etl/test/test_expected.cpp

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

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

Copyright(c) 2022 John Wellbelove

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files(the "Software"), to deal
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******************************************************************************/

#include "unit_test_framework.h"

#include "etl/expected.h"
#include "etl/type_traits.h"

#include <string>
#include <variant>

namespace
{
  struct Value
  {
    std::string v;

    Value()
    {
    }

    Value(const std::string v_)
      : v(v_)
    {
    }

    operator std::string() const
    {
      return v;
    }
  };

  struct ValueM
  {
    ValueM()
    {
    }

    ValueM(const std::string& v_) 
      : v(v_)
    {
    }

    ValueM(ValueM&&) = default;
    ValueM& operator =(ValueM&&) = default;

    ValueM(const ValueM&) = delete;
    ValueM& operator =(const ValueM&) = delete;

    std::string v;
  };

  struct Error
  {
    std::string e;

    Error() = default;
    Error(const Error&) = default;
    Error& operator =(const Error&) = default;

    Error(const std::string e_)
      : e(e_)
    {
    }

    Error& operator =(const std::string e_)
    {
      e = e_;
    }

    operator std::string() const
    {
      return e;
    }
  };

  struct ErrorM
  {
    ErrorM()
    {
    }

    ErrorM(const std::string& e_)
      : e(e_)
    {
    }

    ErrorM(ErrorM&&) = default;
    ErrorM& operator =(ErrorM&&) = default;

    ErrorM(const ErrorM&) = delete;
    ErrorM& operator =(const ErrorM&) = delete;

    std::string e;
  };

  using Expected   = etl::expected<Value,  Error>;
  using ExpectedV  = etl::expected<void,   Error>;
  using ExpectedM  = etl::expected<ValueM, ErrorM>;
  using ExpectedVM = etl::expected<void,   ErrorM>;

  using Unexpected  = etl::unexpected<Error>;
  using UnexpectedV = etl::unexpected<Error>;
  using UnexpectedM = etl::unexpected<ErrorM>;
}

namespace
{
  SUITE(test_result)
  {
    //*************************************************************************
    TEST(test_default_constructor)
    {
      Expected expected;

      CHECK_TRUE(expected.has_value());
      CHECK_TRUE(bool(expected));
    }

    //*************************************************************************
    TEST(test_constructor_for_result_with_value)
    {
      Value    input = { "value 1" };
      Expected expected(input);

      Value output = expected.value();

      CHECK_TRUE(expected.has_value());
      CHECK_TRUE(bool(expected));
      CHECK_TRUE(output.v == input.v);
    }

    //*************************************************************************
    TEST(test_constructor_for_const_result_with_value)
    {
      Value          input = { "value 1" };
      const Expected expected(input);

      const Value& output = expected.value();

      CHECK_TRUE(expected.has_value());
      CHECK_TRUE(bool(expected));
      CHECK_TRUE(output.v == input.v);
    }

    //*************************************************************************
    TEST(test_constructor_for_moveable_result_with_value)
    {
      ValueM    input = { "value 1" };
      ExpectedM expected(etl::move(input));

      ValueM output = etl::move(expected.value());

      CHECK_TRUE(expected.has_value());
      CHECK_TRUE(bool(expected));
      CHECK_TRUE(output.v == std::string("value 1"));
    }

    //*************************************************************************
    TEST(test_constructor_for_result_with_error)
    {
      Error      input = { "error 1" };
      Unexpected unexpected(input);
      Expected   expected(unexpected);

      Error output = expected.error();

      CHECK_FALSE(expected.has_value());
      CHECK_FALSE(bool(expected));
      CHECK(output.e == input.e);
    }

    //*************************************************************************
    TEST(test_constructor_for_const_result_with_error)
    {
      const Error      input = { "error 1" };
      const Unexpected unexpected(input);
      const Expected   expected(unexpected);

      const Error& output = expected.error();

      CHECK_FALSE(expected.has_value());
      CHECK_FALSE(bool(expected));
      CHECK(output.e == input.e);
    }

    //*************************************************************************
    TEST(test_constructor_for_moveable_result_with_error)
    {
      ErrorM      input = { "error 1" };
      UnexpectedM unexpected(etl::move(input));
      ExpectedM   expected(etl::move(unexpected));

      ErrorM output = etl::move(expected.error());

      CHECK_FALSE(expected.has_value());
      CHECK_FALSE(bool(expected));
      CHECK_TRUE(output.e == std::string("error 1"));
    }

    //*************************************************************************
    TEST(test_constructor_for_result_void_value_with_value)
    {
       ExpectedV expected;

       CHECK_TRUE(expected.has_value());
       CHECK_TRUE(bool(expected));
    }

    //*************************************************************************
    TEST(test_constructor_for_const_result_void_value_with_value)
    {
       const ExpectedV expected;

       CHECK_TRUE(expected.has_value());
       CHECK_TRUE(bool(expected));
    }

    //*************************************************************************
    TEST(test_constructor_for_result_void_value_with_error)
    {
      Error       input = { "error 1" };
      UnexpectedV unexpected(input);
      ExpectedV   expected(unexpected);

      Error output = expected.error();

      CHECK_FALSE(expected.has_value());
      CHECK_FALSE(bool(expected));
      CHECK_TRUE(output.e == input.e);
    }

    //*************************************************************************
    TEST(test_constructor_for_const_result_void_value_with_error)
    {
      const Error       input = { "error 1" };
      const UnexpectedV unexpected(input);
      const ExpectedV   expected(unexpected);

      const Error& output = expected.error();

