LUMIERA.clone/tests/basics/dependency-factory-test.cpp

/*
  DependencyFactory(Test)  -  verify modes of creating singletons and dependencies

  Copyright (C)         Lumiera.org
    2013,               Hermann Vosseler <Ichthyostega@web.de>

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License as
  published by the Free Software Foundation; either version 2 of
  the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

* *****************************************************/

/** @file dependency-factory-test.cpp
 ** unit test \ref DependencyFactory_test
 ** @remark this is an old test from 2013 and thus verifies that the functionality
 **         for dependency-injection was not broken by the rewrite in 2018
 ** @see dependency-configuration-test.cpp
 */



#include "lib/test/run.hpp"
#include "lib/format-obj.hpp"
#include "lib/util.hpp"

#include "lib/depend.hpp"
#include "lib/depend-inject.hpp"
#include "test-target-obj.hpp"

#include <cstdlib>



namespace lib {
namespace test{
  
  using ::Test;
  using util::isSameObject;
  
  namespace {
    
    const uint MAX_ID = 1000;
    
    struct Sub
      : TestTargetObj
      {
        static uint created;
        uint instanceID_;
        
        Sub()
          : TestTargetObj(created++)
          ,instanceID_(rand() % MAX_ID)
          { }
        
        virtual operator string()  const
          {
            return util::typeStr(this)
                 + TestTargetObj::operator string();
          }
      };
    uint Sub::created = 0;
    
    
    struct SubSub
      : Sub
      { };
    
    struct SubSubSub
      : SubSub
      { };
    
    struct SubSubDub
      : SubSub
      { };
  }
  
  
  
  
  
  /***************************************************************************//**
   * @test verify the various modes of creating dependencies.
   *       - standard case is singleton creation
   *       - configuration of a specific subclass for the singleton
   *       - use of a custom factory function
   *       - injection of a mock implementation for unit tests
   * 
   * @see lib::Dependency
   * @see Singleton_test
   * @see DependencyConfiguration_test newer test from 2018 to cover the same ground
   */
  class DependencyFactory_test : public Test
    {
      
      
      virtual void
      run (Arg)
        {
          verify_defaultSingletonCreation();
          verify_SubclassCreation();
          verify_FactoryDefinition_is_sticky();
          verify_customFactory();
          verify_automaticReplacement();
        }
      
      
      void
      verify_defaultSingletonCreation()
        {
          Depend<Sub> accessor1;
          Depend<Sub> accessor2;
          
          Sub & o1 = accessor1();
          Sub & o2 = accessor2();
          CHECK (isSameObject (o1, o2));
        }
      
      
      void
      verify_SubclassCreation()
        {
          Depend<SubSub> specialAccessor;
          Depend<Sub>    genericAccessor;
          
          // configure singleton subclass (prior to first use)
          DependInject<SubSub>::useSingleton<SubSubSub>();
          
          SubSub& oSub = specialAccessor();
          Sub&    o    = genericAccessor();
          
          CHECK (!isSameObject (oSub, o));
          CHECK ( INSTANCEOF (SubSubSub, &oSub));
          CHECK (!INSTANCEOF (SubSubSub, &o));
        }
      
      
      void
      verify_FactoryDefinition_is_sticky()
        {
          Depend<SubSub> otherSpecialAccessor;
          
          SubSub& oSub = otherSpecialAccessor();
          CHECK ( INSTANCEOF (SubSubSub, &oSub));
          
          Depend<SubSubSub> yetAnotherSpecialAccessor;
          
          SubSub& yetAnotherInstance = yetAnotherSpecialAccessor();
          CHECK ( INSTANCEOF (SubSubSub, &yetAnotherInstance));
          
          // both refer to the same configuration and thus access the singleton
          CHECK (isSameObject (oSub, yetAnotherInstance));
        }
      
      
      void
      verify_customFactory()
        {
          DependInject<SubSubDub>::useSingleton (customFactoryFunction);
          
          Depend<SubSubDub> customised;
          
          CHECK ( INSTANCEOF (SubSubDub, &customised()));
          CHECK (MAX_ID + 10      == customised().instanceID_);
        }
      
      static SubSubDub*
      customFactoryFunction (void)
        {
          SubSubDub* specialInstance = new SubSubDub;
          specialInstance->instanceID_ = MAX_ID + 10;
          return specialInstance;
        }
      
      
      
      void
      verify_automaticReplacement()
        {
          Depend<Sub> genericAccessor;
          Sub& original = genericAccessor();
          uint oID = original.instanceID_;
          
          {////////////////////////////////////////////////////TEST-Scope
            DependInject<Sub>::Local<SubSubSub> mockObject;
            
            Sub& replacement = genericAccessor();
            CHECK ( isSameObject (replacement, *mockObject));
            CHECK (!isSameObject (original, replacement));
            
            Depend<SubSub>   special;
            Depend<SubSubSub> custom;
            
            CHECK(!isSameObject (replacement, special() ));
            CHECK(!isSameObject (replacement, custom()  ));
          }////////////////////////////////////////////////////(End)TEST-Scope
          
          Sub& nextFetch = genericAccessor();
          CHECK (isSameObject (original, nextFetch));
          CHECK (oID == nextFetch.instanceID_);
          
          {////////////////////////////////////////////////////TEST-Scope-2
            DependInject<Sub>::Local<SubSub> otherMock;
            
            Sub& replacement = genericAccessor();
            uint repID = replacement.instanceID_;
            
            CHECK (!INSTANCEOF (SubSub, &original));
            CHECK ( INSTANCEOF (SubSub, &replacement));
            CHECK (!INSTANCEOF (SubSubSub, &replacement));
            CHECK (!isSameObject (original, replacement));
            
            Depend<Sub> anotherAccessor;
            Sub& otherAccess = anotherAccessor();
            CHECK (isSameObject (replacement, otherAccess));
            CHECK (repID == otherAccess.instanceID_);
            CHECK (repID == replacement.instanceID_);
            CHECK (  oID == original.instanceID_);
            
             // verify the instrumentation indeed targeted the generic accessor,
            //  and *not* an accessor of the sub type, i.e Depend<SubSub>
            Depend<SubSub> genericSubTypeAccessor;
            SubSub& subTypeAccess = genericSubTypeAccessor();
            CHECK ( INSTANCEOF (SubSub, &subTypeAccess));
            CHECK (!isSameObject (replacement, subTypeAccess));
            CHECK (!isSameObject (original,    subTypeAccess));
            CHECK (repID != subTypeAccess.instanceID_);
            CHECK (  oID != subTypeAccess.instanceID_);
          }////////////////////////////////////////////////////(End)TEST-Scope-2
          
          CHECK (isSameObject (original, genericAccessor()));
          CHECK (oID == genericAccessor().instanceID_);
        }
    };
  
  
  
  LAUNCHER (DependencyFactory_test, "unit common");
  
  
}} // namespace lib::test