"""Tests for the calculator module."""

import pytest
from test_package.calculator import Calculator


class TestCalculator:
    """Test cases for Calculator class."""
    
    def setup_method(self):
        """Set up test fixtures."""
        self.calc = Calculator()
    
    def test_add(self):
        """Test addition operation."""
        assert self.calc.add(2, 3) == 5
        assert self.calc.add(-1, 1) == 0
        assert self.calc.add(0.1, 0.2) == pytest.approx(0.3)
    
    def test_subtract(self):
        """Test subtraction operation."""
        assert self.calc.subtract(5, 3) == 2
        assert self.calc.subtract(1, 1) == 0
        assert self.calc.subtract(-1, -2) == 1
    
    def test_multiply(self):
        """Test multiplication operation."""
        assert self.calc.multiply(3, 4) == 12
        assert self.calc.multiply(-2, 3) == -6
        assert self.calc.multiply(0, 100) == 0
    
    def test_divide(self):
        """Test division operation."""
        assert self.calc.divide(10, 2) == 5.0
        assert self.calc.divide(7, 2) == 3.5
        assert self.calc.divide(-6, 3) == -2.0
    
    def test_divide_by_zero(self):
        """Test division by zero raises error."""
        with pytest.raises(ValueError, match="Cannot divide by zero"):
            self.calc.divide(5, 0)
    
    def test_power(self):
        """Test power operation."""
        assert self.calc.power(2, 3) == 8
        assert self.calc.power(5, 0) == 1
        assert self.calc.power(2, -1) == 0.5