sol2/tests/runtime_tests/source/customizations.cpp

// sol3

// The MIT License (MIT)

// Copyright (c) 2013-2018 Rapptz, ThePhD and contributors

// Permission is hereby granted, free of charge, to any person obtaining a copy of
// this software and associated documentation files (the "Software"), to deal in
// the Software without restriction, including without limitation the rights to
// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
// the Software, and to permit persons to whom the Software is furnished to do so,
// subject to the following conditions:

// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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#include "sol_test.hpp"

#include <catch.hpp>

#include <unordered_map>
#include <vector>

struct two_things {
	int a;
	bool b;
};

struct number_shim {
	double num = 0;
};

namespace sol {

	// First, the expected size
	// Specialization of a struct
	template <>
	struct lua_size<two_things> : std::integral_constant<int, 2> {};

	// Then, the expected type
	template <>
	struct lua_type_of<two_things> : std::integral_constant<sol::type, sol::type::poly> {};

	// do note specialize size for this because it is our type
	template <>
	struct lua_type_of<number_shim> : std::integral_constant<sol::type, sol::type::poly> {};

	// Now, specialize various stack structures
	namespace stack {

		template <>
		struct checker<two_things> {
			template <typename Handler>
			static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
				// Check first and second second index for being the proper types
				bool success = stack::check<int>(L, index, handler) && stack::check<bool>(L, index + 1, handler);
				tracking.use(2);
				return success;
			}
		};

		template <>
		struct unqualified_getter<two_things> {
			static two_things get(lua_State* L, int index, record& tracking) {
				// Get the first element
				int a = stack::get<int>(L, index);
				// Get the second element,
				// in the +1 position from the first
				bool b = stack::get<bool>(L, index + 1);
				// we use 2 slots, each of the previous takes 1
				tracking.use(2);
				return two_things{ a, b };
			}
		};

		template <>
		struct pusher<two_things> {
			static int push(lua_State* L, const two_things& things) {
				int amount = stack::push(L, things.a);
				amount += stack::push(L, things.b);
				// Return 2 things
				return amount;
			}
		};

		template <>
		struct checker<number_shim> {
			template <typename Handler>
			static bool check(lua_State* L, int index, Handler&& handler, record& tracking) {
				// check_usertype is a backdoor for directly checking sol2 usertypes
				if (!check_usertype<number_shim>(L, index) && !stack::check<double>(L, index)) {
					handler(L, index, type_of(L, index), type::userdata, "expected a number_shim or a number");
					return false;
				}
				tracking.use(1);
				return true;
			}
		};

		template <>
		struct unqualified_getter<number_shim> {
			static number_shim get(lua_State* L, int index, record& tracking) {
				if (check_usertype<number_shim>(L, index)) {
					number_shim& ns = get_usertype<number_shim>(L, index, tracking);
					return ns;
				}
				number_shim ns{};
				ns.num = stack::get<double>(L, index, tracking);
				return ns;
			}
		};

	} // namespace stack
} // namespace sol

struct custom {
	int bweh;

	static int get_calls;
	static int check_calls;
	static int check_get_calls;
	static int push_calls;
	static int exact_push_calls;
};

int custom::get_calls = 0;
int custom::check_calls = 0;
int custom::check_get_calls = 0;
int custom::push_calls = 0;
int custom::exact_push_calls = 0;

custom sol_lua_get(sol::types<custom>, lua_State* L, int index, sol::stack::record& tracking) {
	++custom::get_calls;
	return { sol::stack::get<int>(L, index, tracking) };
}

template <typename Handler>
bool sol_lua_check(sol::types<custom>, lua_State* L, int index, Handler&& handler, sol::stack::record& tracking) {
	++custom::check_calls;
	return sol::stack::check<int>(L, index, std::forward<Handler>(handler), tracking);
}

template <typename Handler>
sol::optional<custom> sol_lua_check_get(sol::types<custom> type_tag, lua_State* L, int index, Handler&& handler, sol::stack::record& tracking) {
	++custom::check_get_calls;
	if (sol_lua_check(type_tag, L, index, std::forward<Handler>(handler), tracking)) {
		return sol_lua_get(type_tag, L, index, tracking);
	}
	return sol::nullopt;
}

int sol_lua_push(lua_State* L, const custom& c) {
	++custom::push_calls;
	// ensure there's enough space for 1 more thing on the stack
	lua_checkstack(L, 1);
	// tell Lua we've left something on
	// the stack: return what comes from pushing an integer
	return sol::stack::push(L, c.bweh);
}

int sol_lua_push(sol::types<custom>, lua_State* L, const custom& c) {
	++custom::exact_push_calls;
	// ensure there's enough space for 1 more thing on the stack
	lua_checkstack(L, 1);
	// tell Lua we've left something on
	// the stack: return what comes from pushing an integer
	return sol::stack::push(L, c.bweh);
}

