text: /** @file
  
      IntrusivePtr tests.
  
      @section license License
  
      Licensed to the Apache Software Foundation (ASF) under one
      or more contributor license agreements.  See the NOTICE file
      distributed with this work for additional information
      regarding copyright ownership.  The ASF licenses this file
      to you under the Apache License, Version 2.0 (the
      "License"); you may not use this file except in compliance
      with the License.  You may obtain a copy of the License at
  
      http://www.apache.org/licenses/LICENSE-2.0
  
      Unless required by applicable law or agreed to in writing, software
      distributed under the License is distributed on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
      See the License for the specific language governing permissions and
      limitations under the License.
  */
  
  #include <string>
  #include <sstream>
  #include <tsconfig/IntrusivePtr.h>
  #include <catch.hpp>
  
  struct Thing : public ts::IntrusivePtrCounter {
    Thing() { ++_count; }
    virtual ~Thing() { --_count; }
    std::string _name;
    static int _count; // instance count.
  };
  
  struct Stuff : public Thing {
    int _value{0};
  };
  
  struct Obscure : private ts::IntrusivePtrCounter {
    std::string _text;
  
    friend class ts::IntrusivePtr<Obscure>;
  };
  
  struct Item : public ts::IntrusivePtrCounter {
    ts::IntrusivePtr<Item> _next;
    Item() { ++_count; }
    ~Item() { --_count; }
    static int _count; // instance count.
  };
  
  struct Atomic : ts::IntrusivePtrAtomicCounter {
    int _q{0};
  };
  
  int Thing::_count{0};
  int Item::_count{0};
  
  TEST_CASE("IntrusivePtr", "[libts][IntrusivePtr]")
  {
    using Ptr = ts::IntrusivePtr<Thing>;
  
    Ptr p1{new Thing};
    REQUIRE(p1.use_count() == 1);
    REQUIRE(Thing::_count == 1);
    p1.reset(nullptr);
    REQUIRE(Thing::_count == 0);
  
    p1.reset(new Thing);
    Ptr p2 = p1;
    REQUIRE(Thing::_count == 1);
    REQUIRE(p1.use_count() == p2.use_count());
    REQUIRE(p2.use_count() == 2);
  
    Ptr p3{new Thing};
    REQUIRE(Thing::_count == 2);
    p1 = p3;
    p2 = p3;
    REQUIRE(Thing::_count == 1);
  
    Ptr p4;
  
    REQUIRE(static_cast<bool>(p4) == false);
    REQUIRE(!p4 == true);
  
    REQUIRE(static_cast<bool>(p3) == true);
    REQUIRE(!p3 == false);
  
    // This is a compile check to make sure IntrusivePtr can be used with private inheritance
    // of ts::InstrusivePtrCounter if IntrusivePtr is declared a friend.
    ts::IntrusivePtr<Obscure> op{new Obscure};
    op->_text.assign("Text");
  }
  
  // List test.
  TEST_CASE("IntrusivePtr List", "[libts][IntrusivePtr]")
  {
    // The clang analyzer claims this type of list manipulation leads to use after free because of
    // premature class destruction but these tests verify that is a false positive.
  
    using LP = ts::IntrusivePtr<Item>;
  
    LP list{new Item}; // start a list
    {
      // Add an item to the front of the list.
      LP item{new Item};
  
      REQUIRE(Item::_count == 2);
      REQUIRE(list.use_count() == 1);
      REQUIRE(item.use_count() == 1);
      item->_next = list;
      REQUIRE(Item::_count == 2);
      REQUIRE(list.use_count() == 2);
      REQUIRE(item.use_count() == 1);
      list = item;
      REQUIRE(Item::_count == 2);
      REQUIRE(list.use_count() == 2);
    }
    REQUIRE(Item::_count == 2);
    REQUIRE(list.use_count() == 1);
    REQUIRE(list->_next.use_count() == 1);
  
