"""Tests for PolynomialRegression class."""

import pytest


class TestPolynomialRegression:
    """Test cases for PolynomialRegression class."""

    @pytest.fixture
    def sample_data(self):
        """Create sample polynomial data for testing."""
        # TODO: Create sample polynomial datasets
        pass

    @pytest.fixture
    def model(self):
        """Create a PolynomialRegression model instance."""
        # TODO: Create model instance
        pass

    def test_initialization(self):
        """Test model initialization."""
        # TODO: Test initialization with different degrees
        pass

    def test_polynomial_features(self, model):
        """Test polynomial feature creation."""
        # TODO: Test polynomial feature transformation
        pass

    def test_fit(self, model, sample_data):
        """Test fitting polynomial regression."""
        # TODO: Test fitting on polynomial data
        pass

    def test_predict(self, model, sample_data):
        """Test prediction functionality."""
        # TODO: Test predictions
        pass

    def test_score(self, model, sample_data):
        """Test R² score calculation."""
        # TODO: Test R² score
        pass

    def test_quadratic_regression(self):
        """Test quadratic regression (degree=2)."""
        # TODO: Test on y = ax² + bx + c type data
        pass

    def test_cubic_regression(self):
        """Test cubic regression (degree=3)."""
        # TODO: Test on cubic polynomial data
        pass

    def test_overfitting_high_degree(self):
        """Test behavior with high polynomial degrees."""
        # TODO: Test overfitting scenarios
        pass

    def test_edge_cases(self):
        """Test edge cases and error handling."""
        # TODO: Test edge cases
        pass