struct multi_custom {
	int bweh;
	bool bwuh;
	std::string blah;

	static int get_calls;
	static int check_calls;
	static int check_get_calls;
	static int push_calls;
	static int exact_push_calls;
};

int multi_custom::get_calls = 0;
int multi_custom::check_calls = 0;
int multi_custom::check_get_calls = 0;
int multi_custom::push_calls = 0;
int multi_custom::exact_push_calls = 0;

multi_custom sol_lua_get(sol::types<multi_custom>, lua_State* L, int index, sol::stack::record& tracking) {
	++multi_custom::get_calls;
	return {
		sol::stack::get<int>(L, index + 0, tracking), sol::stack::get<bool>(L, index + 1, tracking), sol::stack::get<std::string>(L, index + 2, tracking)
	};
}

template <typename Handler>
bool sol_lua_check(sol::types<multi_custom>, lua_State* L, int index, Handler&& handler, sol::stack::record& tracking) {
	++multi_custom::check_calls;
	bool success = sol::stack::check<int>(L, index + 0, std::forward<Handler>(handler), tracking)
	     && sol::stack::check<bool>(L, index + 1, std::forward<Handler>(handler), tracking)
	     && sol::stack::check<std::string>(L, index + 2, std::forward<Handler>(handler), tracking);
	return success;
}

int sol_lua_push(lua_State* L, const multi_custom& c) {
	++multi_custom::push_calls;
	// ensure there's enough space for 1 more thing on the stack
	lua_checkstack(L, 3);
	int p = sol::stack::push(L, c.bweh);
	p += sol::stack::push(L, c.bwuh);
	p += sol::stack::push(L, c.blah);
	// tell Lua we've left something on
	// the stack: return what comes from pushing an integer
	return p;
}

struct super_custom {
	int bweh;

	static int get_calls;
	static int check_calls;
	static int check_get_calls;
	static int push_calls;
	static int exact_push_calls;
};

int super_custom::get_calls = 0;
int super_custom::check_calls = 0;
int super_custom::check_get_calls = 0;
int super_custom::push_calls = 0;
int super_custom::exact_push_calls = 0;

super_custom* sol_lua_get(sol::types<super_custom*>, lua_State* L, int index, sol::stack::record& tracking) {
	++super_custom::get_calls;
	tracking.use(1);
	void* vp = lua_touserdata(L, index);
	super_custom** pscp = static_cast<super_custom**>(vp);
	return *pscp;
}

super_custom& sol_lua_get(sol::types<super_custom>, lua_State* L, int index, sol::stack::record& tracking) {
	return *sol_lua_get(sol::types<super_custom*>(), L, index, tracking);
}

template <typename Handler>
bool sol_lua_check(sol::types<super_custom>, lua_State* L, int index, Handler&& handler, sol::stack::record& tracking) {
	++super_custom::check_calls;
	tracking.use(1);
	if (luaL_testudata(L, index, "super_custom!") == nullptr) {
		if (luaL_testudata(L, index, "super_custom!p") == nullptr) {
			handler(L, index, sol::type::userdata, sol::type_of(L, index), "not a super_custom ?!");
			return false;
		}
	}
	return true;
}

int sol_lua_push(lua_State* L, const super_custom& c) {
	++super_custom::push_calls;
	// ensure there's enough space for 1 more thing on the stack
	lua_checkstack(L, 1);
	// tell Lua we've left something on
	// the stack: return what comes from pushing an integer
	void* ud = lua_newuserdata(L, sizeof(super_custom*) + sizeof(super_custom));
	super_custom* tud = static_cast<super_custom*>(static_cast<void*>(static_cast<char*>(ud) + sizeof(super_custom*)));
	*static_cast<super_custom**>(ud) = tud;
	*tud = c;
	luaL_newmetatable(L, "super_custom!");
	lua_setmetatable(L, -2);
	return 1;
}

int sol_lua_push(lua_State* L, super_custom* c) {
	++super_custom::push_calls;
	// ensure there's enough space for 1 more thing on the stack
	lua_checkstack(L, 1);
	// tell Lua we've left something on
	// the stack: return what comes from pushing an integer
	void* ud = lua_newuserdata(L, sizeof(super_custom*));
	*static_cast<super_custom**>(ud) = c;
	luaL_newmetatable(L, "super_custom!p");
	lua_setmetatable(L, -2);
	return 1;
}

int sol_lua_push(lua_State* L, std::reference_wrapper<super_custom> c) {
	return sol::stack::push(L, std::addressof(c.get()));
}

