PHP フレームワークにおけるテスト駆動開発戦略

use PHPUnit\Framework\TestCase;

class ExampleTest extends TestCase
{
    public function testExample()
    {
        $result = calculateSum(1, 2);
        $this->assertEquals(3, $result);
    }
}

function calculateSum($a, $b)
{
    return $a + $b;
}

$ phpunit --filter ExampleTest

function sumNumbers(array $numbers)
{
    $sum = 0;
    foreach ($numbers as $number) {
        $sum += $number;
    }
    return $sum;
}

use PHPUnit\Framework\TestCase;

class SumNumbersTest extends TestCase
{
    public function testSumEmptyArray()
    {
        $result = sumNumbers([]);
        $this->assertEquals(0, $result);
    }

    public function testSumPositiveNumbers()
    {
        $result = sumNumbers([1, 2, 3]);
        $this->assertEquals(6, $result);
    }

    public function testSumNegativeNumbers()
    {
        $result = sumNumbers([-1, -2, -3]);
        $this->assertEquals(-6, $result);
    }

    public function testSumMixedNumbers()
    {
        $result = sumNumbers([1, -2, 3]);
        $this->assertEquals(2, $result);
    }
}