DefaultMyStuffMaker.php

<?php

class DefaultMyStuffMaker implements MyStuffMaker
{
    private $dependency;
  
    public function __construct(SomeDependency $dependency)
    {
        $this->dependency = $dependency;
    }

    public function makeStuff(string $someArg) : SomeResult
    {
        // do some stuff
    }
}

DefaultMyStuffMakerSpec.php

<?php

class DefaultMyStuffMakerSpec extends ObjectSpec
{
  public function let(SomeDependency $dependency)
  {
    $this->beConstructedWith($dependecy);
  }
  
  public function it_makes_stuff()
  {
    $this->makeStuff()->shouldReturnAnInstanceOf(SomeResult::class)
  }
}

LoggableMyStuffMaker.php

<?php

class LoggableMyStuffMaker implements MyStuffMaker
{
    private $next;
    private $logger;
    
    public function __construct(MyStuffMaker $maker, Logger $logger) 
    {
        $this->next = $next;
        $this->logger = $logger;
    }
    
    public function makeStuff(string $someArg) : SomeResult
    {
        $this->logger->log("Maker called")
        $result = $this->next->makeStuff($someArg);
        $this->logger->log("Maker return result");
        
        return $result;
    }
}

LoggableMyStuffMakerSpec.php

<?php

class DefaultMyStuffMakerSpec extends ObjectSpec
{
  public function let(MyStuffMaker $maker, Logger $logger)
  {
    $this->beConstructedWith($maker, $logger);
  }
  
  public function it_makes_stuff(MyStuffMaker $maker, Logger $logger)
  {
    $maker->makeStuff('stuff')->shouldBeCalled()->willReturn(new SomeResult());
    $logger->log(Argument::type('string'))->shouldBeCalledTimes(2);
    
    $this->makeStuff('stuff');
  }
}

MyStuffMaker.php

<?php

interface MyStuffMaker
{
    public function makeStuff(string $someArg) : SomeResult
}