123"
assert result.value == 10
def test_validate_model_failure(lazy_loaded_class):
"""Test validation failure when input data does not conform to ExampleModel schema."""
invalid_data = {"id": "123", "value": "not_an_int"}
with pytest.raises(ValueError) as exc_info:
lazy_loaded_class.validate_model(invalid_data)
assert "Invalid data for ExampleModel" in str(exc_info.value)
def test_error_handling_in_some_method(
lazy_loaded_class,
mock_dependent_class1,
mock_dependent_class2,
mock_logger
):
"""Test error handling in some_method when dependencies raise exceptions."""
# Configure mocks to raise exceptions
mock_dependent_class1.some_method.side_effect = Exception("Error in DependentClass1")
mock_dependent_class2.another_method.side_effect = Exception("Error in DependentClass2")
# Inject mocked dependencies
lazy_loaded_class._dependent_class1 = mock_dependent_class1
lazy_loaded_class._dependent_class2 = mock_dependent_class2
lazy_loaded_class._logger = mock_logger
# Call the method under test
with pytest.raises(Exception) as exc_info:
lazy_loaded_class.some_method()
# Assertions
assert "Error in DependentClass1" in str(exc_info.value)
mock_logger.error.assert_called_with("An error occurred in some_method: Error in DependentClass1")
def test_repr(lazy_loaded_class):
"""Test the __repr__ method for correct string representation."""
expected_repr = "LazyLoadedClass(param1='example_value', param2=42)"
assert repr(lazy_loaded_class) == expected_repr
def test_str(lazy_loaded_class):
"""Test the __str__ method for correct string output."""
expected_str = "LazyLoadedClass with param1=example_value and param2=42"
assert str(lazy_loaded_class) == expected_str
if __name__ == "__main__":
pytest.main([__file__])