test.php

abstract class FooTest extends PHPUnit_Framework_Test
{
    // general setup shit
}

class Foo_BarTest extends FooTest
{
    /**
     * @test
     */
    public function it_shouldDoBar_whhn_qux
    {

    }
}

class Foo_BazTest extends FooTest
{
    /**
     * @test
     */
    public function it_shouldDoBaz_when_qux
    {

    }
}