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/*
* Copyright (c) 2021, Ali Mohammad Pur <mpfard@serenity.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <LibTest/TestSuite.h>
#include <AK/RefPtr.h>
#include <AK/Variant.h>
namespace {
struct Object : public RefCounted<Object> {
};
}
TEST_CASE(basic)
{
Variant<int, String> the_value { 42 };
EXPECT(the_value.has<int>());
EXPECT_EQ(the_value.get<int>(), 42);
the_value = String("42");
EXPECT(the_value.has<String>());
EXPECT_EQ(the_value.get<String>(), "42");
}
TEST_CASE(visit)
{
bool correct = false;
Variant<int, String, float> the_value { 42.0f };
the_value.visit(
[&](const int&) { correct = false; },
[&](const String&) { correct = false; },
[&](const float&) { correct = true; });
EXPECT(correct);
}
TEST_CASE(destructor)
{
struct DestructionChecker {
explicit DestructionChecker(bool& was_destroyed)
: m_was_destroyed(was_destroyed)
{
}
~DestructionChecker()
{
m_was_destroyed = true;
}
bool& m_was_destroyed;
};
bool was_destroyed = false;
{
Variant<DestructionChecker> test_variant { DestructionChecker { was_destroyed } };
}
EXPECT(was_destroyed);
bool was_destroyed_when_assigned_to = false;
Variant<DestructionChecker, int> original { DestructionChecker { was_destroyed_when_assigned_to } };
Variant<DestructionChecker, int> other { 42 };
original = other;
EXPECT(was_destroyed_when_assigned_to);
}
TEST_CASE(move_moves)
{
struct NoCopy {
AK_MAKE_NONCOPYABLE(NoCopy);
public:
NoCopy() = default;
NoCopy(NoCopy&&) = default;
};
Variant<NoCopy, int> first_variant { 42 };
// Should not fail to compile
first_variant = NoCopy {};
Variant<NoCopy, int> second_variant = move(first_variant);
EXPECT(second_variant.has<NoCopy>());
}
TEST_CASE(verify_cast)
{
Variant<i8, i16, i32, i64> one_integer_to_rule_them_all { static_cast<i32>(42) };
auto fake_integer = one_integer_to_rule_them_all.downcast<i8, i32>();
EXPECT(fake_integer.has<i32>());
EXPECT(one_integer_to_rule_them_all.has<i32>());
EXPECT_EQ(fake_integer.get<i32>(), 42);
EXPECT_EQ(one_integer_to_rule_them_all.get<i32>(), 42);
fake_integer = static_cast<i8>(60);
one_integer_to_rule_them_all = fake_integer.downcast<i8, i16>().downcast<i8, i32, float>().downcast<i8, i16, i32, i64>();
EXPECT(fake_integer.has<i8>());
EXPECT(one_integer_to_rule_them_all.has<i8>());
EXPECT_EQ(fake_integer.get<i8>(), 60);
EXPECT_EQ(one_integer_to_rule_them_all.get<i8>(), 60);
}
TEST_CASE(moved_from_state)
{
// Note: This test requires that Vector's moved-from state be consistent
// it need not be in a specific state (though as it is currently implemented,
// a moved-from vector is the same as a newly-created vector)
// This test does not make assumptions about the state itself, but rather that
// it remains consistent when done on different instances.
// Should this assumption be broken, we should probably switch to defining a local
// class that has fixed semantics, but I doubt the moved-from state of Vector will
// change any time soon :P
Vector<i32> bunch_of_values { 1, 2, 3, 4, 5, 6, 7, 8 };
Variant<Vector<i32>, Empty> optionally_a_bunch_of_values { Vector<i32> { 1, 2, 3, 4, 5, 6, 7, 8 } };
{
[[maybe_unused]] auto devnull_0 = move(bunch_of_values);
[[maybe_unused]] auto devnull_1 = move(optionally_a_bunch_of_values);
}
// The moved-from state should be the same in both cases, and the variant should still contain a moved-from vector.
// Note: Use after move is intentional.
EXPECT(optionally_a_bunch_of_values.has<Vector<i32>>());
auto same_contents = __builtin_memcmp(&bunch_of_values, &optionally_a_bunch_of_values.get<Vector<i32>>(), sizeof(bunch_of_values)) == 0;
EXPECT(same_contents);
}
TEST_CASE(duplicated_types)
{
Variant<int, int, int, int> its_just_an_int { 42 };
EXPECT(its_just_an_int.has<int>());
EXPECT_EQ(its_just_an_int.get<int>(), 42);
}
TEST_CASE(return_values)
{
using MyVariant = Variant<int, String, float>;
{
MyVariant the_value { 42.0f };
float value = the_value.visit(
[&](const int&) { return 1.0f; },
[&](const String&) { return 2.0f; },
[&](const float& f) { return f; });
EXPECT_EQ(value, 42.0f);
}
{
MyVariant the_value { 42 };
int value = the_value.visit(
[&](int& i) { return i; },
[&](String&) { return 2; },
[&](float&) { return 3; });
EXPECT_EQ(value, 42);
}
{
const MyVariant the_value { "str" };
String value = the_value.visit(
[&](const int&) { return String { "wrong" }; },
[&](const String& s) { return s; },
[&](const float&) { return String { "wrong" }; });
EXPECT_EQ(value, "str");
}
}
TEST_CASE(return_values_by_reference)
{
auto ref = adopt_ref_if_nonnull(new (nothrow) Object());
Variant<int, String, float> the_value { 42.0f };
auto& value = the_value.visit(
[&](const int&) -> RefPtr<Object>& { return ref; },
[&](const String&) -> RefPtr<Object>& { return ref; },
[&](const float&) -> RefPtr<Object>& { return ref; });
EXPECT_EQ(ref, value);
EXPECT_EQ(ref->ref_count(), 1u);
EXPECT_EQ(value->ref_count(), 1u);
}
struct HoldsInt {
int i;
};
struct HoldsFloat {
float f;
};
TEST_CASE(copy_assign)
{
{
Variant<int, String, float> the_value { 42.0f };
VERIFY(the_value.has<float>());
EXPECT_EQ(the_value.get<float>(), 42.0f);
int twelve = 12;
the_value = twelve;
VERIFY(the_value.has<int>());
EXPECT_EQ(the_value.get<int>(), 12);
the_value = String("Hello, world!");
VERIFY(the_value.has<String>());
EXPECT_EQ(the_value.get<String>(), "Hello, world!");
}
{
Variant<HoldsInt, String, HoldsFloat> the_value { HoldsFloat { 42.0f } };
VERIFY(the_value.has<HoldsFloat>());
EXPECT_EQ(the_value.get<HoldsFloat>().f, 42.0f);
HoldsInt twelve { 12 };
the_value = twelve;
VERIFY(the_value.has<HoldsInt>());
EXPECT_EQ(the_value.get<HoldsInt>().i, 12);
the_value = String("Hello, world!");
VERIFY(the_value.has<String>());
EXPECT_EQ(the_value.get<String>(), "Hello, world!");
}
}
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