TEST_CASE("customization/split struct", "using the newly documented customization points to handle different kinds of classes") {
	sol::state lua;

	// Create a pass-through style of function
	auto result1 = lua.safe_script("function f ( a, b, c ) return a + c, b end");
	REQUIRE(result1.valid());
	lua.set_function("g", [](int a, bool b, int c, double d) { return std::make_tuple(a + c, b, d + 2.5); });

	// get the function out of Lua
	sol::function f = lua["f"];
	sol::function g = lua["g"];

	two_things thingsf = f(two_things{ 24, true }, 1);
	two_things thingsg;
	double d;
	sol::tie(thingsg, d) = g(two_things{ 25, false }, 2, 34.0);
	REQUIRE(thingsf.a == 25);
	REQUIRE(thingsf.b);

	REQUIRE(thingsg.a == 27);
	REQUIRE_FALSE(thingsg.b);
	REQUIRE(d == 36.5);
}

TEST_CASE("customization/usertype", "using the newly documented customization points to handle different kinds of classes") {
	sol::state lua;

	// Create a pass-through style of function
	auto result1 = lua.safe_script("function f ( a ) return a end");
	REQUIRE(result1.valid());
	lua.set_function("g", [](double a) {
		number_shim ns;
		ns.num = a;
		return ns;
	});

	auto result2 = lua.safe_script("vf = f(25) vg = g(35)", sol::script_pass_on_error);
	REQUIRE(result2.valid());

	number_shim thingsf = lua["vf"];
	number_shim thingsg = lua["vg"];

	REQUIRE(thingsf.num == 25);
	REQUIRE(thingsg.num == 35);
}

TEST_CASE("customization/overloading", "using multi-size customized types in an overload") {
	bool TwoThingsWorks = false, OverloadWorks = false;
	sol::state lua;
	lua["test_two_things"] = [&](two_things) { TwoThingsWorks = true; };
	lua["test_overload"] = sol::overload([&](two_things) { OverloadWorks = true; }, [] {});

	lua.script(
	     "test_two_things(0, true)\n"
	     "test_overload(0, true)");

	REQUIRE(TwoThingsWorks);
	REQUIRE(OverloadWorks);
}

TEST_CASE("customization/adl", "using the ADL customization points in various situations") {
	sol::state lua;
	lua.open_libraries(sol::lib::base);

	SECTION("value-based") {
		custom::get_calls = 0;
		custom::check_calls = 0;
		custom::check_get_calls = 0;
		custom::push_calls = 0;
		custom::exact_push_calls = 0;

		lua["meow"] = custom{ 25 };
		custom meow = lua["meow"];

		REQUIRE(meow.bweh == 25);
		REQUIRE(custom::get_calls > 0);
		REQUIRE(custom::check_calls > 0);
		REQUIRE(custom::check_get_calls > 0);
		REQUIRE(custom::exact_push_calls > 0);
		REQUIRE(custom::push_calls == 0);
	}
	SECTION("multi") {
		multi_custom::get_calls = 0;
		multi_custom::check_calls = 0;
		multi_custom::check_get_calls = 0;
		multi_custom::push_calls = 0;
		multi_custom::exact_push_calls = 0;

		auto result = lua.safe_script("return function (a, b, c) return a, b, c end", sol::script_pass_on_error);
		REQUIRE(result.valid());
		sol::protected_function f = result;
		multi_custom pass_through = f(multi_custom{ 22, false, "miao" });
		REQUIRE(pass_through.bweh == 22);
		REQUIRE_FALSE(pass_through.bwuh);
		REQUIRE(pass_through.blah == "miao");

		REQUIRE(multi_custom::get_calls > 0);
		REQUIRE(multi_custom::check_calls > 0);
		REQUIRE(multi_custom::push_calls > 0);
		REQUIRE(multi_custom::check_get_calls == 0);
		REQUIRE(multi_custom::exact_push_calls == 0);
	}
	SECTION("reference-based") {
		super_custom::get_calls = 0;
		super_custom::check_calls = 0;
		super_custom::check_get_calls = 0;
		super_custom::push_calls = 0;
		super_custom::exact_push_calls = 0;

		super_custom meow_original{ 50 };
		lua["meow"] = std::ref(meow_original);
		super_custom& meow = lua["meow"];
		super_custom meow_copy = lua["meow"];

		REQUIRE(meow.bweh == 50);
		REQUIRE(&meow == &meow_original);
		REQUIRE(meow_copy.bweh == 50);
		REQUIRE(super_custom::get_calls > 0);
		REQUIRE(super_custom::check_calls > 0);
		REQUIRE(super_custom::push_calls > 0);
		REQUIRE(super_custom::check_get_calls == 0);
		REQUIRE(super_custom::exact_push_calls == 0);
	}
}