      CHECK_FALSE(expected.has_value());
      CHECK_FALSE(bool(expected));
      CHECK_TRUE(output.e == input.e);
    }

    //*************************************************************************
    TEST(test_constructor_for_moveable_result_void_value_with_error)
    {
      ErrorM      input = { "error 1" };
      UnexpectedM unexpected(etl::move(input));
      ExpectedM   expected(etl::move(unexpected));

      ErrorM output = etl::move(expected.error());

      CHECK_FALSE(expected.has_value());
      CHECK_FALSE(bool(expected));
      CHECK(output.e == std::string("error 1"));
    }

    //*************************************************************************
    TEST(test_copy_construct)
    {
      Value    input1 = { "value 1" };
      Expected expected1(input1);
      Expected expected2(expected1);

      Value output1 = expected2.value();

      CHECK_TRUE(expected1.has_value());
      CHECK_TRUE(expected2.has_value());
      CHECK(output1.v == input1.v);
    }

    //*************************************************************************
    TEST(test_copy_assign)
    {
      Value    input1 = { "value 1" };
      Expected expected1(input1);

      Value    input2 = { "value 2" };
      Expected expected2(input2);

      expected2 = expected1;

      Value output1 = expected1.value();
      Value output2 = expected2.value();

      CHECK_TRUE(expected1.has_value());
      CHECK_TRUE(expected2.has_value());

      //CHECK(output1.v != input1.v);
      //CHECK(output2.v != input1.v);

      //CHECK(output1.v == input2.v);
      //CHECK(output2.v == input2.v);
    }

    //*************************************************************************
    TEST(test_move_construct)
    {
      ValueM    input1 = { "value 1" };
      ExpectedM expected1(etl::move(input1));
      ExpectedM expected2(etl::move(expected1));

      ValueM output1 = etl::move(expected1.value());
      ValueM output2 = etl::move(expected2.value());

      CHECK_TRUE(expected1.has_value());
      CHECK_TRUE(expected2.has_value());

      CHECK_EQUAL("", output1.v);
      CHECK_EQUAL("value 1", output2.v);
    }

    //*************************************************************************
    TEST(test_move_assign)
    {
      ValueM    input1 = { "value 1" };
      ExpectedM expected1(etl::move(input1));

      ValueM    input2 = { "value 2" };
      ExpectedM expected2(etl::move(input2));

      expected2 = etl::move(expected1);

      ValueM output1 = etl::move(expected1.value());
      ValueM output2 = etl::move(expected2.value());

      CHECK_TRUE(expected1.has_value());
      CHECK_TRUE(expected2.has_value());

      CHECK_EQUAL("", output1.v);
      CHECK_EQUAL("value 1", output2.v);
    }

    //*************************************************************************
    TEST(test_copy_construct_void_value)
    {
      Error       input1 = { "error 1" };
      UnexpectedV unexpected1(input1);
      ExpectedV   expected1(unexpected1);
      ExpectedV   expected2(expected1);

      CHECK_FALSE(expected1.has_value());
      CHECK_FALSE(expected2.has_value());

      Error output1 = expected1.error();
      Error output2 = expected2.error();

      CHECK_EQUAL(input1.e, output1.e);
      CHECK_EQUAL(input1.e, output2.e);
    }

    //*************************************************************************
    TEST(test_copy_assign_void_value)
    {
      Error       input1 = { "error 1" };
      UnexpectedV unexpected1(input1);

      Error       input2 = { "error 2" };
      UnexpectedV unexpected2(input2);

      ExpectedV   expected1(unexpected1);
      ExpectedV   expected2(unexpected2);
      
      expected2 = expected1;

      Error output1 = expected1.error();
      Error output2 = expected2.error();

      CHECK_FALSE(expected1.has_value());
      CHECK_FALSE(expected2.has_value());

      CHECK_EQUAL(input1.e, output1.e);
      CHECK_EQUAL(input1.e, output2.e);
    }

    //*************************************************************************
    TEST(test_move_construct_void_value)
    {
      ErrorM      input1 = { "error 1" };
      UnexpectedM unexpected1(etl::move(input1));
      ExpectedVM  expected1(etl::move(unexpected1));
      ExpectedVM  expected2(etl::move(expected1));

      ErrorM output1 = etl::move(expected1.error());
      ErrorM output2 = etl::move(expected2.error());

      CHECK_FALSE(expected1.has_value());
      CHECK_FALSE(expected2.has_value());

      CHECK_EQUAL("",        output1.e);
      CHECK_EQUAL("error 1", output2.e);
    }

    //*************************************************************************
    TEST(test_move_assign_void_value)
    {
      ErrorM      input1 = { "error 1" };
      UnexpectedM unexpected1(etl::move(input1));

      ErrorM      input2 = { "error 2" };
      UnexpectedM unexpected2(etl::move(input2));

      ExpectedVM  expected1(etl::move(unexpected1));
      ExpectedVM  expected2(etl::move(unexpected2));

      expected2 = etl::move(expected1);

      ErrorM output1 = etl::move(expected1.error());
      ErrorM output2 = etl::move(expected2.error());

      CHECK_FALSE(expected1.has_value());
      CHECK_FALSE(expected2.has_value());

      CHECK_EQUAL("",        output1.e);
      CHECK_EQUAL("error 1", output2.e);
    }
  };
}