Under-the-hood functions and methods in PHPUnit

1. Using Data Providers for Elegant Test Cases

I’ll provide a real-life example that already exists in the Laravel framework.

The #[DataProvider] attribute allows the same test logic to run with different inputs, ensuring thorough coverage.

The Test Case: Simplifying with a Data Provider

    #[DataProvider('greetingChoiceDataProvider')]
    public function testItCanHandleChoiceWithChoiceSeparatorInReplaceString(int $count, string $expected, ?string $locale = null)
    {
        if (!is_null($locale)) {
            $this->app->setLocale($locale);
        }

        $name = 'Taylor | Laravel';

        $this->assertSame(
            strtr($expected, [':name' => $name, ':count' => $count]),
            $this->app['translator']->choice('tests::app.greeting', $count, ['name' => $name])
        );
    }

public static function greetingChoiceDataProvider()
{
    yield [0, 'Hello :name'];
    yield [3, 'Hello :name, you have 3 unread messages'];
    yield [0, 'Bonjour :name', 'fr'];
    yield [3, 'Bonjour :name, vous avez :count messages non lus', 'fr'];
}

• Each yield defines a test scenario with input values ($count, $expected, and $locale).
• This ensures every edge case is tested without duplicating test logic.

I will add under-the-hood functions gradually, day by day. .... by