<?php

class Calculator
{
 public static function add($a, $b)
 {
  return $a + $b;
 }

 public static function divide($a, $b)
 {
  return $a / $b;
 }
}

use PHPUnit\Framework\TestCase;

class CalculatorTest extends TestCase
{
    public function testAddition(): void
    {
        // Positive Test Case 1: add() method
        $a = 5;
        $b = 10;
        $expectedSum = 15;
        $sum = Calculator::add($a, $b);
        $this->assertEquals($expectedSum, $sum);
    }

    public function testDivision(): void
    {
        // Positive Test Case 2: divide() method
        $a = 20;
        $b = 4;
        $expectedQuotient = 5;
        $quotient = Calculator::divide($a, $b);
        $this->assertEquals($expectedQuotient, $quotient);
    }

    public function testAdditionWithInvalidInput(): void
    {
        // Negative Test Case 1: add() method with invalid input
        $a = "abc";
        $b = 10;
        $this->expectException(TypeError::class);
        Calculator::add($a, $b);
    }

    public function testDivisionByZero(): void
    {
        // Negative Test Case 2: divide() method with division by zero
        $a = 10;
        $b = 0;
        $this->expectException(DivisionByZeroError::class);
        Calculator::divide($a, $b);
    }
}