PHP 単体テスト: テスト カバレッジのベスト プラクティス

<phpunit backupGlobals="false"
         backupStaticAttributes="false"
         bootstrap="vendor/autoload.php"
         colors="true"
         verbose="true"
         coverageClover="coverage.clover">
</phpunit>

public function dataProvider() {
    return [
        ['input' => 1, 'expected' => 2],
        ['input' => 2, 'expected' => 4]
    ];
}

/**
 * @dataProvider dataProvider
 */
public function testSum(int $input, int $expected) {
    $this->assertEquals($expected, $this->sum($input));
}

$calculatorMock = $this->createMock(Calculator::class);
$calculatorMock->expects($this->once())
    ->method('sum')
    ->with(1, 2)
    ->will($this->returnValue(3));

$this->assertEquals(3, $calculator->sum(1, 2));

<?php
class Calculator {
    public function sum(int $a, int $b) {
        if ($a < 0 || $b < 0) {
            throw new InvalidArgumentException('Input should be non-negative.');
        }
        return $a + $b;
    }
}

<?php
use PHPUnit\Framework\TestCase;

class CalculatorTest extends TestCase {
    public function dataProvider() {
        return [
            [-1, 2, 'InvalidArgumentException'],
            [1, -2, 'InvalidArgumentException'],
            [1, 2, 3]
        ];
    }

    /**
     * @dataProvider dataProvider
     */
    public function testSum(int $a, int $b, $expected) {
        $calculator = new Calculator();

        if (is_a($expected, 'InvalidArgumentException')) {
            $this->expectException($expected);
        }
        $this->assertEquals($expected, $calculator->sum($a, $b));
    }
}