    {
      // add an item after the first element in a non-empty list.
      LP item{new Item};
  
      REQUIRE(Item::_count == 3);
      REQUIRE(list.use_count() == 1);
      REQUIRE(item.use_count() == 1);
      item->_next = list->_next;
      REQUIRE(Item::_count == 3);
      REQUIRE(list.use_count() == 1);
      REQUIRE(item.use_count() == 1);
      REQUIRE(item->_next.use_count() == 2);
      list->_next = item;
      REQUIRE(Item::_count == 3);
      REQUIRE(item.use_count() == 2);
      REQUIRE(list->_next.get() == item.get());
      REQUIRE(item->_next.use_count() == 1);
    }
    REQUIRE(Item::_count == 3);
    REQUIRE(list.use_count() == 1);
    REQUIRE(list->_next.use_count() == 1);
    list.reset();
    REQUIRE(Item::_count == 0);
  
    list.reset(new Item); // start a list
    REQUIRE(Item::_count == 1);
    {
      // Add item after first in singleton list.
      LP item{new Item};
      REQUIRE(Item::_count == 2);
      REQUIRE(list.use_count() == 1);
      REQUIRE(item.use_count() == 1);
      REQUIRE(!list->_next);
      item->_next = list->_next;
      REQUIRE(!item->_next);
      REQUIRE(Item::_count == 2);
      REQUIRE(list.use_count() == 1);
      REQUIRE(item.use_count() == 1);
      list->_next = item;
      REQUIRE(Item::_count == 2);
      REQUIRE(item.use_count() == 2);
      REQUIRE(list->_next.get() == item.get());
    }
    REQUIRE(Item::_count == 2);
    REQUIRE(list.use_count() == 1);
    REQUIRE(list->_next.use_count() == 1);
    list.reset();
    REQUIRE(Item::_count == 0);
  }
  
  // Cross type tests.
  TEST_CASE("IntrusivePtr CrossType", "[libts][IntrusivePtr]")
  {
    using ThingPtr = ts::IntrusivePtr<Thing>;
    using StuffPtr = ts::IntrusivePtr<Stuff>;
  
    ThingPtr tp1{new Stuff};
    StuffPtr sp1{new Stuff};
  
    ThingPtr tp2{sp1};
    REQUIRE(tp2.get() == sp1.get());
    REQUIRE(Thing::_count == 2);
    REQUIRE(tp2.use_count() == 2);
    tp2 = sp1; // should be a no-op, verify it compiles.
    REQUIRE(tp2.get() == sp1.get());
    REQUIRE(Thing::_count == 2);
    REQUIRE(sp1.use_count() == 2);
    sp1 = ts::ptr_cast<Stuff>(tp1); // move assign
    REQUIRE(sp1.get() == tp1.get());
    REQUIRE(sp1.use_count() == 2);
    REQUIRE(tp2.use_count() == 1);
    tp1 = ts::ptr_cast<Stuff>(tp2); // cross type move assign
    REQUIRE(sp1.use_count() == 1);
    REQUIRE(tp1.get() == tp2.get());
    REQUIRE(tp1.use_count() == 2);
    sp1 = ts::ptr_cast<Stuff>(tp1);
    REQUIRE(Thing::_count == 1);
    REQUIRE(sp1.use_count() == 3);
    tp1 = tp2; // same object assign check.
    {
      StuffPtr sp2{sp1};
      REQUIRE(sp1.use_count() == 4);
    }
    sp1.reset();
    tp1 = std::move(tp2); // should clear tp2
    tp1.reset();
    REQUIRE(Thing::_count == 0);
  }
  
  TEST_CASE("IntrusiveAtomicPtr", "[libts][IntrusivePtr]")
  {
    using Ptr = ts::IntrusivePtr<Atomic>;
  
    Ptr p1{new Atomic};
    REQUIRE(p1.use_count() == 1);
    p1.reset(nullptr);
  }
  