sol2/tests/environment/source/shadowing.cpp

// sol2

// The MIT License (MIT)

// Copyright (c) 2013-2022 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:

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// 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
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#include <catch2/catch_all.hpp>

#include <sol/sol.hpp>

TEST_CASE("environments/shadowing", "Environments can properly shadow and fallback on variables") {

	sol::state lua;
	sol::stack_guard luasg(lua);

	lua["b"] = 2142;

	SECTION("no fallback") {
		sol::environment plain_env(lua, sol::create);
		auto result1 = lua.safe_script("a = 24", plain_env, sol::script_pass_on_error);
		REQUIRE(result1.valid());
		REQUIRE(result1.status() == sol::call_status::ok);
		sol::optional<int> maybe_env_a = plain_env["a"];
		sol::optional<int> maybe_global_a = lua["a"];
		sol::optional<int> maybe_env_b = plain_env["b"];
		sol::optional<int> maybe_global_b = lua["b"];

		REQUIRE(maybe_env_a != sol::nullopt);
		REQUIRE(maybe_env_a.value() == 24);
		REQUIRE(maybe_env_b == sol::nullopt);

		REQUIRE(maybe_global_a == sol::nullopt);
		REQUIRE(maybe_global_b != sol::nullopt);
		REQUIRE(maybe_global_b.value() == 2142);
	}
	SECTION("fallback") {
		sol::environment env_with_fallback(lua, sol::create, lua.globals());
		auto result1 = lua.safe_script("a = 56", env_with_fallback, sol::script_pass_on_error);
		REQUIRE(result1.valid());
		REQUIRE(result1.status() == sol::call_status::ok);
		sol::optional<int> maybe_env_a = env_with_fallback["a"];
		sol::optional<int> maybe_global_a = lua["a"];
		sol::optional<int> maybe_env_b = env_with_fallback["b"];
		sol::optional<int> maybe_global_b = lua["b"];

		REQUIRE(maybe_env_a != sol::nullopt);
		REQUIRE(maybe_env_a.value() == 56);
		REQUIRE(maybe_env_b != sol::nullopt);
		REQUIRE(maybe_env_b.value() == 2142);

		REQUIRE(maybe_global_a == sol::nullopt);
		REQUIRE(maybe_global_b != sol::nullopt);
		REQUIRE(maybe_global_b.value() == 2142);
	}
	SECTION("from name") {
		sol::environment env_with_fallback(lua, sol::create, lua.globals());
		lua["env"] = env_with_fallback;
		sol::environment env = lua["env"];
		auto result1 = lua.safe_script("a = 56", env, sol::script_pass_on_error);
		REQUIRE(result1.valid());
		sol::optional<int> maybe_env_a = env["a"];
		sol::optional<int> maybe_global_a = lua["a"];
		sol::optional<int> maybe_env_b = env["b"];
		sol::optional<int> maybe_global_b = lua["b"];

		REQUIRE(maybe_env_a != sol::nullopt);
		REQUIRE(maybe_env_a.value() == 56);
		REQUIRE(maybe_env_b != sol::nullopt);
		REQUIRE(maybe_env_b.value() == 2142);

		REQUIRE(maybe_global_a == sol::nullopt);
		REQUIRE(maybe_global_b != sol::nullopt);
		REQUIRE(maybe_global_b.value() == 2142);
	}
	SECTION("name with newtable") {
		lua["blank_env"] = sol::new_table(0, 1);
		sol::environment plain_env = lua["blank_env"];
		auto result1 = lua.safe_script("a = 24", plain_env, sol::script_pass_on_error);
		REQUIRE(result1.valid());

		sol::optional<int> maybe_env_a = plain_env["a"];
		sol::optional<int> maybe_global_a = lua["a"];
		sol::optional<int> maybe_env_b = plain_env["b"];
		sol::optional<int> maybe_global_b = lua["b"];

		REQUIRE(maybe_env_a != sol::nullopt);
		REQUIRE(maybe_env_a.value() == 24);
		REQUIRE(maybe_env_b == sol::nullopt);

		REQUIRE(maybe_global_a == sol::nullopt);
		REQUIRE(maybe_global_b != sol::nullopt);
		REQUIRE(maybe_global_b.value() == 2142);
	}
}