etl/test/test_delegate_observable.cpp

/******************************************************************************
The MIT License(MIT)

Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com

Copyright(c) 2025 John Wellbelove

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#include "unit_test_framework.h"

#include "etl/delegate.h"
#include "etl/delegate_observable.h"

#if !defined(ETL_DELEGATE_FORCE_CPP03_IMPLEMENTATION)

namespace
{
  const size_t Max_Observers = 2UL;

  using Notification = int;
  using Observable   = etl::delegate_observable<Notification, Max_Observers>;
  using Delegate     = Observable::delegate_type;

  //*****************************************************************************
  bool global_called = false;
  bool member_called = false;
  int  global_value  = 0;
  int  member_value  = 0;

  //*****************************************************************************
  // The global function taking no parameters.
  //*****************************************************************************
  static void global(int id)
  {
    global_called = true;
    global_value  = id;
  }

  //*****************************************************************************
  // The test class with member functions.
  //*****************************************************************************
  class Object
  {
  public:

    ETL_CONSTEXPR14 Object() {}

    void member(int id)
    {
      member_called = true;
      member_value  = id;
    }
  };

  Object object;

  // Callback for 'member1'.
  ETL_CONSTEXPR14 Delegate member_callback = Delegate::create<Object, &Object::member, object>();

  // Callback for 'global1'.
  ETL_CONSTEXPR14 Delegate global_callback = Delegate::create<global>();

  //*****************************************************************************
  // Initialises the test results.
  //*****************************************************************************
  struct SetupFixture
  {
    SetupFixture()
    {
      global_called = false;
      member_called = false;
      global_value  = 0;
      member_value  = 0;
    }
  };

  #if defined(ETL_COMPILER_GCC)
    #if (ETL_COMPILER_FULL_VERSION <= 1100)
      #define ETL_GCC_11 1
    #else
      #define ETL_GCC_11 0
    #endif
  #else
    #define ETL_GCC_11 0
  #endif

  #define ETL_ENABLE_DELEGATE_OBSERVABLE_CREATE_OBSERVABLE (ETL_GCC_11 && ETL_USING_CPP14)

  #if ETL_ENABLE_DELEGATE_OBSERVABLE_CREATE_OBSERVABLE
  //*************************************************************************
  ETL_CONSTEXPR14 Observable CreateObservable()
  {
    Observable observable;

    observable.add_observer(global_callback);
    observable.add_observer(member_callback);

    observable.remove_observer(global_callback);

    return observable;
  }
  #endif
} // namespace

namespace
{
  SUITE(test_delegate_service)
  {
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_constexpr_delegate_observable)
    {
      static ETL_CONSTEXPR14 Observable observable(global_callback, member_callback);

      CHECK_EQUAL(2, observable.number_of_observers());

      observable.notify_observers(1);

      CHECK_TRUE(global_called);
      CHECK_TRUE(member_called);
      CHECK_EQUAL(1, global_value);
      CHECK_EQUAL(1, member_value);

      //*********************************
      global_called = false;
      member_called = false;

      observable.notify_observers(2);

      CHECK_TRUE(global_called);
      CHECK_TRUE(member_called);
      CHECK_EQUAL(2, global_value);
      CHECK_EQUAL(2, member_value);
    }

  #if ETL_USING_CPP17
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_constexpr_delegate_observable_using_template_deduction_guide_cpp17)
    {
      static ETL_CONSTEXPR14 etl::delegate_observable observable(int{}, global_callback, member_callback);

      CHECK_EQUAL(2, observable.number_of_observers());

      observable.notify_observers(1);

      CHECK_TRUE(global_called);
      CHECK_TRUE(member_called);
      CHECK_EQUAL(1, global_value);
      CHECK_EQUAL(1, member_value);

      //*********************************
      global_called = false;
      member_called = false;

      observable.notify_observers(2);

      CHECK_TRUE(global_called);
      CHECK_TRUE(member_called);
      CHECK_EQUAL(2, global_value);
      CHECK_EQUAL(2, member_value);
    }
  #endif

  #if ETL_ENABLE_DELEGATE_OBSERVABLE_CREATE_OBSERVABLE
    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_constexpr_delegate_observable_from_function)
    {
      static ETL_CONSTEXPR14 Observable observable = CreateObservable();

      CHECK_EQUAL(1, observable.number_of_observers());

      observable.notify_observers(1);

      CHECK_FALSE(global_called);
      CHECK_TRUE(member_called);
      CHECK_EQUAL(0, global_value);
      CHECK_EQUAL(1, member_value);

      //*********************************
      global_called = false;
      member_called = false;

      observable.notify_observers(2);

      CHECK_FALSE(global_called);
      CHECK_TRUE(member_called);
      CHECK_EQUAL(0, global_value);
      CHECK_EQUAL(2, member_value);
    }
  #endif

    //*************************************************************************
    TEST_FIXTURE(SetupFixture, test_delegate_observable_add_and_remove)
    {
      Observable observable;
      CHECK_EQUAL(0, observable.number_of_observers());

      observable.notify_observers(1);
      CHECK_FALSE(global_called);
      CHECK_FALSE(member_called);
      CHECK_EQUAL(0, global_value);
      CHECK_EQUAL(0, member_value);

      //*********************************
      global_called = false;
      member_called = false;

      observable.add_observer(global_callback);
      CHECK_EQUAL(1, observable.number_of_observers());

      observable.notify_observers(2);
      CHECK_TRUE(global_called);
      CHECK_FALSE(member_called);
      CHECK_EQUAL(2, global_value);
      CHECK_EQUAL(0, member_value);

      //*********************************
      global_called = false;
      member_called = false;

      observable.add_observer(member_callback);
      CHECK_EQUAL(2, observable.number_of_observers());

      observable.notify_observers(3);
      CHECK_TRUE(global_called);
      CHECK_TRUE(member_called);
      CHECK_EQUAL(3, global_value);
      CHECK_EQUAL(3, member_value);

      //*********************************
      global_called = false;
      member_called = false;

      observable.remove_observer(global_callback);
      CHECK_EQUAL(1, observable.number_of_observers());

      observable.notify_observers(4);
      CHECK_FALSE(global_called);
      CHECK_TRUE(member_called);
      CHECK_EQUAL(3, global_value);
      CHECK_EQUAL(4, member_value);

      //*********************************
      global_called = false;
      member_called = false;

      observable.clear_observers();
      CHECK_EQUAL(0, observable.number_of_observers());

      observable.notify_observers(5);
      CHECK_FALSE(global_called);
      CHECK_FALSE(member_called);
      CHECK_EQUAL(3, global_value);
      CHECK_EQUAL(4, member_value);
    }
  }
} // namespace

#endif