/** * popAtomic should not call the callback if there are no messages */ public function testPopAtomicEmpty() { $did_run = false; $callback = function ($unused) use(&$did_run) { $did_run = true; }; $data = $this->object->popAtomic($callback); $this->assertNull($data, 'Should return null on an empty queue'); $this->assertFalse($did_run, 'Should not call callback without a message'); }