speed(50); self::$functions->shouldReceive('usleep') ->once() ->with(100000); $sleeper->sleep(); } /** @test */ public function it_can_speed_up_the_sleeper_speed() { $sleeper = new Sleeper; $sleeper->speed(200); self::$functions->shouldReceive('usleep') ->once() ->with(25000); $sleeper->sleep(); } /** @test */ public function it_will_ignore_zero_percentages() { $sleeper = new Sleeper; $sleeper->speed(0); self::$functions->shouldReceive('usleep') ->once() ->with(50000); $sleeper->sleep(); } }